The complete lack of information about such common devices as uninterruptible power supplies is surprising. We are breaking through the information blockade and are starting to publish materials on their design and repair. From the article you will get a general idea of the existing types of uninterruptible power supplies and a more detailed one, at the level schematic diagram, - about the most common Smart-UPS models.
The reliability of computers is largely determined by the quality of the electrical network. The consequences of power outages such as surges, rises, dips and loss of voltage can include keyboard locking, data loss, damage to the system board, etc. To protect expensive computers from troubles associated with the power network, uninterruptible power supplies (UPS) are used. A UPS allows you to get rid of problems associated with poor quality power supply or its temporary absence, but is not a long-term alternative source of power supply, like a generator.
According to the SK PRESS expert and analytical center, in 2000 the sales volume of UPS on the Russian market amounted to 582 thousand units. If we compare these estimates with data on computer sales (1.78 million units), it turns out that in 2000, every third computer purchased was equipped with an individual UPS.
The vast majority of the Russian UPS market is occupied by products from six companies: APC, Chloride, Invensys, IMV, Liebert, Powercom. APC products have been maintaining a leading position in the Russian UPS market for many years now.
UPSs are divided into three main classes: Off-line (or stand-by), Line-interactive and On-line. These devices have different designs and characteristics.
Rice. 1. Block diagram of an Off-line class UPS
The block diagram of an Off-line class UPS is shown in Fig. 1. During normal operation, the load is supplied with filtered mains voltage. To suppress electromagnetic and radio frequency interference in input circuits, EMI/RFI Noise filters are used on metal-oxide varistors. If the input voltage becomes lower or higher than the set value or disappears altogether, the inverter is turned on, which is normally in the off state. By converting the DC voltage of the batteries into alternating voltage, the inverter powers the load from the batteries. The shape of its output voltage is rectangular pulses of positive and negative polarity with an amplitude of 300 V and a frequency of 50 Hz. Off-line class UPSs operate uneconomically in electrical networks with frequent and significant voltage deviations from the rated value, since frequent switching to battery operation reduces the battery life. The power of the Back-UPS model Off-line class UPS produced by APC is in the range of 250...1250 VA, and the Back-UPS Pro model is in the range of 2S0...1400 VA.
Rice. 2. Block diagram of Line-interactive class UPS
The block diagram of a Line-interactive class UPS is shown in Fig. 2. Just like Off-line class UPSs, they retransmit AC voltage power supply to the load, while absorbing relatively small voltage surges and smoothing out interference. The input circuits use Metal Oxide Varistor EMI/RFI Noise Filter to suppress EMI and RFI. If an accident occurs in the power grid, the UPS synchronously, without loss of the oscillation phase, turns on the inverter to power the load from the batteries, while the sinusoidal shape of the output voltage is achieved by filtering the PWM oscillation. The circuit uses a special inverter to recharge the battery, which also works during power surges. The range of operation without connecting a battery is expanded due to the use of an autotransformer with a switchable winding in the input circuits of the UPS. The switch to battery power occurs when the mains voltage goes out of range. The power of Line-interactive UPS class Smart-UPS manufactured by APC is 250...5000 VA.
Rice. 3. Block diagram of an On-line class UPS
The block diagram of an On-line class UPS is shown in Fig. 3. These UPSs convert AC input voltage to DC, which is then converted back into AC with stable parameters using a PWM inverter. Since the load is always supplied by the inverter, there is no need to switch from the external network to the inverter, and the switching time is zero. Due to the inertial DC link, which is the battery, the load is isolated from network anomalies and a very stable output voltage is generated. Even with large deviations in input voltage, the UPS continues to supply the load with pure sinusoidal voltage with a deviation of no more than +5% from the user-set nominal value. APC On-line class UPSs have the following output powers: Matrix UPS models - 3000 and 5000 VA, Symmetra Power Array models - 8000, 12000 and 16000 VA.
Back-UPS models do not use a microprocessor, but Back-UPS Pro, Smart-UPS, Smart/VS, Matrix and Symmetna models do use a microprocessor.
The most widely used devices are: Back-UPS, Back-UPS pro, Smart-UPS, Smart-UPS/VS.
Devices such as Matrix and Symmetna are used primarily for banking systems.
In this article we will look at the design and diagram of Smart-UPS 450VA...700VA models used for power supply personal computers(PC) and servers. Their technical characteristics are given in table. 1.
Table 1. Specifications Smart-UPS models from APC
| Model | 450VA | 620VA | 700VA | 1400VA |
|---|---|---|---|---|
| Allowable input voltage, V | 0...320 | |||
| Input voltage when operating from the network *, V | 165...283 | |||
| Output voltage *, V | 208...253 | |||
| Input circuit overload protection | Resettable circuit breaker | |||
| Frequency range when operating from mains, Hz | 47...63 | |||
| Switching time to battery power, ms | 4 | |||
| Maximum load power, VA (W) | 450(280) | 620(390) | 700(450) | 1400(950) |
| Output voltage when operating on battery, V | 230 | |||
| Frequency when operating on battery power, Hz | 50 ± 0.1 | |||
| Waveform when running on battery | Sine wave | |||
| Output circuit overload protection | Overload protection and short circuit, when overloaded, switch off with latching | |||
| Battery Type | Lead sealed, maintenance free | |||
| Number of batteries x voltage, V, | 2 x 12 | 2 x 6 | 2 x 12 | 2 x 12 |
| Battery capacity, Ah | 4,5 | 10 | 7 | 17 |
| Battery life, years | 3...5 | |||
| Full charge time, h | 2...5 | |||
| UPS dimensions (height x width x length), cm | 16.8x11.9x36.8 | 15.8x13.7x35.8 | 21.6x17x43.9 | |
| Net weight (gross), kg | 7,30(9,12) | 10,53(12,34) | 13,1(14,5) | 24,1(26,1) |
*Adjustable by user using software PowerChute.
UPS Smart-UPS 450VA...700VA and Smart-UPS 1000VA...1400VA have the same electrical diagram and differ in battery capacity, number of output transistors in the inverter, power transformer power and dimensions.
Let's consider the parameters characterizing the quality of electricity, as well as terminology and designations.
Power problems can be expressed as:
In Russia, dips, dropouts and voltage surges, both up and down, account for approximately 95% of deviations from the norm, the rest is noise, impulse noise (needles), and high-frequency surges.
The units used to measure power are Volt-Amps (VA, VA) and Watts (W, W). They differ in power factor PF (Power Factor):
The power factor for computer equipment is 0.6...0.7. The number in the designation of APC UPS models means the maximum power in VA. For example, the Smart-UPS 600VA model has a power of 400 W, and the 900VA model has a power of 630 W.
The block diagram of the Smart-UPS and Smart-UPS/VS models is shown in Fig. 4. The mains voltage is supplied to the EM/RFI input filter, which serves to suppress interference from the mains. At the rated mains voltage, relays RY5, RY4, RY3 (pins 1, 3), RY2 (pins 1, 3), RY1 are turned on, and the input voltage passes to the load. Relays RY3 and RY2 are used for the BOOST/TRIM output voltage adjustment mode. For example, if the network voltage has increased and gone beyond the permissible limit, relays RY3 and RY2 connect the additional winding W1 in series with the main winding W2. An autotransformer is formed with a transformation ratio
K = W2/(W2 + W1)
less than one, and the output voltage drops. In the event of a decrease in the mains voltage, the additional winding W1 is reversed by the relay contacts RY3 and RY2. Transformation ratio
K = W2/(W2 - W1)
becomes greater than unity, and the output voltage increases. The adjustment range is ±12%, the hysteresis value is selected by the Power Chute program.
When the input voltage fails, relays RY2...RY5 are turned off, a powerful PWM inverter powered by the battery is turned on, and a sinusoidal voltage of 230 V, 50 Hz is supplied to the load.
The multi-link power supply noise suppression filter consists of varistors MV1, MV3, MV4, inductor L1, capacitors C14...C16 (Fig. 5). Transformer CT1 analyzes high-frequency components of the network voltage. Transformer CT2 is a load current sensor. Signals from these sensors, as well as the temperature sensor RTH1, are sent to the analog-to-digital converter IC10 (ADC0838) (Fig. 6).
Transformer T1 is an input voltage sensor. The command to turn on the device (AC-OK) is sent from the two-level comparator IC7 to the base Q6. Transformer T2 - output voltage sensor for Smart TRIM/BOOST mode. From pins 23 and 24 of processor IC1 2 (Fig. 6), the BOOST and TRIM signals are supplied to the bases of transistors Q43 and Q49 to switch relays RY3 and RY2, respectively.
The phase synchronization signal (PHAS-REF) from pin 5 of transformer T1 goes to the base of transistor Q41 and from its collector to pin 14 of the IC12 processor (Fig. 6).
The Smart-UPS model uses an IC12 microprocessor (S87C654) that:
The EEPROM IC13 memory chip stores factory settings, as well as calibrated settings for frequency signal levels, output voltage, transition limits, and battery charging voltage.
Digital-to-analog converter IC15 (DAC-08CN) generates a reference sinusoidal signal at pin 2, which is used as a reference for IC17 (APC2010).
The PWM signal is generated by IC14 (APC2020) together with IC17. Powerful field effect transistors Q9...Q14, Q19...Q24 form a bridge inverter. During the positive half-wave of the PWM signal, Q12...Q14 and Q22...Q24 are open, and Q19...Q21 and Q9...Q11 are closed. During the negative half-wave, Q19...Q21 and Q9...Q11 are open, and Q12...Q14 and Q22...Q24 are closed. Transistors Q27...Q30, Q32, Q33, Q35, Q36 form push-pull drivers that generate control signals for powerful field-effect transistors with a large input capacitance. The load of the inverter is the transformer winding, it is connected by wires W5 (yellow) and W6 (black). A sinusoidal voltage of 230 V, 50 Hz is generated on the secondary winding of the transformer to power the connected equipment.
Operation of the inverter in “reverse” mode is used to charge the battery with pulsating current during normal operation UPS.
The UPS has a built-in SNMP slot, which allows you to connect additional cards to expand the capabilities of the UPS:
The UPS has several voltages necessary for normal operation of the device: 24 V, 12 V, 5 V and -8 V. To check them, you can use the table. 2. Measure the resistance from the terminals of the microcircuits to the common wire with the UPS turned off and capacitor C22 discharged. Typical faults of Smart-Ups 450VA...700VA UPS and methods for eliminating them are given in table. 3.
Table 3. Typical faults of Smart-Ups 450VA...700VA UPS
| Brief description of the defect | Possible reason | Troubleshooting method |
|---|---|---|
| UPS does not turn on | Batteries not connected | Connect batteries |
| Bad or faulty battery, its capacity is low | Replace the battery. The capacity of a charged battery can be checked using a high beam lamp from a car (12 V, 150 W) | |
| Powerful field-effect transistors of the inverter are broken | In this case, there is no voltage at the terminals of the battery connected to the UPS board. Check with an ohmmeter and replace the transistors. Check the resistors in their gate circuits. Replace IC16 | |
| Broken flexible cable connecting the display | This problem may be caused by the flex cable terminals shorting on the UPS chassis. Replace the flexible cable connecting the display to the main board of the UPS. Check the serviceability of fuse F3 and transistor Q5 | |
| The power button is pressed in | Replace button SW2 | |
| The UPS turns on only from the battery | Fuse F3 burned out | Replace F3. Check the serviceability of transistors Q5 and Q6 |
| The UPS does not start. Battery replacement indicator lights up | If the battery is good, the UPS does not execute the program correctly. | Calibrate the battery voltage using a proprietary program from APC |
| The UPS does not connect to the line | Torn off network cable or contact is broken | Connect the network cable. Check the serviceability of the automatic plug with an ohmmeter. Check the hot-neutral cord connection |
| Cold soldering of board elements | Check the serviceability and quality of soldering of elements L1, L2 and especially T1 | |
| Varistors are faulty | Check or replace varistors MV1...MV4 | |
| When the UPS is turned on, the load is shed | Voltage sensor T1 is faulty | Replace T1. Check the serviceability of the elements: D18...D20, C63 and C10 |
| Display indicators are flashing | The capacitance of capacitor C17 has decreased | Replace capacitor C17 |
| Possible capacitor leakage | Replace C44 or C52 | |
| Relay contacts or board elements are faulty | Replace relay. Replace IC3 and D20. It is better to replace diode D20 with 1N4937 | |
| UPS overload | The power of the connected equipment exceeds the rated power | Reduce load |
| Transformer T2 is faulty | Replace T2 | |
| Current sensor ST1 is faulty | Replace ST1. Resistance greater than 4 ohms indicates a faulty current sensor | |
| IC15 is faulty | Replace IC15. Check voltage -8 V and 5 V. Check and replace if necessary: IC12, IC8, IC17, IC14 and inverter power field-effect transistors. Check the windings of the power transformer | |
| Battery won't charge | The UPS program is not working correctly | Calibrate the battery voltage using a proprietary program from APC. Check constants 4, 5, 6, 0. Constant 0 is critical for each UPS model. Check the constant after replacing the battery |
| The battery charging circuit is faulty | Replace IC14. Check the voltage of 8 V on the pin. 9 IC14, if it is missing, then replace C88 or IC17 | |
| Battery faulty | Replace the battery. Its capacity can be checked with a high beam lamp from a car (12 V, 150 W) | |
| Microprocessor IC12 is faulty | Replace IC12 | |
| When turned on, the UPS does not start, a clicking sound is heard | Reset circuit faulty | Check serviceability and replace faulty elements: IC11, IC15, Q51...Q53, R115, C77 |
| Indicator defect | Indication circuit is faulty | Check and replace faulty Q57...Q60 on the indicator board |
| The UPS does not work in On-line mode | Defective board elements | Replace Q56. Check the serviceability of the elements: Q55, Q54, IC12. IC13 is faulty or will need to be reprogrammed. The program can be taken from a working UPS |
| When switching to battery operation, the UPS turns off and turns on spontaneously | Transistor Q3 is broken | Replace transistor Q3 |
In the second part of the article, the On-line class UPS device will be considered,
OFF-LINE CLASS UPS DEVICE
Off-line UPSs from APC include Back-UPS models. UPSs of this class are low-cost and are designed to protect personal computers, workstations, network equipment, retail and point-of-sale terminals. The power of produced Back-UPS models is from 250 to 1250 VA. Basic technical data of the most common UPS models are presented in table. 3.
Table 3. Basic technical data of Back-UPS class UPS
| Model | BK250I | BK400I | BK600I |
|---|---|---|---|
| Rated input voltage, V | 220...240 | ||
| Rated network frequency, Hz | 50 | ||
| Energy of absorbed emissions, J | 320 | ||
| Peak surge current, A | 6500 | ||
| IEEE 587 Cat. Voltage Surge Values Missed in Normal Mode. A 6kVA, % | <1 | ||
| Switching voltage, V | 166...196 | ||
| Output voltage when operating from batteries, V | 225 ± 5% | ||
| Output frequency when operating from batteries, Hz | 50 ± 3% | ||
| Maximum power, VA (W) | 250(170) | 400(250) | 600(400) |
| Power factor | 0,5. ..1,0 | ||
| Crest factor | <5 | ||
| Nominal switching time, ms | 5 | ||
| Number of batteries x voltage, V | 2x6 | 1x12 | 2x6 |
| Battery capacity, Ah | 4 | 7 | 10 |
| 90% recharge time after discharging to 50%, hour | 6 | 7 | 10 |
| Acoustic noise at a distance of 91 cm from the device, dB | <40 | ||
| UPS operating time at full power, min | >5 | ||
| Maximum dimensions (H x W x D), mm | 168x119x361 | ||
| Weight, kg | 5,4 | 9,5 | 11,3 |
The index “I” (International) in the names of UPS models means that the models are designed for an input voltage of 230 V. The devices are equipped with sealed lead-free maintenance-free batteries with a service life of 3...5 years according to the Euro Bat standard. All models are equipped with limiting filters that suppress surges and high-frequency interference in the mains voltage. The devices emit appropriate sound signals when the input voltage is lost, the batteries are low, or there is an overload. The threshold value of the mains voltage, below which the UPS switches to battery operation, is set by switches on the rear panel of the device. Models BK400I and BK600I have an interface port that connects to a computer or server to automatically shut down the system, a test switch, and a buzzer switch.
The block diagram of the Back-UPS 250I, 400I and 600I is shown in Fig. 8. The mains voltage is supplied to the input multi-stage filter through a circuit breaker. The circuit breaker is designed as a circuit breaker on the rear panel of the UPS. In the event of a significant overload, it disconnects the device from the network, while the contact column of the switch is pushed upward. To turn on the UPS after an overload, it is necessary to return the contact column of the switch to its original position. The input filter-limiter of electromagnetic and radio frequency interference uses LC links and metal oxide varistors. During normal operation, contacts 3 and 5 of relay RY1 are closed, and the UPS transmits mains voltage to the load, filtering high-frequency interference. The charging current flows continuously as long as there is voltage in the network. If the input voltage drops below the set value or disappears altogether, or if it is very noisy, contacts 3 and 4 of the relay close, and the UPS switches to operation from the inverter, which converts the DC voltage of the batteries into AC. The switching time is about 5 ms, which is quite acceptable for modern switching power supplies for computers. The load signal shape is rectangular pulses of positive and negative polarity with a frequency of 50 Hz, a duration of 5 ms, an amplitude of 300 V, an effective voltage of 225 V. At idle, the duration of the pulses is reduced and the effective output voltage drops to 208 V. Unlike Smart models -UPS, Back-UPS does not have a microprocessor; comparators and logic chips are used to control the device.
The schematic diagram of the Back-UPS 250I, 400I and 600I UPS is almost completely shown in Fig. 9...11. The multi-link power supply noise suppression filter consists of varistors MOV2, MOV5, chokes L1 and L2, capacitors C38 and C40 (Fig. 9). Transformer T1 (Fig. 10) is an input voltage sensor. Its output voltage is used to charge batteries (D4...D8, IC1, R9...R11, C3 and VR1 are used in this circuit) and analyze the mains voltage.
If it disappears, then the circuit on elements IC2...IC4 and IC7 connects a powerful inverter powered by a battery. The ACFAIL command to turn on the inverter is generated by IC3 and IC4. A circuit consisting of comparator IC4 (pins 6, 7, 1) and electronic key IC6 (pins 10, 11, 12) allows the inverter to operate with a log signal. "1" arriving at pins 1 and 13 of IC2.
A divider consisting of resistors R55, R122, R1 23 and switch SW1 (pins 2, 7 and 3, 6), located on the rear side of the UPS, determines the mains voltage, below which the UPS switches to battery power. This voltage is factory set to 196 V. In areas where the mains voltage fluctuates frequently, resulting in frequent UPS transfers to battery power, the threshold voltage should be set to a lower level. Fine adjustment of the threshold voltage is performed by resistor VR2.
During battery operation, IC7 generates inverter excitation pulses PUSHPL1 and PUSHPL2. Power field-effect transistors Q4...Q6 and Q36 are installed in one arm of the inverter, and Q1...Q3 and Q37 in the other. The transistors are loaded with their collectors onto the output transformer. A pulse voltage with an effective value of 225 V and a frequency of 50 Hz is generated on the secondary winding of the output transformer, which is used to power the equipment connected to the UPS. The duration of the pulses is regulated by variable resistor VR3, and the frequency by resistor VR4 (Fig. 10). Turning the inverter on and off is synchronized with the mains voltage by a circuit on elements IC3 (pins 3...6), IC6 (pins 3...5, 6, 8, 9) and IC5 (pins 1...3 and 11... 13). Circuit based on elements SW1 (pins 1 and 8), IC5 (pins 4...V and 8...10), IC2 (pins 8...10), IC3 (pins 1 and 2), IC10 (pins 12 and 13), D30, D31, D18, Q9, BZ1 (Fig. 11) turns on an audible signal to warn the user of power problems. During battery operation, the UPS emits a single beep every 5 seconds to indicate the need to save user files because Battery capacity is limited. When operating on battery power, the UPS monitors its capacity and emits a continuous beep for a certain time before it is discharged. If pins 4 and 5 of switch SW1 are open, then this time is 2 minutes, if closed - 5 minutes. To turn off the sound signal, you need to close pins 1 and 8 of switch SW1.
All Back-UPS models, with the exception of the BK250I, have a bidirectional communication port for communication with a PC. Power Chute Plus software allows the computer to both monitor the UPS and securely automatically shut down the operating system (Novell, Netware, Windows NT, IBM OS/2, Lan Server, Scounix and UnixWare, Windows 95/98), preserving user files. In Fig. 11 this port is designated J14. Purpose of its pins: 1 - UPS SHUTDOWN. The UPS turns off if a log appears on this pin. "1" for 0.5 s.
2 - AC FAIL. When switching to battery power, the UPS generates a log on this pin. "1".
3 - CC AC FAIL. When switching to battery power, the UPS generates a log at this pin. "0". Open collector output.
4, 9 - DB-9 GROUND. Common wire for input/output signals. The output has a resistance of 20 Ohms relative to the common wire of the UPS.
5 - CC LOW BATTERY. In the event of a low battery, the UPS generates a log at this output. "0". Open collector output.
6 - OS AC FAIL When switching to battery power, the UPS generates a log on this pin. "1". Open collector output.
7, 8 - not connected.
Open collector outputs can be connected to TTL circuits. Their load capacity is up to 50 mA, 40 V. If you need to connect a relay to them, then the winding should be bypassed with a diode.
A regular “null modem” cable is not suitable for communication with this port; a corresponding RS-232 interface cable with a 9-pin connector is supplied with the software.
UPS CALIBRATION AND REPAIR
Setting the output voltage frequency
To set the frequency of the output voltage, connect an oscilloscope or frequency meter to the UPS output. Switch the UPS to battery mode. When measuring the frequency at the UPS output, adjust resistor VR4 to 50 ± 0.6 Hz.
Setting the output voltage value
Switch the UPS into battery mode without load. Connect a voltmeter to the UPS output to measure the effective voltage value. By adjusting resistor VR3, set the voltage at the UPS output to 208 ± 2 V.
Setting the threshold voltage
Set switches 2 and 3 located on the rear side of the UPS to the OFF position. Connect the UPS to a transformer type LATR with continuously adjustable output voltage. Set the voltage at the LATR output to 196 V. Turn resistor VR2 counterclockwise until it stops, then slowly turn resistor VR2 clockwise until the UPS switches to battery power.
Setting the charge voltage
Set the voltage at the UPS input to 230 V. Disconnect the red wire going to the positive terminal of the battery. Using a digital voltmeter, adjust the resistor VR1 to set the voltage on this wire to 13.76 ± 0.2 V relative to the common point of the circuit, then restore the connection to the battery.
Typical faults
Typical faults and methods for eliminating them are given in table. 4, and in table. 5 - analogues of the most frequently failing components.
Table 4. Typical Back-UPS 250I, 400I and 600I faults
| Defect manifestation | Possible reason | Method for finding and eliminating a defect |
|---|---|---|
| Smell of smoke, UPS does not work | Input filter faulty | Check the serviceability of components MOV2, MOV5, L1, L2, C38, C40, as well as the board conductors connecting them |
| The UPS does not turn on. The indicator does not light up | Input circuit breaker (circuit breaker) of the UPS is disabled | Reduce the load on the UPS by turning off part of the equipment, and then turn on the circuit breaker by pressing the circuit breaker contact column |
| Batteries are faulty | Replace batteries | |
| Batteries are not connected correctly | Check that the batteries are connected correctly | |
| Inverter faulty | Check the serviceability of the inverter. To do this, disconnect the UPS from the AC mains, disconnect the batteries and discharge capacitance C3 with a 100 Ohm resistor, test the drain-source channels of powerful field-effect transistors Q1...Q6, Q37, Q36 with an ohmmeter. If the resistance is several ohms or less, then replace the transistors. Check the resistors in the gates R1...R3, R6...R8, R147, R148. Check the serviceability of transistors Q30, Q31 and diodes D36...D38 and D41. Check fuses F1 and F2 | |
| Replace IC2 | ||
| When turned on, the UPS switches off the load | Transformer T1 is faulty | Check the serviceability of the windings of transformer T1. Check the tracks on the board connecting the T1 windings. Check fuse F3 |
| The UPS operates on batteries despite the fact that there is mains voltage | The power supply voltage is very low or distorted | Check the input voltage using an indicator or meter. If this is acceptable for the load, reduce the sensitivity of the UPS, i.e. change the response limit using switches located on the rear wall of the device |
| The UPS turns on, but no voltage is supplied to the load | Relay RY1 is faulty | Check the serviceability of relay RY1 and transistor Q10 (BUZ71). Check the serviceability of IC4 and IC3 and the supply voltage at their terminals |
| Check the tracks on the board connecting the relay contacts | ||
| The UPS hums and/or shuts down the load without providing the expected backup time | The inverter or one of its elements is faulty | See sub-item “Inverter faulty” |
| UPS does not provide expected power backup time | Batteries are discharged or have lost capacity | Charge the batteries. They require recharging after prolonged power outages. In addition, batteries age quickly when used frequently or in high temperature environments. If the batteries are approaching the end of their service life, it is advisable to replace them, even if the battery replacement alarm has not yet sounded. Check the capacity of the charged battery with a 12 V, 150 W car high beam lamp |
| UPS is overloaded | Reduce the number of consumers at the UPS output | |
| UPS does not turn on after replacing batteries | Incorrect connection of batteries when replacing them | Check that the batteries are connected correctly |
| When turned on, the UPS emits a loud tone, sometimes with a decreasing tone | Defective or severely discharged batteries | Charge the batteries for at least four hours. If the problem persists after recharging, the batteries should be replaced. |
| Batteries are not charging | Diode D8 is faulty | Check the serviceability of D8. Its reverse current should not exceed 10 μA |
| Charge voltage below required level | Calibrate battery charge voltage |
Table 5. Analogues for replacing faulty components
| Circuit designation | Faulty component | Possible replacement |
|---|---|---|
| IC1 | LM317T | LM117H, LM117K |
| IC2 | CD4001 | K561LE5 |
| IC3, IC10 | 74С14 | It is made up of two K561TL1 microcircuits, the conclusions of which are connected according to the pinout on the microcircuit |
| IC4 | LM339 | K1401SA1 |
| IC5 | CD4011 | K561LA7 |
| IC6 | CD4066 | K561KT3 |
| D4...D8, D47, D25...D28 | 1N4005 | 1N4006, 1N4007, BY126, BY127, BY133, BY134, 1N5618... 1N5622, 1N4937 |
| Q10 | BUZ71 | BUZ10, 2SK673, 2SK971, BUK442...BUK450, BUK543...BUK550 |
| Q22 | IRF743 | IRF742, MTP10N35, MTP10N40, 2SK554, 2SK555 |
| Q8, Q21, Q35, Q31, Q12, Q9, Q27, Q28, Q32, Q33 | PN2222 | 2N2222, BS540, BS541, BSW61...BSW 64, 2N4014 |
| Q11, Q29, Q25, Q26, Q24 | PN2907 | 2N2907, 2N4026...2N4029 |
| Q1...Q6, Q36, Q37 | IRFZ42 | BUZ11, BUZ12, PRFZ42 |
Gennady Yablonin
"Electronic equipment repair"
There are everyday features that every person encounters almost regularly, it’s worth at least remembering the prevention on television, but nothing is as annoying as a sudden power outage. But it would be okay if the loss of electricity only led to inconvenience, but in reality such “pranks” can result in the breakdown of electronics, and we are talking not only about PCs or related devices, but also about any household appliances in the house.
What can you do to protect yourself from possible breakdowns? There are two established methods:
- Using a surge protector is, to put it simply, an ordinary extension cord that operates on the principle of a filter, that is, high voltage pulses and high-frequency interference are not allowed through, but protection against power outages is not provided;
- Purchase an uninterruptible power supply (UPS) - in addition to the functions of a surge protector, this device is also equipped with a rechargeable battery and a special circuit that controls the voltage in the supply network.
Drawing a conclusion, we can say with confidence that APC UPS uninterruptible power supplies will be able to protect any equipment in the house from premature failure, and in the case of workstations, provide the time for a safe shutdown necessary to save all important data.
Having decided that it’s time to get a UPS, it’s not enough to find the first suitable store and buy a source there (even for a lot of money), you need to choose a reliable manufacturer. The best option would be UPSs from APC (American Power Conversion), and here's why:
- Long-term history of work in the uninterruptible power supply market;
- Worldwide recognition among both professionals and ordinary buyers;
- Market share of 50%.
Characteristics of APC Back-UPS uninterruptible power supplies
When it comes to the characteristics of APC products, there are also several reasons to be proud:
- Contents - in addition to, obviously, the uninterruptible power supply itself, the package often contains not only instructions, but also cables for communication with a PC and modem, as well as a software version for working with UPS parameters remotely from a computer;
- Appearance - expensive plastic is combined here with a pleasant design (the surface is matte, the inside of the sockets is glossy), all connectors are in convenient and logical places, not to mention the sockets according to Euro standards;
- Battery - unfortunately, APC lead-acid batteries are maintenance-free, which means that in case of breakdown you need to contact a specialist immediately. But the batteries function for quite a long time, plus, using a special Master mode, you can automatically divide the load between connected devices, which will extend the overall service life of the batteries;
- Factory diagnostics - this nice feature is that along with the documentation for the UPS, a complete printout of the actual diagnostics of the device is also supplied on call with the signature of the auditor. Agree, solid;
- Charging - practice shows that there is no need to charge the battery for eight to sixteen hours, only four are enough;
- PowerChute - It's easy to see why this software is nicknamed "parachute". Of course, it has nothing to do with jumping from heights, but it has full compatibility with the Windows family, Russification and a clear interface that allows you to programmatically and remotely edit and change the operating parameters of the APC UPS.
Why do you need to buy APC UPS-Back uninterruptible power supplies (UPS) from Anbik?
We have been in the network equipment market for more than five years, but this is not our only competitive advantage:
- We keep product prices at factory prices;
- We guarantee the quality and performance of each UPS from the catalog;
- We deliver to regions of the Russian Federation.
How to buy uninterruptible power supplies (UPS) APC UPS-Back?
It is very simple to purchase APC UPS-back uninterruptible power supplies (UPS) along with related products and in accordance with the equipment passport; you just need to contact the sales managers of our company. We adhere to the highest production standards and are always ready to give you any advice.
An uninterruptible power supply, or as the common people call it UPS (BACK UPS), is essentially a boost converter and charger in one case. The device is very useful, especially for PC owners. The device can autonomously power the computer if for some reason the electricity is suddenly turned off. Unfortunately, the built-in battery does not allow powering the computer for a long time, since its capacity is limited to 7 amperes (in some powerful models the battery costs up to 15-20A). Let's move on to the battery itself.
Uninterruptible voltage sources use a closed gel or acid battery. The built-in battery is usually designed for a capacity of 7 to 8 Ampere/hour, voltage - 12 volts. The battery is completely sealed, which allows you to use the device in any condition. In addition to the battery, inside you can see a huge transformer, in this case 400-500 watts. The transformer operates in two modes -
1) as a step-up transformer for a voltage converter.
2) as a step-down mains transformer for charging the built-in battery.
During normal operation, the load is supplied with filtered mains voltage. Filters are used to suppress electromagnetic and interference in input circuits. If the input voltage becomes lower or higher than the set value or disappears altogether, the inverter is turned on, which is normally in the off state. By converting the DC voltage of the batteries into alternating voltage, the inverter powers the load from the batteries. BACK UPS of the Off-line class operate uneconomically in electrical networks with frequent and significant voltage deviations from the nominal value, since frequent switching to battery operation reduces the battery life. The power of Back-UPS produced by manufacturers is in the range of 250-1200 VA. uninterruptible voltage BACK UPS is quite complex. In the archive you can download a large collection of circuit diagrams, and below are several small copies - click to enlarge.
Here you can find a special controller that is responsible for the correct operation of the device. The controller activates the relay when there is no mains voltage and if the uninterruptible power supply is turned on, it will work as a voltage converter. If the mains voltage appears again, the controller turns off the converter and the device turns into a charger. The capacity of the built-in battery can last up to 10 - 30 minutes, if, of course, the device powers the computer. You can read more about the operation and purpose of uninterruptible power supply units in this book.
BACK UPS can be used as a backup power source; in general, it is recommended that each home have an uninterruptible power supply. If the uninterruptible power supply is intended for domestic needs, then it is advisable to remove the signaling device from the board; it reminds that the device works as a converter; it makes a reminder with a squeak every 5 seconds, and this is annoying. The output of the converter is pure 210-240 volts 50 hertz, but as for the shape of the pulses, it is clearly not a pure sine wave. BACK UPS can power any household appliance, including active ones, of course, if the power of the device allows it.
The APC company has long become almost a monopolist in the power supply market. Almost every user who has a UPS uses the products of this particular company. This is an indicator that the company produces truly high-quality equipment. Strictly speaking, APC is a subsidiary of the giant Shneider Electric. So it is more correct to consider this company as the manufacturer.
As for APC products, they are traditionally of high quality and durable. The company specializes in the production of uninterruptible power supplies, which means that the main criterion in evaluating products is battery life and protection against voltage surges. And with this, APC products are all right. Relatively recently, the company released the APC Back-UPS 650 UPS. This is what we will talk about.
A little about the device
APS Back-UPS 650 is a logical continuation of the series of line-interactive uninterruptible power supplies. The device has all the necessary characteristics, but it is devoid of options that are completely unnecessary for such a device. Some top models are also equipped with a miniature LCD screen, but for such a device it is not particularly needed, since powering the screen also consumes energy. And in terms of battery life, this is not very good. Most UPSs come with simple LED indicators that indicate battery charge level and operating mode.
There are several modifications of this product with the prefixes CS, RS and Pro. They all differ from each other, but only slightly. The difference usually lies in some technical characteristics. It is worth noting that the same output voltage - the hallmark of all APC Back-UPS 650, 230 V uninterruptible power devices - is the limit for them. Even externally, these devices are almost identical. But we need to sort them all out to complete the picture.
CS version
The CS line turns out to be almost the cheapest among the APC 650 series devices. The battery has modest (relatively) characteristics and a standard appearance for devices of this class. Nothing extra. Everything is strictly in order to ensure uninterrupted power supply to computer elements in the event of a power failure.
The APC Back-UPS CS 650 is only available in black. This is a good thing, since black is a universal color. It is in no way capable of spoiling the appearance of the workplace. The asceticism of the UPS APC CS version is even good. Because such devices should work, and not attract attention with a bright appearance. Now let’s see what this “uninterruptible power supply” has, so to speak, under the hood.
Technical characteristics of the CS version
The main criteria by which it is customary to evaluate uninterruptible power supplies are battery capacity and the presence of protection against power surges. Everything else fades into the background. Now let's see what the APC Back-UPS CS 650 can offer us. In principle, like all linear-interactive uninterruptible power supplies, products from APC have standard characteristics, and there is no need to go into them too deeply. But there are still differences. Therefore, we cannot avoid analyzing these very differences. So let's go.
UPS power
This parameter is responsible for stable power supply to all computer components. If there are not enough numbers, then the computer simply will not work. The power of this UPS is 650 VA. This is quite enough for an average PC configuration. For a gaming machine you will have to look for something more powerful.
Battery capacity
This UPS contains a 7.2 A/h battery with an operating voltage of 12 V. How long will it last? Strictly speaking, it all depends on the computer configuration. The more powerful your machine, the less time you have to properly shut down your PC in the event of a crash. However, the average time for moderately configured computers (which is the majority) is 1-3 minutes. Depending on the load on the computer components. Not a bad result. The battery's full charge time (after first switching on) is 22 hours. A bit much, but what can you do? We have to sacrifice something in the name of stability.
Surge protection
This option is present in the APC Back-UPS 650 CS version. Moreover, this component copes with its job with a bang. Numerous tests show that the uninterruptible power supply can equalize the voltage and supply it to the computer. Thus, all components of your computer are reliably protected from power surges.
Connectors and interfaces of the CS version
APS Back-UPS 650 CS version has four connectors for Euro standard power plugs. Moreover, three of them are used to connect devices directly to the battery. They are needed primarily for devices for which constant power supply is critical (system unit, monitor). The fourth connector is for connecting a device that does not require constant power (printer, scanner). The latter is equipped only with a voltage stabilizer.
In addition, the UPS has connectors for protecting the telephone line and another one for connecting an uninterruptible power supply to a PC. Telephone line connectors are needed by those who want to protect their communication devices from voltage surges. You can also connect the UPS to a computer and configure the correct process for shutting down the PC when power is lost. To do this, the package includes a disk with proprietary APC Back-UPS CS 650 software. The instructions included in the package will help you complete this process. Despite statements from some users that nothing in the instruction manual is clear, in our opinion, the instructions are very detailed. It very accurately describes how to work with the device and the operating features of the device itself. There is even a component layout diagram.
RS version
APC Back-UPS RS 650 is an almost complete clone of the CS version. A slight difference is observed only in the technical characteristics of both devices. In appearance, these two devices are indistinguishable, like siblings. Why is that? Apparently, the company decided to save on design. In principle, it is not important for such a device. The main thing is that the device does its job well. And the uninterruptible power supply of the RS version copes with this no worse than its “twin brother”.
If the CS version was intended to work with medium-power computers, then the RS will only handle office PCs. It doesn't have enough power for other tasks. But that doesn't mean he's worse. That's just not what it was made for. If you need a more powerful uninterruptible power supply, then it makes sense to pay attention to the Pro version (more about it below). You will get a good increase in power for almost the same money.
RS Specifications
The APC Back-Ups 650 RS version has its own technical characteristics, which, however, are not very different from those inherent in the devices of the CS version. This is as it should be, since these devices are in the same price niche. Therefore, there cannot be significant differences between them. Let's see what the RS version is like.
Power
The RS version of the uninterruptible power supply has a total power of 650 VA, but it is short-term. The constant is 390 W. This is enough for office computers. But nothing more. And yet the UPS is able to provide professional protection against power surges and sudden power outages.
Battery capacity
The battery installed here is exactly the same as in the CS version. But for some reason the battery life has decreased significantly. Now the user has only 1-1.5 minutes to turn off his PC as required. This may be due to the reduced power of the device. Be that as it may, this is enough for office PCs.
Protection against voltage surges. Strictly speaking, this option is available in all uninterruptible power supplies from APC. And it works as it should. Because without it, the uninterruptible power supply would be just a battery. The RS version was no exception. The protection is present and works well. The voltage surges are leveled out, and a completely even impulse is sent to the PC.
RS version connectors and interfaces
There are no differences here at all. The same four Euro standard connectors with grounding, the same inputs to protect the telephone connection. The same classification, divided into important (battery-powered) and “not so important” (only with a rectifier). The connector for connecting the UPS to the computer is also in place. And the delivery set traditionally includes a disk with proprietary software and an instruction manual. Moreover, the latter contains adequate Russian language. This is another plus for the ARS company.
Battery key
In all versions of APC devices there is also a so-called battery key. It is a plug with flat contacts. It is needed in order to activate the battery and start charging it when the uninterruptible power supply is turned on. When purchasing the UPS it is removed. This is done in order to prevent a battery discharge cycle. This way it will last longer. To activate the device, before turning on the uninterruptible power supply to the network, plug this plug into the connector located right there. After turning on the UPS, the battery charging process will begin.
Pro version
The APC Back-UPS 650 BX650CI Pro version is designed specifically for those who want their computer to last longer on battery power during a power outage. Unlike the RS and CS versions, the Pro version has a battery life of 5.5 minutes. And this is at full load. And in partial mode, the UPS is capable of providing power to the PC for 14-15 minutes. This is an absolute record among devices in this price category.
Differences between Pro and CS and RS
The Pro version is identical to the RS and CS. Same number of connectors and functions. The same voltage rectifiers. Even the battery is from the same manufacturer, only with a larger capacity. It is clear that the Pro version of the UPS will cost a little more, but the difference is not critical. Yes, and it can also be connected to a PC and synchronized. The APC Back-UPS Pro 650 is the ideal line-interactive uninterruptible power supply for the average user. Plus, there is a wonderful price-quality balance.
A modern personal computer is a set of components that are quite expensive. That is why, if something burns out due to a power surge, the user himself will be to blame, and not the power grid. And the careless PC owner will have to tear his hair out. After all, all you had to do was buy a source and all components of the system would remain safe and sound. The UPS not only keeps the computer running during a power outage, but also stabilizes the incoming current, preventing sudden voltage surges. And now we’ll talk about the APC Back-UPS ES 700. This is a good budget solution for the home.
A little about the company
The APC company was founded back in 1981 on the basis of the Massachusetts Institute of Technology. It specialized in the production of voltage stabilizers and uninterruptible power supplies. The company existed in this form until 2007. And then it was bought by the French engineering company Shneider Electric. And now ARS is a subsidiary that produces uninterruptible power supplies for the needs of users.
The company's entry into the Schneider concern did not in any way affect its productivity. Its products are still supplied to the market and enjoy the same popularity among owners of personal computers. The developer’s arsenal includes a variety of models for various needs: from simple blocks to multifunctional combines. The APC Back-UPS ES 700 uninterruptible power supply is a budget option and is suitable for almost everyone. Let's look at it in more detail.
Contents of delivery
The uninterruptible power supply comes in an inconspicuous box made from recycled cardboard. Inside there is the unit itself, a user manual, a warranty card, a bunch of unnecessary papers about safe operation, a connecting cable for connecting to a computer, a 62PC telephone cable and a disk with drivers and software. As you can see, everything is quite strict. Designed in the signature minimalist style of ARS. An interesting thing is lifetime insurance from the manufacturer. It's also included in the kit. According to this document, the company provides a lifetime warranty on its products. And if any component fails, you should send the entire device to the manufacturer (at your own expense) and they will send you a new one. And who will do this for us? It's easier to buy a new one.
The most interesting thing is that the user manual includes Russian. This is a sign that the manufacturing company is truly reputable and wants people to trust it. Many people neglect language support. But not ARS.
Appearance and Design
The APC Back-UPS ES 700 uninterruptible power supply looks like a black plastic box with a bunch of connectors for connecting PC power cables. The body is completely made of durable plastic. The device's battery is hidden at the bottom of the case. Thanks to him, the device turned out to be heavy. There is nothing interesting in the appearance of this UPS. The corporate style of ARS is felt. But nothing more. You can't get much out of design. So it’s better to go straight to the technical specifications.
Specifications
The maximum input voltage going to the device should be 230 Volts. No more. Otherwise, the uninterruptible power supply will not hold up. And no voltage rectifier will help. In this case, the UPS produces a direct current of 230 Volts with all corrections. The output power of the unit is 405 Watt. The operating time of a personal computer from the UPS battery depends on the configuration of the system unit. But the average figures are as follows: at half load - 15 minutes, at full load - 4 minutes. The indicators are average. What was expected at such and such a price.
If the Back-UPS ES 700 beeps, there is something wrong with the battery. The unit is equipped with a special indicator, which also shows if there are problems with the battery. But it can be easily replaced with a new one. Finding the same cartridge will not be difficult. Some “craftsmen” even manage to install car batteries in this UPS. And what? Perfect solution. They live longer. But it is still better to use original components.
Owner reviews
Reviews are incredibly important when choosing a product. They can show how the device behaves in real conditions and how reliable it is. And in the case of uninterruptible power supplies, the last factor is especially important. So what do users say about the APC Back-UPS ES 700 UPS? The price is the first thing that pleased people. It really doesn't cost much. Many owners note the long battery life and built-in technology that prevents the battery from wearing out quickly. The unit operates quietly and is not annoying. It starts to make noise only when it switches to autonomous power supply. In general, almost all owners of this device are satisfied with its performance. And this is the most important thing.
However, there were also dissatisfied comrades. For some, the battery died immediately. Apparently, they came across a device with a manufacturing defect. There were some other complaints about the UPS ES 700. The battery, for example, did not want to be charged. But these are all isolated cases. The owners of ancient computers were especially amused when they said that they did not install drivers. Of course, if they are still running Windows 2000, then this is very likely. You need to carefully read the device specifications. And then such questions will not arise. You also need to operate the uninterruptible power supply correctly and safely. And then there will be no problems with him at all.
Operating rules
In order for the APC Back-UPS ES 700 uninterruptible power supply to last as long as possible and not burn down your apartment, you need to follow basic rules of safe operation. Remember, never install an uninterruptible power supply near heating radiators. Especially in winter. It turns out that uninterruptible power supply batteries are a very delicate thing. When overheated, they flow, flood those parts of the UPS that are energized, and those, in turn, burn out. And it’s good if the body doesn’t melt. So do not place your Back-UPS ES 700 near batteries. The instructions in Russian will probably warn you about this. But who reads it?
Another rule is that pets are not allowed near the uninterruptible power supply. If your cat or dog decides to chew the wires of the uninterruptible power supply, then there are two options for the development of this situation. In the first of them, your pet will be shocked by an electric shock and all subsequent actions to resuscitate it will be useless. In the second option, a short circuit will occur and then a fire. In accordance with all the laws of the genre. Do not let animals play with live devices. It is important.
Features of replacing a device under warranty
The APC company has a very specific vision of the warranty service procedure. They strictly prohibit users from contacting the seller of the uninterruptible power supply. They invite users to send them the damaged device themselves, and the company will send another in return. New. Well, who will do this for us? Especially considering that you will have to send the uninterruptible power supply at your own expense. And our prices for postal services are not particularly encouraging. Moreover, you will have to send it all the way to the USA.
So, we can say with confidence that APC products do not have warranty service as such. At least for our country. After all, imagining our person sending a faulty device somewhere at his own expense is simply beyond imagination. But usually there are no problems with uninterruptible power supplies from APC. And if they do occur, then the sellers meet the customer halfway and replace the defective product themselves.
Conclusion
The APC Back-UPS ES 700 uninterruptible power supply is the optimal solution for home and office. It is easy to use, unpretentious in operation and inexpensive. And the last factor may be decisive for many. The uninterruptible power supply showed itself perfectly when working in real conditions. It’s also nice that the user manual is in Russian. You just need to follow the rules of safe operation. And then the device will work faithfully for quite a long time.