This specification describes a continuous duty solid-state on-line, uninterruptible power supply (U.P.S.). AC power is converted to DC power by a rectifier/charger section, which provides power to operate the inverter and keep the batteries fully charged. The inverter then converts the DC power back to clean, conditioned AC power. The U.P.S. shall operate in conjunction with the existing building/plant electrical systems to provide high quality power to the critical load.

Unless noted otherwise, the design, fabrication, testing, and performance of the system shall be in accordance with the standards and codes, where applicable, of the following agencies:

National Electrical Manufacturers Association (NEMA)

American National Standards Institute (ANSI)

National Electric Code (ANSI/NFPA 70-1993)

Institute of Electrical and Electronic Engineers (IEEE)

International Electrotechnical Commission (IEC)

The system shall operate at rated output without any adverse affects in an ambient temperature of 0 C to 40 C (32 F to 104 F), except batteries.

The system shall operate at a relative humidity of 5% to 95% non-condensing for a temperature range of 10 C to 40 C.

The system shall operate at any altitude from sea level up to 2500m Meters (8,200ft) above sea level without derating.

The UPS system shall be of the float configuration. During any interruption of the AC power input to the U.P.S., the battery bank shall continue to provide input DC power to the inverter with no interruption in inverter output AC power.

Each U.P.S. system, as a minimum, shall consist of the following major components:

AC Rectifier/Charger

Static Inverter

Static Transfer Switch (Zero Break)

Manual Bypass Switch (Zero Break)

Battery Bank

The critical load is continuously supplied by the inverter, with isolated clean AC power. The rectifier/charger derives its power from the commercial AC source and supplies DC power to the inverter while simultaneously float charging the battery. Under normal input to the rectifier/charger, the battery bank may be disconnected from the system without affecting the inverter output.

The inverter output shall maintain phase with the bypass source. If the bypass source deviates more than +/-0.5% of (50 or 60 HZ) the inverter output shall run on its own internal oscillator until the reference source returns to within acceptable limits.

Upon failure of the commercial AC power, the critical load is supplied by the inverter without any interruption; the inverter obtains its power from the storage battery. There shall be no interruption of power to the critical load upon failure or restoration of the commercial source. The inverter frequency shall revert to the internal oscillator.

Upon restoration of the commercial AC power (provided a Low DC Disconnect had not occurred) the rectifier/charger shall recharge the batteries and simultaneously supply DC power the inverter. If a Low DC Disconnect had occurred, a manual closing of the Inverter's DC input breaker must be performed.

Upon pressing the equalize push-button, the charger shall automatically initiate the equalize voltage for the pre-set time on the equalize timer.

Pressing the float push-button any time during the equalize mode shall return the charger to the float voltage.

During an overload or load fault, at the inverter output, the static switch shall automatically transfer the load to commercial power (transfer point factory set @ 120% of rated load) without interruption.

On clearing an inverter malfunction, fault or overload condition, the static transfer switch shall automatically transfer the U.P.S. load from the bypass to the inverter output. The transfer from both directions shall be without interruption (zero-break). A static switch transfer can only be accomplished when the inverter output is in sync with the bypass source. (except during inverter failure)

Transfer to the bypass may also be accomplished manually by the Bypass to Load push button without interruption. This shall lock lout the auto retransfer function.

Upon the deterioration or failure of the inverter bridge output load to bypass without any interruption.

Pressing the Bypass to Load push button while the inverter is supplying the load, the static switch shall transfer the load to the bypass source if the bypass source is available and it is in sync with the inverter. The operation of the Inverter to Load push button is the same as the Bypass to Load push button except it transfers the load to the inverter.

During maintenance, the system may be bypassed without interruption to the load for ease of inspection.

Incoming AC power shall be converted to regulated DC output by the rectifier/charger. The rectifier/charger shall be a constant potential, phase-controlled, solid-state type with constant voltage and current control circuitry. The components within the rectifier shall be capable of operating independently from the remaining system.

The rectifier/charger shall have sufficient capacity to support the total connected load and to recharge the battery at the equalize condition to 90% of full capacity within the specified recharge time.

The primary AC input voltage and frequency shall be as specified on the System Data Sheet.

The input power factor shall be a minimum power factor of 0.75 at nominal input voltage, frequency, and at full-rated load.

Nominal Float Voltage: 130 VDC, adjustable +/-5%

Nominal Equalize Voltage: 140 VDC, adjustable +/-5%

The charger output steady state voltage shall not change more than +/-1% (worst case) at the battery bank, for a cable length less than 10 ft., from no load to full-rated load, with input voltage variation of +10% to-10% and input frequency variation of +/-5%. (+10%-15% without discharging the batteries).

The output ripple shall be less than 2% RMS when connected to a battery bank having an eight hour, ampere hour rating of at least four (4) times the full load ampere rating of the battery charger..

The charger shall be capable of supplying 100% rated full load current at float voltage and -10% input. This shall not cause damage to the charger/rectifier, tripping of circuit breakers, or blown fuses. The current limit shall be adjustable from 50% to 100% of rated output.

An internal screw-type adjustment shall be provided to adjust the float voltage +/-5%.

An internal screw-type adjustment shall be provided to adjust the equalize voltage +/-5%.

An internal 0-100 Hour electronic timer shall be provided to manually place the charger into a high voltage equalize mode for a specific amount of time and then automatically return it to its normal float mode when the time has elapsed.

A dry type isolation transformer shall be supplied on the input to the rectifier with surge/transient protection on the secondary side.

The delta-wye three phase transformer shall be wound with copper wire and use a UL recognized 200` C insulation system.

An epoxy based insulating varnish shall be applied with a VPI

(Vacuum Pressure Impregnation) system to insure a low temperature rise over the 30 year design life of the transformer.

The AC input to the Rectifier/Charger shall be insensitive to phase rotation. The AC input shall be completely isolated from the static bypass circuit.

The Rectifier/Charger shall be capable of supplying 66% of its rated load with the loss of one of its three phase inputs.

The Rectifier/Charger shall be capable of having its DC output terminals paralleled with other chargers and maintain control stability and voltage regulation.

The static inverter shall be a ferroresonant type, which generates single phase AC power. The inverter shall be capable of providing continuous and uninterruptible output power while operating from any DC source within the operating input range.

The inverter bridge shall use power transistors, and Insulated Gate Bipolar Transistors, (IGBT's) to generate the square wave input for the ferroresonant transformer.

The inverter's output circuit shall be magnetically isolated from the input circuit and be supplied with a convenient means of grounding or ungrounding the inverter's output

The inverter's output voltage shall be single phase as specified in the System Data Sheet.

The inverter's output voltage shall be maintained for at least 1/2 cycle during an input bridge failure to insure a zero-break static transfer to the bypass source.

The inverter's output voltages shall be supplied in standard (50 or 60) Hz values

The maximum DC input voltage shall range from 105-147 VDC while maintaining the specified output voltage.

The inverter steady state output voltage regulation shall not change more than +/-2% under any of the following conditions:

1. 0 to 100% and 100% to 0 load change.

2. Minimum to maximum DC bus voltage.

The free-running, steady state output frequency of the Inverter shall not deviate more than 0.1% due to the following conditions;

1. 0% to 100% load

2. Minimum to maximum ambient temperature

3. Minimum to maximum DC bus voltage

The output frequency of the inverter shall be controlled by a crystal controlled oscillator, which can be operated as a free-running unit or as a slave for synchronized operation with a separate AC source. The inverter shall track the AC reference source provided it is (50) (60) +/-0.5% HZ. Upon failure or excessive frequency deviation of the reference the oscillator shall automatically revert to its free-running mode.

The inverter shall be capable of handling linear loads of 0.8 pf -1.0 pf while maintaining a +/-2% regulation and non- linear loads(switch-mode power supplies) with a power factor range of 0.7 to 1.0.

The inverter shall limit the total harmonic distortion of the output voltage to less than 5% RMS total with a 100% linear load or less than 7.5% THD with a 100% switch-mode type load.

The inverter shall be capable of supplying non-linear loads exhibiting a crest factor of up to 3.0 at full load without additional filtering or increasing the size of the system.

The inverter frequency rate of change shall not exceed 1 Hz/second when synchronizing to the bypass reference.

The inverter voltage transient response shall not exceed +8% to -10% due to a 100%-50% or 50%-100% step load change. During a 100% step load the maximum deviation shall be 23% for the first half cycle.

The output voltage, following the step load changes listed above, shall return to within +/-2% of the steady state output voltage within 50 milliseconds.

The inverter shall be capable of supplying loads up to 120% of the rated load for 10 seconds without transfer to the bypass. The inverter shall current limit at approximately 175% and supply up to 500% rated current for approximately one cycle.

Upon heat sink over temperature, the U.P.S. shall automatically transfer the load to the bypass source. If the over temperature occurs for more than 60 seconds, the DC/battery input breaker shall trip protecting the bridge from damage. Manual retransfer of the load o the inverter shall be permitted when the temperature returns to normal.

The DC input shall include an input filter to suppress externally generated DC transients and to control inverter switching transients at the battery. Filtering shall be designed to suppress a transient of 4000 volts, with a 10 micro second duration, occurring at the inverters DC input terminals.

The static switch shall be a naturally commutated, high speed transfer device provided as an integral part of the U.P.S. The control of the unit shall provide an automatic or manual uninterrupted transfer of the load to the bypass.

The static switch shall use inverse parallel connected 600 volt silicon controlled rectifiers with an ampacity suitable to carry ten times the inverter's capacity for one cycle.

The static switch shall automatically connect the bypass source to the critical load and have the following features.

Uninterrupted Transfer - The static switch shall automatically transfer the critical load after the control logic senses one of the following conditions:

1. Inverter Failure

2. Inverter Overcurrent

3. Inverter Output Over/Under Voltage (+/-10%) >16 msec.

4. Low DC Disconnect

5. Manual Transfer via front panel push button

Uninterrupted Automatic Retransfer - If the transfer control switch is set for automatic retransfer, the control circuit shall be capable of retransferring the critical load to the inverter output when the overload is removed and the inverter output is within specification.

Uninterrupted Manual Retransfer - If the transfer control switch is set for manual retransfer, upon manual command the critical load shall be transferred to the inverter.

Transfer Lockout - The transfer logic shall not allow a transfer to the bypass source if one of the following conditions exist:

1. Bypass source out-of-sync with inverter output (Except for upon inverter

failure or low DC disconnect.)

2. Bypass source not available

The transfer time of the static switch shall be zero, resulting in an uninterrupted flow of power to the system loads.

The static switch current sense transfer point shall be adjustable from 100% to 125%, factory set at 120%

The current sense shall be designed to prevent premature switching of the static switch with high crest factor loads.

An internal switch shall be provided to defeat the automatic retransfer of the static switch after a transfer to the bypass source. Shipment setting for the unit shall be OFF (i.e. auto-retransfer not activated).

The static switch shall be designed to fail over to the bypass source. An independent watchdog circuit shall be provided to insure static switch transfer to bypass upon microprocessor failure.

A manually operated mechanical bypass switch shall be provided to facilitate system maintenance. In the bypass position, this switch and the static switch input breaker shall isolate the static switch from the bypass source and connect the output directly to the

bypass power source.

The manual bypass switch shall be mounted in the system enclosure to reduce interconnect wiring.

The manual bypass switch shall be of a "make-before-break" configuration to ensure absolute continuity of AC power to the critical U.P.S. loads during switch over.

The manual bypass switch shall not require the assistance of the static switch to insure a zero break load transfer.

The battery shall operate over the range of 105 to 140 VDC.

Batteries shall be 20 year life expectancy, flooded cell type, complete with 2-tier racks. Batteries shall not be discharged to less than 1.75 volts per cell. Batteries shall be sized to provide the backup time indicated in the attached data sheets at the specified load and power factor in an ambient temperature of 77 degrees fahrenheit.

All controls specified below shall be accessible on the front panel unless otherwise noted.

Inverter to Load - A lighted momentary push button shall be provided to transfer the load to the inverter source.

Bypass to Load - A lighted momentary push button shall be provided to transfer the load to the bypass source.

Float - A momentary push button shall be provided to manually select the float mode on the charger.

Equalize -A momentary push button shall be provided to manually select the equalize mode on the charger.

DC filter capacitors on 20 KVA inverters and larger shall include a current limited precharge circuit, activated by pushbutton.

Indicator Lights and Alarms

The system shall be equipped with the following equipment:

Indicators shall be front replaceable long life LED's, A form "C" contact (SPDT) rated 3 amps@120VAC/28VDC shall be furnished for each specified alarm.

Battery Supplying Load - An indicator (Red) and alarm contact shall be provided to indicate when the battery is suppyling load. The relay shall be normally energized.

Bypass Source Failure - An indicator (Red) and alarm contact shall be provided to indicate when the bypass source has failed. The relay shall be normally energized.

Inverter Supplying Load- An indicator (Amber) shall be provided to indicate when the inverter is powering the load.

Low DC Voltage - An indicator (Red) and alarm contact shall be provided when the inverter DC input voltage is less than 120 VDC. The relay shall be normally energized.

Fan Failure - An indicator (Red) and alarm contact shall be provided when any fan has failed. The relay shall be normally deenergized.

In Sync - An indicator (Green) shall be provided when the internal oscillator of the inverter is synchronized to a bypass reference source that is within +/- 0.5 Hz of (50 or 60) Hz.

Battery Breaker Open Alarm. This alarm shall sense when the Battery Input Breaker is open. An indicator (RED) and alarm contact shall be supplied. The relay shall be energized under normal operation.

Static Switch Transfer - An alarm contact shall be provided to sense when the inverter is supplying power to the load. The relay shall be normally energized.

Indicators shall be supplied to indicate the float and equalize modes of the battery charger.

Indicators shall be supplied to indicate the position of the static switch.

An indicator for inverter pre-charge shall be supplied on inverter sizes larger than 15 KVA.

At a minimum the front panel shall be equipped with the following 3.5 inch scale analog meters (2% accuracy) for the following functions:

Inverter Output Voltmeter

AC Output Ammeter

Inverter Output Frequency Meter (expanded scale)

DC Output Voltmeter

DC Output Ammeter

The overall AC to AC efficiency shall be greater than 78-80% depending on KVA size, with the U.P.S. at full rated load and nominal input voltage.

The overload devices shall not be activated when the system is started under any normal operating conditions.

AC Input Circuit Breaker - A front access molded case breaker shall be provided for charger/rectifier disconnection and overload protection. The A.I.C. rating of the breaker shall be 10KA minimum.

Bypass Circuit Breaker - A front access molded case breaker shall be provided for Bypass disconnection and overload protection. The A.I.C. rating of the breaker shall be 10KA minimum.

Battery Input Circuit Breaker - A molded case breaker shall be provided for DC input disconnection of both input lines and overload protection. The A.I.C. rating of the breaker shall be 10KA minimum.

Semiconductor Fuses - The semiconductors shall be protected from cascaded failure with special fast acting fuses.

The audible noise generated by the unit under rated operating conditions shall not exceed 65dBA at 5 feet away from any side of the enclosure and 3 feet above ground. The sound levels shall be measured with the unit operating at rated load, voltage and frequency.

Forced-air cooling shall be provided when necessary to ensure that all components are operating at below their specified operating temperature.

Wiring materials and practices shall be at a minimum in accordance to UL 1015, 105 C. All wiring and buswork shall be copper throughout the system. PVC insulation shall be used on control wiring only. Power wiring shall use SIS insulation.

Electromagnetic effects shall be minimized to ensure that computer systems, or other similar electronic systems, shall neither adversely affect nor be adversely affected by the system.

The control logic power supply shall incorporate a parallel redundant concept with the inverter DC input and the bypass as a dual source of logic power, to insure control power at all times.

All power transformers or chokes shall be designed using copper windings for reliability and efficiency. The insulation type shall have a temperature rating of at least 200 C

(UL 1446, Class N).

An epoxy based insulating varnish shall be applied with a V P I (Vacuum Pressure Impregnation) system to insure a low temperature rise over the 30 year design life of the transformer.

The nameplate shall be located on the front inside display door and the following minimum information shall be provided on the nameplate:

a. Solidstate Controls, Inc., Model # and Serial #

b. AC Input Voltage, Phase and Frequency

c. Rated AC Input Current

d. Bypass AC Input Voltage, Phase and Frequency

e. DC Input Voltage and Current

f. Rated Output Voltage, Amps, Frequency, Power Factor, KVA and KW.

The enclosure shall be a NEMA-1(IP-20), free standing, with minimum 12GA framework. Door panels shall be a minimum of 14GA steel and side panels shall be a minimum of 18GA.

The enclosure shall be mounted on channels with a 3 inch lifting base open at the front and back to facilitate moving with a fork lift and to provide an entrance area for air movement through the enclosure.

The enclosure shall be designed with blank plates on the sides and rear for installation against a wall. The equipment shall be designed to allow replacement or maintenance of all components from the front.

One or more hinged doors shall be provided in the front with door locks on each. Hinged panels, 36" and larger, shall be provided with a 2 point latching system for holding the panels securely. Removable covers shall be attached with machine screws.

Vermin screens shall be provided to prevent the entry of small animals into the inverter and rectifier/charger cabinets.

Air inlets and outlets shall be protected by screens or perforated metal guards to prevent the entrance of a rod having a diameter of 0.5 inches or longer.

Cable entry shall be through the top or bottom of the cabinet. On UL units, bottom cable entry is recommended.

The connections to the AC output or DC input shall be of the stud type and shall be sized for full load service.

Alarm connections shall be sized to allow connection of 12AWG Wire maximum. The alarm terminal boards shall be rated for 600 VAC.

The system shall be designed to permit front access to modules, fuses, and assemblies. Parts, test points, and terminals shall be placed so they are accessible for circuit checking, adjustment, and maintenance without removal of any adjacent assembly or component or pose a shock hazard.

Permanent wire supports shall be used, no adhesive backed wire supports shall be used.

All point-to-point wires shall be marked with a permanent marking system on both ends of each wire.

All PCB's, indicator lights, meters, controls, semiconductors, and fuses shall be clearly marked with the component designation for ease of serviceability.

The cabinet shall be constructed so that all controls, except float/equalize, are operable with the doors closed, preventing exposure to high voltage terminals. High voltage warning labels shall be visible when any of the cabinet doors are opened.

All external painted surfaces shall be ANSI 61 Gray enamel with a minimum of 2.0 mil thickness and shall be smooth with no runs, sags, or graininess. All internal mounting plates shall be painted white.

The system testing shall be in conformance with IEEE 944-1986 section 7.0, and IEC-146-4. Certified test data shall be supplied to verify test results.

The manufacturer shall have type-test data available to demonstrate system performance with switch-mode type power supplies.

Cabinet outline and interconnect drawings shall be dimensioned and scaled, and include the following information:

Location of any removable plates for Owner's conduit entry.

Location and size of all terminal blocks for Owner's connections.

Location and size of ventilation openings.

Location of cabinet grounds.

Block diagram including currents for customer cable sizing, breaker locations and sizes, and meter locations.

Size and weight of equipment.

Front panel identification chart.

Nominal heat loss for the specified equipment.

Schematic type drawings shall include the following information:

System schematics shall include item designations for all electrical components.

Relay contacts diagrams shall be shown in the deenergized position.

Wire sizes and numbers shall have the same designations that appear in the equipment.

Preparation for shipment shall be in accordance with the manufacturer's standard shipping procedure.

One complete set of instruction books and "as-built" drawings shall be included with the equipment when shipped.

To facilitate site access, shipment of individual cabinets, rather than complete lineups, may be necessary.

Input Voltage : 480

Frequency : 60

DC Output Amps : 300

DC Output Volts: 130

KVA Rating : 30

Phase : 1 Phase

AC Output Voltage: 120

Load Power Factor: 0.8

DC Input Volts : 105 to 140

20 Yr Flooded Battery-Racks

Back Up time Minutes: 15

Type : Lead Acid

Recharge Time Hours : 8