Introduction

1-1. GENERAL
The Dependable Power Systems Uninterruptible Power System is a solid-state double conversion unit that provides continuous, clean, regulated sine wave power to sensitive electronic equipment.
1-2 OPERATION
The Uninterruptible Power System (UPS) has five major components: The rectifier/battery charger, the battery bank, the inverter, the static switch, and the manual (maintenance) bypass switch. During normal operation, the rectifier/charger converts the AC power from the utility to DC power to operate the inverter and charge the batteries. The inverter changes the DC power back to clean, regulated, sine wave power which is supplied through the static switch and the manual bypass switch to the critical load.
Should there be a loss of utility power, the inverter draws the DC power from the batteries without switching to continue providing AC power. In one minute, an alarm will sound to alert operating personnel of a utility failure allowing for an orderly shutdown of the critical load. A second alarm will sound when the batteries are near exhaustion, warning that shutdown is imminent. After the batteries are discharged, the UPS shuts itself off.
After the utility power has returned, the UPS automatically restarts, picks up the load, and starts recharging the batteries.
The static switch is a make-before-break electronic switch that transfers the critical load to the bypass or alternate power source without interruption should the UPS experience a failure or if an overload should occur. If the transfer is due to an overload, the static switch automatically retransfers the critical load back to the inverter after the overload condition ends.
The manual (maintenance) bypass switch, hereon called MBS, is a manually operated
- make-before-break switch. When maintenance is to be performed on the UPS while still supplying power to the critical load, the MBS is placed in the "LOAD ON BYPASS" position. This transfers the load to the bypass AC power source without interruption, allowing all power to be shut down in the UPS.
CAUTION: THE STATIC SWITCH MUST BE IN THE "LOAD ON BYPASS" POSITION BEFORE THE MBS IS THROWN.

ELECTRICAL SPECIFICATIONS
INPUT:
Voltage: +10% to -15% of nominal without discharging the batteries, +/-10% and still recharged the batteries.
2) Frequency: 60Hz +/-5%, optional 50Hz, optional +/-10%
OUTPUT:
1) Voltage: +/-2% total of nominal voltage (Includes line and load)
2) Frequency: +/-0.3% of nominal
3) Harmonic Distortion: Maximum 5% total harmonic distortion
Current Limit: maximum steady state 250% of rated full load current, for fault clearing inverter is capable of supplying up to 500% for 4 milliseconds
5) Overload: 150% for 30 minutes, 125% continuously
6) Wave Form: Sine wave
7) Current Imbalance (3 phase): 0 to 100% of full load
PROTECTION DEVICES:
Input: DC circuit breaker for batteries, AC input breaker, Bypass input to static switch, low voltage shutdown to protect batteries, rectifier fuses, inverter bridge fusees), inverter input to static switch.
Output: The inverter is current limited for protection from shorts and overloads.
SWITCH OPERATIONS:
Static Switch: Make-before-break, automatic transfer & return on overload, automatic transfer on inverter failure.
Manual Bypass Switch: Make-before-break, maintenance switch.
ENVIRONMENT AL CONDITIONS:
Ambient Temperature: 0 to 40 degrees C, 50 degrees C optional. Relative Humidity: 0 to 95% noncondensing.
Barometric Pressure: Sea level to 10,000 feet without deteriorating.