Tescom T-3250, User Manual, Page: 25 / 42

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IV. OPERATING INSTRUCTIONS
4.1 Introduction
UPS can operate in one of the following operating modes:
a) Normal Operation : All the circuit breakers (except the maintenance by-pass switch) are turned on (“1”
position) and load is connected to the UPS.
b) Maintenance By-Pass Operation : Ups is not in use because of maintenance purposes. Inverter doesn’t
operate and the load is directly connected to the mains (bypass supply) via maintenance bypass switch. (All the
other circuit breakers are in “off” position.
c) “OFF” Position : UPS is totally turned off. All the switches are in “0” position and there is no voltage on the
load.
In this chapter, the procedures of selecting an operation mode are explained in detail.
WARNING !!! SD1 and SD2 circuit breakers are used as the input fuses of the 1st and 2nd rectifiers
respectively. These circuit breakers should be kept in “1” position during all of the operation
modes and turning off procedures.
NOTE1: All the user controls and indicators mentioned in these procedures are identified in chapter 1. For
easier understanding of some procedures there are some repetitions.
NOTE2: The audible alarm may annunciate at various points in these procedures.
4.2 Procedure For Switching The UPS To Power The Load From a Power-Off Condition
TURN ON THE UPS
By applying this procedure UPS returns to normal operation, when it is completely shutdown.
ATTENTION!!! The following actions will apply power to the load equipment.
1. Open the UPS doors to gain access to the main power switches.
2. Make sure that S3 switch (maintenance bypass) is in “0” (OFF) position.
Turn on the S2 (static by-pass) switch (to “1” position).
3. Turn on the S4 (UPS output) switch (to “1” position).
4. Turn on the S1 (inverter input) switch (to ”1” position).
After these procedures, following messages appear on the front panel:
All leds on the front panel are lit for 4 sec. (lamp test)
RECTIFIER START! : Rectifier is working and static bypass continues to supply the load.
INVERTER START! : Inverter is working and static bypass continues to supply the load.
STATUS NORMAL! : The UPS is operating normally, and the inverter is supplying the load.
5. Turn on the battery circuit breaker (to “1” position). By this way it is ensured to connect the battery
group to the UPS.
7. When the green led (L6 led) on the inverter is lit, your UPS system is ready to use. You can start up
your PC., printer etc.