Specifications

2033D Specification

the static switch to energize immediately thus providing an uninterrupted transfer

to the bypass source when any of the following limitations are exceeded:

a. Inverter output undervoltage or overvoltage.

b. Overloads beyond the capability of the inverter.

c. DC circuit undervoltage or overvoltage.

d. Final voltage of system battery is reached (bypass source present and

available).

e. System failure (e.g.: logic fail, fuse blown, etc.).

4.3.2 Automatic Re-transfers

In the event that the critical load must be transferred to the bypass source due to an

overload, the UPS system logic shall monitor the overload condition and, upon the

overload being cleared, perform an automatic re-transfer back to the inverter

output. The UPS sy stem logic shall only allow a re-transfer to occur three times

within a one minute period. Re-transfers shall be inhibited on the fourth transfer

due to the likely hood of a recurring problem at the UPS load distribution. The re-

transfer of load to the inverter shall also be inhibited due to the limitations set in

section 3.3. All retransfers will be inhibited if the inverter and static bypass line

are not synchronized.

4.3.3 Manual Transfers

The UPS shall be capable of transferring the critical load to/from the bypass

source via the front control panel. . If performing manual transfers to inverter or

automatic retransfers, the UPS system logic shall force the inverter output voltage

to match the bypass input voltage and then parallel the inverter and bypass sources

providing a make-before-break transition allowing a controlled walk -in of load

current to the inverter. Manual transfers will be inhibited if the inverter and static

bypass line are not synchronized.

4.3.4 Static Switch

The static switch shall be a high speed transfer device comprised of naturally

commutated SCR's.

5. OPERATOR CONTROL PANEL

5.1 Operator Controls

The operator control panel shall employ the use of a touch screen interface which allows

lock-out of all UPS control functions for security (the Emergency Power Off function shall

not be locked-out). The operator interface shall provide the following: