48
WARNING
Risk of
Electric Shock
– Batteries are energy storage devices, and even though all breakers are off,
there still exists the potential of high current flow. For this reason extreme caution should be
exercised at all times during operation or maintenance of the UPS and its external battery cabinets.
Otherwise, maintenance personnel may be exposed to an electrical shock hazard that could result in
death or injury, or damage to the UPS or its electrical loads may occur.
WARNING
Only qualified technicians or supervised personnel should remove and/or replace the batteries.
Batteries have a high short-circuit capacity: MISTAKES IN CONNECTING OR DISCONNECTING
CAN CAUSE CONNECTIONS TO ARC OR WELD AND COULD RESULT IN SEVERE BURNS. DO
NOT TOUCH UNINSULATED BATTERY TERMINALS. Otherwise, maintenance personnel may be
exposed to an electrical shock hazard that could result in death or injury or damage to the UPS or its
electrical loads.
Removing UPS Batteries:
Removing the batteries necessitates opening the front door of the unit.
MAKE SURE THE BATTERY BREAKERS ON THE UPS ARE IN THE OFF POSITION. When the
breakers are in the off position, the batteries have no connection to earth ground, more specifically the
cabinet chassis. This means that accidentally touching a battery terminal to the chassis will not result in
high current flow, as the chassis is no longer connected to the battery circuit. Follow the procedure for
opening the UPS outlined in the previous section. The following precautions should be observed while
working on batteries:
1) Remove watches, rings, or other metal objects.
2) Use tools with insulated handles.
3) Do not lay tools or metal parts on top of batteries.
4) Do not touch battery terminals to any other battery terminals than those terminals intended to
be connected to (watch for inadvertent contact that can occur if not being careful when
removing lead wires to battery terminals).
After opening the front door of the UPS, the battery trays may be unfastened by unscrewing the screw
directly in the front of the tray.
Note:
Remove trays starting from the bottom shelf and with the tray on the right.
Refer to figure 11A for the wiring configuration of a size 1 UPS cabinet and figure 11B for the wiring
configuration of a size 2 UPS cabinet. Remove the black wire from the frontmost terminal, on the front
battery of the rightmost tray, on the bottom shelf of batteries. This is the wire that goes to the rightmost
terminal of the battery breaker. Place this wire so that the removed terminal cannot come in contact
with any of the terminals of any of the batteries. Pull the tray out, resting it on a platform, until the
rearmost terminal of the back battery is exposed. Remove the wire from this terminal along with the
other end which connects to the frontmost terminal on the front battery on the tray to the left, being
careful not to let either end of the wire come in contact with any battery terminals. Once this wire is
removed, the battery tray may be removed from the UPS.
The remaining trays on the bottom shelf are removed in a similar manner. When the last tray on the
bottom shelf is reached, disconnect the wire connected to the rearmost terminal of the rear battery.
Disconnect the other end of this wire, which connects to the frontmost terminal on the front battery in
the rightmost tray of the top battery shelf. Remove this last tray on the bottom shelf.
