46
7.0 Difficulty
7.3 Replacing the Electronics Unit
The UPS allows replacement of a failed Electronics Unit without interruption of
power to the load. The Isolation Unit is capable of autonomous operation and
provides power to the load isolated from EMI/RFI noise and surges.
To replace a failed EU, follow the procedures listed below.
7.3.1 Put the UPS into the bypass mode of operation by actuating the manual bypass
switch at the rear of the EU. Note: Transfers to bypass mode using the manual bypass
switch occur within 10 mS typically. The transfer back from the bypass mode occurs
in 0 mS.
7.3.2 Using a coin or large flat blade screwdriver, unscrew the EU separating screw
and pull back.
7.3.3 Using a phillips screwdriver, loosen the Battery Pack coupler lock at the rear of
the EU and disconnect the pack coupler. Disconnect the Battery Pack communica-
tions cable from the jack at the rear of the EU.
7.3.4 If necessary, disconnect cables connected at the Computer Interface port and
the Emergency Power Off interface.
7.3.5 Grasp the EU at the slots shown in the illustration and pull straight up and
away from the IU.
7.3.6 Follow the above procedures in reverse to install the replacement EU. Once the
replacement EU is installed, press any key to regain control of the UPS.
Note: Do not grasp the EU by
the display and control
panel.