MOUNTING 3209211 - Caterpillar

Performing maintenance inspections with power supplied to the UPS may result in serious personal injury or death. When using an external maintenance bypass, the UPS can be fully de-energized. When using an internal maintenance bypass, the UPS is not fully de-energized. Refer to the Building System Schematic to ensure that all necessary precautions have been taken before performing any maintenance procedure. Use lock out and tag out procedures as required.
Power Down Inspection
The load of the customer may be transferred to maintenance bypass during the maintenance inspection.The customer may choose to place the load onto an internal maintenance bypass or an external maintenance bypass. In this situation, confirm that the maintenance bypass source will not be interrupted by opening the upstream disconnect that is feeding the UPS before proceeding.Note: This inspection process will require that the UPS is fully de-energized.Power Down Preparation
In preparation to powering down the UPS, the load must be isolated from the UPS system. Note: Do not proceed until the customer has authorized you to transfer the load and shut down the UPS.
Notify the customer that you will be transferring the load to maintenance bypass and powering down the UPS.
Inspect all exhaust fans for correct operation. Make a note of any fan that is not working properly.
Follow the normal operating procedure and transfer the load to the static bypass.
Close the internal maintenance bypass switch.
Open the output isolation switch.