Emerson Liebert MPX PEM 230/400VAC 63A MPXPEM-EHBEXZ30 User Manual

• Tamper-resistant No. 1 Torx screwdriver bit, included with MPX PEM
• No. 1 PoziDriv screwdriver bit, included with MPX PEM
• No. 1 Phillips screwdriver, field-supplied

Before beginning to assemble the Liebert MPX:

• Ensure that utility power is not connected to any module or component.
• Ensure that no equipment is connected to the MPX BRM (Branch Receptacle Module).
• Ensure that the circuit breaker on the MPX BRM is Off.

After the MPX PRC (Power Rail Chassis) has been installed in the rack, it is ready for attachment of 

an MPX PEM (Power Entry Module) and then the MPX BRMs (Branch Receptacle Modules).
Emerson strongly recommends attaching the MPX PEM first, positioning it at either end of the MPX 

PRC. The module’s position will not adversely affect operation, but placing it at the end of the chassis 

will ease cable routing and separation of power and control cables in the rack.
Proper orientation of the MPX PRC is required to allow for the best use of the top or bottom entry into 

your rack. If cables will enter through the top of the rack, be sure that the MPX PRC has the power 

bus to the right side. This will put the MPX PEM in a position where the input cord will be closest to 

the top of the rack.
If cables will enter through the bottom of the rack, be sure that the MPX PRC is oriented so that the 

power bus is to the left side. This will put the MPX PEM in a position where the input cord will be 

closest to the bottom of the rack.
To balance the loads, be sure that the installed MPX BRMs have more than one unique line 

configuration (L1-L2, L2-L3, L3-L1, L1-N, L2-N, L3-N). This will help to ensure that none of the 

phases is overloaded.
If the MPX PEM is a Variable-Capacity model, an MPX IPC (input power cord) is required. Last, an 

optional Liebert RPC (rack PDU card) can be installed.

Risk of arc flash and electric shock. Can cause equipment damage, injury or death.
This unit must be properly and securely installed on the MPX PRC (Power Rail Chassis). 

Emerson strongly recommends that the MPX PEM be installed only by an individual who has 

been properly trained and qualified to perform electrical work.
Connect only one MPX PEM (Power Entry Module) to an MPX PRC (Power Rail Chassis). 

Connecting more than one MPX PEM could cause cross-conduction. Cross-conduction can 

cause upstream overcurrent protective devices (OCPD) trip or the resulting short circuit 

current may exceed the OCPD A.I.C. ratings.
Whenever the MPX PEM is connected to power, the connectors on the bottom are energized 

with hazardous voltage. 
Connect input power only after: 
• the MPX PEM (Power Entry Module) is properly installed on the MPX PRC (Power Rail 

Chassis) 

• the  MPX  IPC

™

 (Input Power Cord) is properly connected to the MPX PEM

Connect input power to the Liebert MPX only while the MPX IPC is properly connected to the 

MPX PEM. Failure to do so may subject the user to hazardous voltages.