Owners manual

Introduction

Emerson

MPH2

™

Branch Overcurrent Protection

Models having more than 16A input current rating are equipped with branch overcurrent protection.

This protects each outlet group against overload and short circuit. The branch circuit breaker is a

UL 489-listed breaker with a flush-mount, rocker-style actuator. The circuit breaker interrupts the

fault current flowing in the line-to-line, line-to-neutral and line-to-PE conductors of the branch

circuits. The branch circuit breaker ratings apply over the full rated operating temperature and

frequency.

The flush-mount breakers guard against accidental trips that could interrupt power to the connected

load. Manually tripping a breaker requires a small, flat blade, such as a screw driver (see Figure 29).

Low-profile circuit breakers are used on all MPH2 rack PDU’s with two or three branch circuits less

than 240V rating in a line-neutral configuration. Standard-profile circuit breakers are used on MPH2

rack PDU’s with six branch circuits or have a 240VAC rating. Each type of circuit breaker is a rocker

style (see Figure 29).

The branch circuit breaker labeling (A, B, C and so on) shows which outlets are protected by each

specific breaker. Outlets on Branch A are protected by the circuit breaker labeled A. Three-phase

PDU’s may also have labeling showing the phase associated with each circuit breaker.

Figure 6 Circuit breaker branch identification

1.3.5 Hard-Wired Connection Features

Emerson’s MPH2 rack PDU may be equipped with either a factory-installed input power cord or

hard-wired connections. The hard-wired connection will be at one end of the unit. A terminal block in

the hard-wired connection compartment is coded to aid in making the connections. A collar secures

the input wire, keeping the strain off the terminal block connections. See Figure 7.

NOTE

The branch circuit breaker is not designed to be used as a disconnect device for the connected

load.

Branch Circuit Breakers

Standard Profile

Branch Identification

Branch Circuit Breakers

Low Profile

Branch Identification