Branch Overcurrent Protection - Vertiv MPH2 Installer/User Manual

Table 2.5 Type R Rack PDU Model Example
Descriptions
ITEM DESCRIPTION
1 Branch identification
2 Receptacle identification
3 Receptacle-status LED

2.8.5 Branch overcurrent protection

Models having greater than 20A input-current rating are equipped with branch overcurrent protection,
utilizing UL 489-listed hydraulic-magnetic circuit breakers with a flush-mount, rocker-style actuator. This
protects each receptacle group against overload and short circuits by interrupting 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
Closing Circuit Breakers
Low-profile circuit breakers are used on all rack PDU with two or three branch circuits less than 240 VAC
rating in a line-neutral configuration. Standard-profile circuit breakers are used on rack PDU with six
branch circuits or having a 240 VAC rating. Each type of circuit breaker is a rocker style as illustrated in
the following figure.
The branch circuit breaker labeling (A through F) shows which receptacles are protected by each
specific breaker. For example, receptacles on Branch A are protected by the circuit breaker labeled A.
Depending upon region and model, PDUs may also have labeling showing the phase associated with each
circuit breaker.
NOTE: The branch circuit breaker is not designed to be used as a disconnect device for the connected
load.
Figure 2.6 Circuit Breaker Branch Identification
Vertiv | Vertiv™ MPH2 Rack PDU Installer/User Guide
on page 36.)
(seeOpening and
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