GE Industrial Solutions EntelliGuard G - Manual (Page 13)

DEH-41304C EntelliGuard® G Circuit Breaker
13 March 14 Section 3 – Lifting, Mounting and Installation
©2012 General Electric All Rights Reserved 13
 Fixed portion: consists of a main fixed contact which is
brazed to a conductive pad, and arc runner which is
fastened to the conductive pad which guides the arc to
the arc chamber.
Each pole has an arc chamber comprised of arc chamber
molds which houses the de-ion plates and filtering system.
The pole configuration depends upon the breaker frame
size. For larger frames, the two pole units are connected
mechanically in parallel to form one phase.
The operating mechanism is mounted on the front housing.
The energy stored in the mechanism is used to close the
contact system. The mechanism is coupled to each pole by
a common layshaft/drive shaft.
The global trip unit measures CT current and compares the
output with set parameters. It gives a trip command during
overload and short circuit to trip the breaker within a
specified time, circuit monitors the current passing through
the circuit breaker and keeps a history of faults.
The fascia has interface buttons and features for safety
locks.
The cassette, which is used for drawout breakers, consists
of a mechanism which enables the circuit breaker to be
racked in and out, and houses the interlocks.
The front panel on the cassette has three markings which
indicate whether the breaker is in the CONNECTED, TEST or
DISCONNECTED position.
LIFTING AND MOUNTING
Using a Lifting Truck
Circuit breaker removal can be made easier by using a
specifically-designed lifting truck (Fig. 3.4). Contact the
nearest sales office for availability.
Figure 3.4. Lifting Truck
Drawout Cassette Lifting, Mounting and Installation
1. Place the cassette on a rigid, leveled appropriate
support on the switchboard. If a handling truck or
other lifting gear is used, install four. M10 lifting bolts
on to the M10 nuts available on the cassette channels
as shown in Fig. 3.5. Use all four lifting bolts at front
and rear of the cassette.
Figure 3.5. Cassette Lifting
A
A Lifting eyes
2. Mount the cassette on to the switch board using six M8
bolts, nuts and lock washers through the mounting
holes shown in Fig. 3.6. Do not tighten.
3. Ensure the cassette side walls are square to the switch
board.
4. Tighten the mounting bolts to a torque of 25 N m at
the front and rear mounting points (Fig. 3.6).
Figure 3.6. Cassette Mounting
A A
Left Right
A M8 bolts
5. Ensure there is minimal deflection/stress to the back of
the cassette when connecting busbars.
6. Connect the incoming and outgoing cables/busbars.
7. Ensure any safety shutters move freely after the
cassette is installed.
Drawout Circuit Breaker Installation into the Cassette
1. Pull the lifting handles on both side walls of the circuit
breaker.
2. Attach the lifting bar between the two holes of the lifting
eyes as shown in Fig. 3.7.