Rockwell Automation 140U Q, M Frame CB Installation and Operation for Thermal Magnetic Trip Units - Manual (Page 2)

40752-077(2) Effective 5/02
Page 2
Internal Accessories: The following types of circuit
breaker internal accessories, which mount on the
trip units, are available for use. The number of
the instruction leaflet covering the installation of the
accessory is shown.
• Alarm (Signal)/Lockout (ASL) Switch..........40752-076
• Auxiliary Switch ..........................................40752-074
• Shunt Trip....................................................40752-075
• Undervoltage Release Mechanism
(Handle Reset) ...........................................40752-070
2. INSTALLATION
There are two major differences between Q & M-Frame
Thermal Mag trip units. The M-Frame trip units have metal
tabs that prevent them from being seated into the slots in
the side-plates of the Q-Frames as described in Sec. 2-4.
Also, the M-Frame trip unit conductors have angles on
the load end, which fit within the shapes machined in the
load conductors of the M-Frame. Conversely, the Q-Frame
trip units will not seat into an M-Frame. There are projec-
tions in the base mold of the M-Frame which interfere
with the bracket of the Q-Frame trip units and the conduc-
tors will not fit within the contours of the M-Frame load
conductor.
The installation procedure consists of inspecting and
installing the trip unit. To install the trip unit, perform the
following steps.
Note: If required, internal accessory installation
should be done before the circuit breaker is mounted
and connected. Refer to individual accessory
instruction leaflets.
2-1. Make sure that the trip unit is suitable for the
intended installation by comparing nameplate infor-
mation with the existing equipment ratings and sys-
tem requirements. Make sure that you are installing
the correct type of trip unit, Q or M-Frame, in the
correct type of frame. Inspect the trip unit for com-
pleteness and check for damage before installing
it in the circuit breaker frame.
Note: Trip unit center retaining screw is captive in the
trip unit mechanism pole bracket; the outer pole
screws are supplied with the breaker frame. In the
M-frame, the load-end trip unit mounting screws
are supplied with the frame.
2-2. Remove circuit breaker pan-head cover screws and
covers.
2-3. Remove trip unit outer screws and red plastic
washers from the breaker frame. Discard red plas-
tic washers. For an M-frame, remove the
load-end trip unit mounting screws from the frame.
Note: The trip unit outer screws may be placed in the
trip unit conductor holes at this time. If preferred, a
hexagonal-head wrench may be used to position the
screws when the trip unit is in the base.
2-4. Position trip unit in base. Make sure latch bracket
pin is properly seated in slots in side plates (see
Fig. 2-1). If necessary, push circuit breaker handle
towards the closed position to help seat trip unit.