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Instruction Book
IB182012EN March 2017 www.eaton.com
50DH-VR-50AXU / 50XU / 75U / 75ARU - 600 / 1200A
Replacement Circuit Breaker
SECTION 5: INSPECTION & INSTALLATION
DANGER
BEFORE PLACING THE CIRCUIT BREAKER IN SERVICE, CAREFULLY FOLLOW
THE INSTALLATION PROCEDURE BELOW AND THE SAFE PRACTICES SET
FORTH IN SECTION 2. NOT FOLLOWING THE PROCEDURE MAY RESULT IN
INCORRECT CIRCUIT BREAKER OPERATION LEADING TO DEATH, BODILY
INJURY, AND PROPERTY DAMAGE.
When the circuit breaker is first commissioned into service and each
time the circuit breaker is returned to service, it should be carefully
examined and checked to make sure it is operating correctly.
5.1 EXAMINATION FOR DAMAGE
Examine the circuit breaker for loose or obviously damaged parts.
Never attempt to install nor operate a damaged circuit breaker.
5.1.1 NAMEPLATE VERIFICATION
Verify the information on the new VR-Series nameplate matches the
information on the purchase order. If any discrepancies exist, notify
Eaton for resolution prior to proceeding.
5.2 CELL MODIFICATIONS
The width of the VCP-TR vacuum replacement element is wider
than the original 50-DH air magnetic front racked or rear racked
circuit breaker. Internal channels midway back in the circuit breaker
compartment must be modified to allow clearance for the 50-DH-
VR circuit breaker. Approximately one-half inch of steel must be
removed from each channel. The elevation and length of removal
for the front racked replacement circuit breaker is different than the
elevation and length of removal for the rear racked replacement
circuit breaker; refer to the correct drawing for dimensional details.
If it is necessary to re-install the original air circuit breaker into the
circuit breaker compartment, these modifications do not affect the
operation of the original circuit breaker.
DANGER
BEFORE ANY MODIFICATIONS ARE PERFORMED, THE SWITCHGEAR
MUST BE DE-ENERGIZED. FAILURE TO VERIFY THIS COULD RESULT IN
EQUIPMENT DAMAGE, PERSONNEL INJURY, OR DEATH.
5.2.1 CELL CLEARANCE MODIFICATIONS FOR
50-DH-VR-50AXU & 75U (FRONT RACKING)
Follow this procedure for cell modification:
1. Before starting any modifications, confirm that the switchgear
primary and secondary circuits are completely de-energized.
2. Protect all primary disconnects and secondary disconnects and
terminal boards from the metallic dust that will be generated
during the cutting process. This must be done with drop cloths
or tarps that are sealed along their edges with duct tape or
equivalent means.
3. Refer to Figure 5.2 for dimensional information on the Front
Racked circuit breakers.
4. With a suitable marker, outline the material to be removed
according to the appropriate diagram. Put on the appropriate
personal protective equipment including safety glasses or a
shield, hearing protection, and gloves.
5. Using a power saw with a metal cutting blade, remove the metal
within the outline. A grinder may be needed to clean up the
cuts after grinding.
6. With an industrial vacuum cleaner, remove all of the metallic
dust from inside the cell. Wipe down any areas that may trap
these metallic particles, taking care not to be cut by any sharp
edges or metal burrs. Gray primer paint may be optionally
applied to the exposed metal surfaces.
7. Remove the drop cloths or tarps used to protect the primary
and secondary circuits. Carefully inspect these areas to ensure
that no metallic dust has penetrated these areas. It may be
necessary to manually operate the shutter to inspect the primary
connections. If dust is observed, remove it with the industrial
vacuum cleaner. The insulation on the primary bottles may also
be cleaned with isopropyl alcohol and a soft cloth.
DANGER
FAILURE TO COMPLETELY REMOVE METALLIC DUST COULD NEGATIVELY
AFFECT THE OPERATION OF THE CIRCUIT BREAKER AND / OR
SWITCHGEAR STRUCTURE. THIS COULD RESULT IN EQUIPMENT DAMAGE,
PERSONNEL INJURY, OR DEATH.
8. Verify that enough metal has been removed by slowly racking
the new 50-DH-VR circuit breaker to the “TEST” position.
Adequate clearance should be available on each side of the
circuit breaker such that it does not contact the steel channels.
If contact is observed, this process must be repeated to remove
enough metal to allow the circuit breaker to be installed.
9. See Figure 5.2 for channel modifications for front racking circuit
breakers.
10. After these modifications, the new circuit breaker front cover
will align with the channels on each side to conceal the channel
modifications and create the dead front barrier required for
metal-clad construction.
Figure 5.1. Completed Cell Modification (Front Racking)
