What To Inspect; Functional Field Testing - Eaton Magnum Air MWN-408 User Manual

6.4

What to inspect

What to inspect and to what extent is dictated by the
nature of the maintenance function. Routine inspections
require one type of observation. Inspections following a
known high level fault require more detailed inspections.
A drawout type circuit breaker should first be withdraw
from its compartment onto the compatment's extension
rails. When the inspection is complete, the circuit
breaker can be levered to the TEST position to check the
electrical operations of the circuit breaker. During the
levering out and levering in of the circuit breaker, be
aware for any signs that would indicate that this process
is not working properly.
During the inspection of fixed type circuit breakers, bus
systems supplying the fixed circuit breakers should be
de-energized for convenience and safety.
For functional testing of the trip unit, refer to the separate
detailed instruction book dedicated to the trip unit.
Once the circuit breaker has been cleaned as described in
paragraph 6-2, visually inspect it for any signs of damage,
missing or loose parts and unusual wear. Be especially
alert for foreign matter that must be removed. On
drawout circuit breakers, inspect the primary disconnect
finger clusters for signs of wear and erosion. Make
appropriate corrections to anything found out of order.
6.4.1

Functional field testing

BEFORE DOING ANY WORK ON DRAWOUT TYPE
CIRCUIT BREAKERS, MAKE SURE THE BREAKER IS
LEVERED OUT TO THE TEST OR DISCONNECT
POSITION. DURING THE LEVERING OUT AND
LEVERING IN OF THE CIRCUIT BREAKER, BE
AWARE OF ANY SIGNS THAT WOULD INDICATE
THAT THE LEVERING PROCESS IS NOT WORKING
PROPERLY. IF WORKING ON A FIXED CIRCUIT
BREAKER, BUS SYSTEMS SHOULD BE DE-
ENERGIZED FOR CONVENIENCE AND SAFETY. THE
CIRCUIT BREAKER SHOULD BE SWITCHED TO THE
OFF POSITION AND THE MECHANISM SPRINGS
DISCHARGED.
1812.900A
CAUTION
Eaton Eaton recommends that the following functional
tests be performed on Magnum circuit breakers as part of
any maintenance procedure. The circuit breaker should
be removed from service and Eaton notified if the circuit
breaker fails to perform any of these tests successfully.
Please be prepared to provide the number of operations
the circuit breaker has to date as well as the following
nameplate information:
1
2
3
4
1. G.O.#: It: Seq:
2. Cust. P.O.:
3. Date of Manufacture
4. Cat#:
Manual Operation Functional Test
Charge the breaker mechanism springs either using the
charging handle or the motor operator. Press the ON
pushbutton to close the breaker manually and verify
closing by noting the state of the indicating flag. Charge
the breaker mechanism springs either using the charging
handle or the motor operator. If using the motor
operator, disconnect power to it to prevent automatic
recharging. Press the OFF pushbutton to manually open
the breaker. Press the ON pushbutton to manually close
the breaker. Is the breaker closed? Press the OFF
pushbutton to manually open the breaker. Is the breaker
open? Repeat this entire described test procedure three
times.
Magnum
47