Cutler-Hammer HWT-500, Инструкция по эксплуатации

Страница: 36 / 45

I.B. 35-557
36 of 45
GENERAL ELECTRIC MECHANISM COMPONENT TESTS
Before commencing work, refer to the Safety Information.
Switch Positions
Network protector open and set for automatic operation with the relays removed.
FUNCTION Switch – “MECH” position
I & PV Switch – AI
Supp VM Switch – CA position
PHASE switch –0 position
Single PH Test Switch – OFF
VARIAC – zero position
PHASE Volt Switch – OFF position
SUPPLY Switch – 216 or 480 position depending on network system voltage
In this test, voltage is controlled by the variable autotransformer. Before commencing the test, remove any
PYC relay and replace the shunting links (jumpers) to complete the current transformer circuits. You must
know the general breaker wiring configuration for the motor close and trip circuits. For example, you must
know whether the motor is connected phase-to-phase or phase-to-ground as well as the trip device. This
information can best be obtained from the wiring diagram of the network protector breaker under test.
For mechanical closing operations the Supply VM switch should be in the CA position and should read zero.
This the based on breakers which have the closing motor wired A-B phase to phase and the reading on the
VOLTMETER reflects voltage applied between cable terminal TA and TB. Closing values for both line-to-line
and line-to-neutral wired breakers are indicated on the charts located on page 37.
Turning the VARIAC clockwise will decrease the potential as shown on the VOLTMETER. Set the potential
for minimum voltage close of either the motor or the motor control relay. Once the value is determined and
established on the VOLTMETER, push the CLOSE push button and the breaker component or the breaker
should operate. Once the breaker has closed, the VARIAC should be set to zero.
By turning the VARIAC control knob clockwise will increase the voltage displayed on the VOLTMETER. Set
the voltage to the minimum trip level and push the Trip pushbutton. The breaker must open its contacts at the
minimum voltage level.