Manual Operation Functional Test; Electrical Operation Functional Test; Trip Unit Test Procedure; Arc Chute Inspection - Eaton NRX Instruction Manual

Section 7: Inspection and maintenance
Figure 61. Typical nameplate information.
RYSC303W
Insulated Case Circuit Breaker
Type RF
3000 A max.
3 Pole
50/60 Hz
Interrupting Ratings
RMS Symmetrical Ampere
Volt
240~
480~
2
Customer P.O.
1
G.O.
07
16
3
160730
4
RYSC303WMAARTLR2ZADX
Instruction manual - MN013002EN
Use in cassette RY303

Manual operation functional test

Perform the following seven steps and verify if the circuit
breaker is appropriately opened or closed as indicated by
the indicator flags on the front of the breaker (Figure 4).
Step 1: Charge the mechanism springs using charging han-
dle or motor operator.
Step 2: Press the ON pushbutton to close breaker manually.
Step 3: Charge the mechanism springs using either the
charging handle or motor operator. (If using motor opera-
tor, disconnect the power to motor to prevent automatic
recharging).
Step 4: Press the OFF pushbutton to manually open the
breaker.
Step 5: Press the ON pushbutton to manually close the
breaker.
54
Series NRX with PXR - type RF low voltage power (air) circuit breakers instruction manual MN013002ENH03 September 2016 www.eaton.com
kA
100kA
100kA
208-250 V
24 V
,V ,V
,V ,V
220-250 V
Step 6: Press the OFF pushbutton to manually open the
breaker.
Step 7: Repeat the first six steps three times.

Electrical operation functional test

This test procedure is based on the assumption that the
circuit breaker is equipped with both a shunt trip and spring
release. If one of the accessories is missing, use the
manual button to replace the accessory's function. Perform
the following seven steps and verify if the circuit breaker is
appropriately opened or closed as indicated by the indicator
flags on the front of the breaker (Figure 4).
Step 1: Charge the mechanism springs using the charging
handle or motor operator.
Step 2: Close the breaker by applying the rated voltage to
the spring release accessory.
Step 3: Charge the mechanism springs using either the
charging handle or motor operator. (If using motor operator,
disconnect power to motor prevent automatic recharging.)
Step 4: Open the breaker by applying the rated voltage to
shunt trip accessory.
Step 5: Close the breaker using the spring release acces-
sory.
Step 6: Open the breaker using the shunt trip accessory.
Step 7: Repeat the first six steps three times.

Trip unit test procedure

The trip unit may be tested via its front panel display inter-
face or through the USB connection to a PC with the Power
Xpert Protection Manager installed. Refer to the instruction
manual for series NRX PXR 20/25 for instructions on test-
ing via the display interface. For testing through the USB
interface, refer to the quick start guide for the "Power Xpert
Protection manager software" .

Arc chute inspection

When a circuit breaker experiences a high level fault, or dur-
ing regularly scheduled maintenance periods, the arc chutes
should be inspected for any kind of damage or dirt. Be
especially alert for signs of significant erosion within the arc
chute.
To remove the arc chutes and inspect both the arc chutes
and arc chambers, proceed with the following seven steps.
Step 1: (Drawout breakers) Locate the metal latches on each
side of the breaker secondary contact assembly. Rotate the
latch on one side by using a small tool to press the lower
portion of the latch and release the light grey inner cradle
which houses the accessory plugs. Push the inner cradle in
a small amount to keep the latch disengaged (inner cradle
will be angled). While holding the inner cradle in this posi-
tion, rotate the second metal latch in a similar manner.