TERASAKI AME Series, Instruction Manual

Page: 29 / 40

KRB-5200h
-23-
5.2.2 Tests with Current Applied to the OCR Test Terminal
The secondary current calculated with the primary current and ACB main circuit CT ratio (I
CT
) is
applied to the OCR test terminal on the left side of the ACB to check for the tripping characteristics.
Caution

OCR field tests must be performed by competent persons.

Never touch the live terminal parts.
Otherwise, electric shock may result.

For testing of characteristic by injection to terminal: Ka, Kb, Kc, l, injection current should
be cut off immediately after OCR is operated.
Fig. 14
Test Arrangement (example) and Connections

The test current must be sinusoidal current with no distortion.

If the ACB trips open during the test, turn off the power immediately.

The OCR adapter shown in Fig. 14 is optional. This adapter should be used as a current
conversion device.
Caution : Be sure not to open the secondary side of the OCR adapter while applying the test
current. Doing so will generate a high dangerous voltage between terminals.
Before performing the tests:

Remove the XMD4M motor operator when it is mounted on the ACB. The XMD4M motor
operator is a hinged type.
For procedures for removing and mounting the operator, see
[3] Before and After Checking the
Trip Settings , XMD Series Motor Operator - Operating Instructions.

Apply voltage between auxiliary circuit terminals U
1
and U
2
when the UVT is used.
How to test the OCR:
①
Stop the generator and open a disconnector or the like to isolate all sources of power/voltage
from both the primary and auxiliary circuits.
②
Connect a power supply to the OCR test terminals

and Ka for R-phase test,

and Kb for
S-phase test, and

and Kc for T-phase test.
③
Calculate the test current.
The main circuit CT ratio (I
CT
), generator rated current (In), and trip pick-up current (I
1
or I
2
) are
shown on the OCR nameplate.
ACB
ANS1S OCR adapter
5A / 50mA CT
* Resistor
* Voltage
regulator Power source
50/60 Hz
* Power
switch
* AC ammeter
OCR test terminal
(Devices marked with *
are not supplied.)
Test current switch
(AUX SW of breaker)
Connect to test pole (Ka, Kb,
Kc) and field test terminal
l
.
mA