Utility Relay Company AC-PRO-II, Instruction Manual

Page: 36 / 56

AC-PRO-II
®
Instruction Manual www.utilityrelay.com
Page 34
To test the OV trip or alarm function, a primary or secondary
injection test set, a variable voltage source, and a timer is
needed.
Make the temporary connections shown in Figure 14.4. The
maximum voltage of the variable voltage test source should
be at least 10% above the programmed OV pick-up setting.
Verify that the Phase A voltage is indicated on the display.
Reminder: voltage measurement and settings are for Line-
to-Neutral voltages (i.e. 277V is the Line-Neutral voltage on
a 480V 3-phase system).
The OV delay feature can be tested with a timer. The OV
function is definite time, so the delay remains the same
regardless of the severity of the overvoltage.
From Variable
Voltage Source
"Hot" Neutral





AC-PRO-II
VDM
Voltage
Divider
Module
A B C G





Figure 14.4: Overvoltage Test temporary
connections
Overvoltage Test Notes:
1) After an OV trip or occurs, repeated OV trips are blocked
until current is re-established.
2) If an OV alarm occurs, it is latched and must be reset
using the display and push buttons.
Overvoltage Test Procedure:
1) Apply voltage at least 10% below the OV Pickup setting.
2) No OV trip should occur.
3) Increase the voltage to at least 10% above the OV
Pickup setting and start the timer.
4) An OV trip should occur /- 0.25 seconds of the
OV time delay setting.
Although primary injection testing is the preferred method to
test an AC-PRO-II installation, secondary injection testing
can also be used.
The B-292 secondary inection test set (with blue panel) can
test both the original AC-PRO and AC-PRO-II trip units. The
B-291 secondary injection test set (with red panel) canot test
the AC-PRO-II trip unit.
Figure 15.1
: B-292 Secondary Injection Test Set
NOTE: Utility Relay Company can modify newer versions of
existing AC-PRO secondary injection test sets (with red
panel) to be compatible with AC-PRO-II trip units. Contact
Utility Relay Company for details.
Most standard relay test sets can also be used to secondary
injection test the AC-PRO-II trip unit.
The following are required:
•
24VDC Power Supply (URC Part #T-490-ASM) to power
up the AC-PRO-II trip unit so that it will accept current
•
Relay test set with a 0 to 12 Amp range
•
True RMS ammeter in the test set or externally
connected
•
Method to stop the relay test set and test set timer when
the breaker trips
Test procedure:
1. Power up the AC-PRO-II trip unit with the USB power
supply so it will accept current
2. Temporarily turn off GF.
3. Connect the output leads from the relay test set to the
Phase “A” CT terminals (it is not necessary to disconnect
the CT)
4. Proceed with pick-up and time testing of Phase “A”
5. When finished, similarly test Phase “B” & “C”
6. Turn GF on (if desired) and test by injecting current on
any one of the Phases
**** IMPORTANT ****
The CT circuits are internally grounded to the AC-PRO-II
case.
If any of the CT wires are externally grounded, the
AC-PRO-II will not read current correctly.
Some relay test sets have a grounded current output.
To secondary injection test the AC-PRO-II trip unit with this
type of test set, the AC-PRO-II trip unit must be isolated
from the test set ground.
14.11 Overvoltage (OV) Test
15.0 Secondary Injection Testing
15.1 Secondary Injection Test Set
15.2 Standard Relay Test Set