27Tn Third-Harmonic Undervoltage, Neutral - BECKWITH ELECTRIC M-3425 Instruction Book

M-3425 Instruction Book
27TN Third-Harmonic Undervoltage, Neutral (#1 or #2)
VOLTAGE INPUTS: Configuration V2
CURRENT INPUTS: None
TEST SETTINGS: Pickup
NOTE: If 27TN #1 and 27 #2 have different pickup settings, it would be efficient to disable the one
with the higher setting first and test the lower setting operation. The higher setting operation could
then be tested without disabling the lower setting.
1. Disable functions as shown. See Section 3.2, Initial Setup Procedure/Settings, Configure Relay
Data for procedure.
2. Confirm settings to be tested.
3. Connect inputs in Configuration V2 designated above. See Section 6.1, Equipment/Test Setup for
configuration. Set at Nominal Voltage.
4. Pickup Test : Hold the TARGET RESET button in and slowly decrease the neutral voltage until
27TN/64S 100% STATOR GND LED light goes on (or the pickup indicator operates on the
computer target screen). The voltage level should be equal to P volts ±0.15 V or ±1%. Release
the TARGET RESET button and increase the input to the nominal voltage and the OUTPUT LEDs
will go out. Press TARGET RESET button to remove targets.
5. Time Test : With output contacts (Z) connected to stop the timer, apply approximately (P – 1)
volts and start timing. The contacts will close after D cycles within ±1 cycle or "1%.
6. If testing is complete, enable any functions disabled for this test. If other tests are to be
completed, check the proper functions to disable for the next test and proceed from this
configuration.
6–22
Time Delay
Undervoltage Inhibit
Programmed Outputs
Function 27TN (#1 or #2)
Functions 27, 32
P Volts (0.3 to 20.0)
Y cycles (1 to 8160)
Volts (5 to 180)
Z OUT ( 1 to 8)
Disable
Disable