BECKWITH ELECTRIC M-3425A, Инструкция, Страница: 322 / 482

6–35
Testing – 6
50N Instantaneous Neutral Overcurrent
VOLTAGE INPUTS:
None
CURRENT INPUTS:
As described
TEST SETTINGS:
Pickup P Amps (0.1 to 240.0)
1 Amp CT Rating (0.1 to 48.0)
Time Delay D Cycles (1 to 8160)
Programmed Outputs Z OUT (1 to 8)
Expanded I/O (9 to 23)

NOTE
: Although no voltage input is required for the testing of the 50N function, it is suggested that Nominal
Volts be applied to restrain the functions which use both voltage and current inputs for operation.
Test Setup:
1. Determine the Function 50N Instantaneous Neutral Overcurrent settings to be tested.
2. Enter the Function 50N Instantaneous Neutral Overcurrent settings to be tested utilizing either the
HMI or IPScom
® Communications Software.
3. Disable all other functions prior to testing. Refer to Section 4.4 System Setpoints, for details that
describe disabling/enabling functions.
Pickup Test
:
1. Press and hold the
TARGET RESET
pushbutton, then slowly increase Current Input I
N
(terminals
53 and 52) until the
NEUTRAL O/C 50N/51N
LED illuminates, or the pickup indicator illuminates on
the IPScom Function Status screen.
The current level of operation will be (
P
) amps ±0.1 amps or ±3%.
2. Release the
TARGET RESET
pushbutton.
3. Decrease Current Input I
N
. The
OUTPUT
LED(s) will extinguish.
4. Press the
TARGET RESET
pushbutton to reset targets.
Time Test
:
1. Connect a timer to output contacts
(Z)
so that the timer stops timing when the contacts
(Z)
close.
2. Apply approximately 110% of
P
amps to Current Input I
N
(terminals 53 and 52) and start timing. The
operating time will be
D
cycles ±1 Cycle or ±1%.
3. Reduce Current Input I
N
to 0 amps.