S&C Vista - Low-Voltage Phasing Procedure

S&C Instruction Sheet 682-510 27
Operation
Low-Voltage Phasing Using Optional
VOLTAGE Indicator with Phasing
STEP 1� Clean the surface and phasing pins of the
VOLT AGE indicator of dirt and debris. See
Figure47.
STEP 2� Test the VOLTAGE indicators for proper opera-
tion by following the “Checking for Voltage Using
Optional Voltage Indicator” section on page 24. If
a VOLTAGE indicator is not operating properly,
phasing should be per formed using an alternate
method.
STEP 3� Using a high-impedance voltmeter, as shown in
Figure 48, verify voltage is present and determine
the phase-to-ground voltage for each phase of
the two ways● to be phased as follows:
(a) Set the voltmeter for volts ac.
(b)
Connect one of the test probes of the volt-
meter to the metal tank of the switchgear to
ground the voltmeter. See Figure 49.
(c)
Place the other test probe on each of the
phas ing pins, in turn, for the two ways to be
phased and measure the phase-to-ground
voltage. See Figure 47. Ac voltage range is
5-8 Vac.
(d)
If the voltage measured at each phasing pin is
greater than zero and they are equal, pro ceed
to Step 4 on page 28.
(e)
If the voltage measured at any of the phas ing
pins is zero, the phases are not ener gized and
phasing cannot be performed. If the voltages
measured are not equal, the voltmeter may
not be operating properly. Phasing should
be performed using an alternate method.
● A “way” consists of a three-phase load-interrupter switch, a three-
phase fault interrupter, a bus tap, or three sin gle-phase fault interrupters�
Figure 47� Before performing phasing, thoroughly clean the
surface and Phasing pin
�
VOLTAGE indicator
Figure 49� The test probes are connected to metal tank to
ground the voltmeter and to a Phasing pin�
Figure 48� The high-impedance voltmeter and test probes�
Set voltmeter to
Volts ac
Probe
Voltmeter
Connect probe to metal tank to ground the voltmeter
Connect other probe to Phasing Pin
Phasing Pin 1
Phasing Pin 2 Phasing Pin 3