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AC Voltmeter (True RMS)
Resistor - 1500 ohms, ±10%, 25 watts
SPST switch
3.2.2. Shop Calibration Test Procedure
When performing calibration, set local voltage as specified
to within ± 1%. When checking relay calibration, current
(Amps) readings are to be used. The voltage range shown in
the table is for REFERENCE ONLY. If the current and the
voltage are measured simultaneously it is possible for one of
the readings to be out of the acceptable range. If this is the
case, as long as the current (Amps) reading is within the
specified range the relay is acceptable.
Connect the circuit shown in Figure 3-1.
1. Set switch S1 to its OFF position.
2. Connect the circuit to a 115VAC, 60 Hz isolated line.
3. Set Variac (T1) to its minimum output setting.
4. Set switch S1 to the ON position.
5. Adjust Variac T2 to obtain 115 VAC ±1% across Variac T1 as read by voltmeter
V2. This voltage must be maintained throughout this test.
6. Slowly adjust Variac T1 to increase its output until all front contacts of the relay
being calibrated just close. Record the value indicated on ammeter A; this is the
pick-up current value and should be within the pick-up current range specified in
Table 3-1.
7. Again slowly increase the output of Variac T1 until the vane in the relay just
touches the top roller. Record the value indicated on ammeter A; this is the full
stroke current value and should be within the full-stroke current range specified
in Table 3-1.
Copyright 2019
NOTE
Pick-up (PU) Current Value
Full Stroke (FS) Current Value __________________
SM 4574F, Rev. 4, March 2019
PV-250 Track Relay
__________________
3-2
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