Hitachi 152SO, Installation & Operation Manual, Page: 17 / 36

PN-152SO Switch Overload Relay
Copyright 2019 SM 5929 Rev. 23, March 2019 4-3
c. The air gap between the end of the core and the Operating relay armature should
not be reduced below 0.004 inch.
4.1.4. Internal Wiring
The internal wiring should be as shown in Figure 4-2.
4.1.5. Final Calibration
This is a test of the complete overload relay including the thermal resistor connected
across the operating relay coil.
Figure 4-2. Wiring, Facing the Front of the Relay
Final calibration should be made with the relay cover applied to give normal functioning
of the thermal resistor. After a given test the thermal resistor must be permitted to cool
before the test is repeated.
Test the relay in a circuit in accordance with Figure 4-3.
THERMAL
RESISTOR D
#1
#1
#2
#2
RELAY "A" RELAY "B"
OR
ORS
(11A)
(12A)
DC+
DC-
(11B)
(12B)
W
HV+
HV-
(11C)
(12C)
S
4C
5.
00
43
.0
0