Preliminary Calibration; Figure 4-1. Circuit For Preliminary Calibration - Hitachi 152SO Installation & Operation Manual

4.1.3. Preliminary Calibration

The Operating and Stick relays should be individually calibrated to meet the limits given
in Table 4-1. With the relays disconnected, this is no problem. If the relays are wired,
they can be calibrated by temporarily opening the thermal resistor circuit at one terminal
and testing in a circuit as shown in Table 4-1.
Relay
Operating, N398329
Stick, N398335
When calibrating the stick relay, the operating armature must
be picked up manually to close the front contact.
REAR VIEW OF PN-152SO RELAY
MOUNTING BASE
11C
DC+
HV+
HV- W DC-
12C 12B 12A
The load springs and front contact heel of the Operating relay and the front contact
spring of the Stick relay may be given a slight readjustment of their pressures if
necessary to meet the specified pick-up values.
a. Drop-Away - Each Style "L" relay shall be given a charge of four times the pick-
up value and the current, then gradually reduced until the armature drops away,
opening the front contact.
b. Pick-Up and Working - After the drop-away reading, the energizing circuit shall
be opened for one second. Then current of the same polarity shall be applied
again and gradually increased until the armature is attracted and the front contact
made. This is the Pick-Up and Working Value; and at this energization, the
armature shall move to the full stroke position.
Copyright 2019
Table 4-1. Preliminary Calibration Values
Ohms
5.0
750.0
OPER
11A
STICK

Figure 4-1. Circuit for Preliminary Calibration

SM 5929 Rev. 23, March 2019
PN-152SO Switch Overload Relay
Pick-Up and Working
Min. Drop
Away
Min.
0.20 V. 0.95 V.
0.90 V.
NOTE
S.P.D.T.
SWITCH
V
Max
1.0 V.
8.0 V.
+
_
4-2