Table of Contents
Advertisement
4.1.6. Service Recommendations
Relays should be checked periodically in service to assure they give the desired delay
times. This may be done by obstructing the switch points, measuring the current at
which the clutch slips and noting the time it takes for the relay to function.
For accurate measurement of time for the relay to operate, about five minutes should be
allowed for the thermal resistor to cool. In no case should another operation be tried
with less than six seconds cooling time or the relay may not have sufficient motor surge
current protection.
When adjusting or working on a switch machine, apply a jumper between terminals HV+
and HV- to shunt out the thermal resistor. Of course, the jumper must be removed for
normal circuit functioning.
Switch machine clutch slippage should be maintained at approximately 13 amperes. It
the clutch slippage current is excessively low, the overload relay will not function and
might be damaged.
Relay P/N
N322522-802
N322522-001
Copyright 2019
Table 4-2. Final Calibration Values
Thermal Resistor
P/N
Nom. Ohms
N436521
.046
N398311
.030
SM 5929 Rev. 23, March 2019
PN-152SO Switch Overload Relay
Operating Time
@Amps
Sec.
@Amps
13
5
13
10
Sec.
15
3
15
6
4-5
Advertisement
Table of Contents
