Specifications

RailCorp Infrastructure Engineering Manual – Signalling
Maintenance Manual
Electric Point Machine Westinghouse Style M70 MKIII TMG E1583
7 Diagnostic Fault Finding Charts
7.1 Fault Finding Chart 1 - Point Machine Not Operating
Fault
Most Likely
Emergency
Subsequent
Causes
Action
Action
Point machine does not
operate when control
circuit is energised
Internal contactor or N
or R relay not operating
Mechanism damaged or
jammed due to impact
Points obstructed
Check control circuitry.
Replace control relay or
contactor if necessary
If practical repair
damage. If not, replace
machine
Overload timer is
defective
Remove blockage
Local wiring to
mechanism is defective
Defective points motor
Supply failure or loose
terminations in internal
wiring
Return relay(s) and/or
contactor to workshop
for repair
Faulty toggle
mechanism or
associated motor
control switch(s)
Bridge timer contacts
Test motor operating
circuits to mechanism. If
defective run temporary
wiring
Check brushes or
replace motor if
necessary
Check supply source
and fuses. Clean and
tighten terminations
Check toggle action and
replace components or
switch(s) as required
Refurbish damaged
machine if economically
justified. If not,
cannibalise for parts
Replace timer
Replace defective
wiring
Return defective motor
to workshops for
overhaul
Version 1.0 © RailCorp 2009 Page 49 of 52
Issue Date: 1 December 2009 Uncontrolled when Printed