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5-2.
CORRECTIVE MAINTENANCE
A. Troubleshooting
The Troubleshooting Chart (Chart 5-1) is provided to assist repair personnel when troubleshooting a siren
malfunction. This section also includes diagrams that may be helpful if the siren or control devices need repair.
WARNING
Moving parts could cause severe cuts or amputation. DO NOT rotate the commutator by
sticking your fingers in the stator ports and pushing on any part of the rotor.
B. Model 2 Motor Brush Replacement
1. Loosen the clips that hold the siren housing to the mounting surface. Lift off the housing.
2. Remove the insulated cap from the Armature Brush Holder and slide out the worn armature brush. Do not
loosen or remove the brush holder.
3. Install the replacement brush and replace the cap. Ensure that the brush is properly seated as indicated in
figure 5-1, before tightening the cap. Make sure that the cap seats properly. However, do not tighten the cap
excessively, or it may break.
C. Model 2 Armature and Field Replacement
1. Armature
(a) Turn off the power to the siren at the disconnect switch.
(b) Remove the siren
housing from the mechanism.
(c) Disconnect the electrical power wiring from
the siren motor.
(d) Remove the mechanism from the mounting surface. If desired, the legs can also be removed from
the mechanism.
(e) Remove the four bolts holding the chopper rotor and armature to the stator. Lift out the rotor and
armature.
(f) Remove the lock nut and lock washer from the armature.
(g) Use a bearing puller to pull both roller bearings from the armature shaft.
(h) Use a hydraulic press to separate the armature from the chopper rotor.
(i) When installing a new
armature it
may be necessary to change the electrical connections of the
field. Therefore, refer to the instructions included with the replacement armature for the correct field
connections.
(j) Install the replacement armature and reinstall the siren following steps (a) through (h) in reverse.
