Operator's Manual

Page 50 Troubleshooting
Brake Troubleshooting
Most brake malfunctions that cannot be corrected by
synchronization or by normal brake adjustments can
usually be traced to electrical system failure.
Mechanical causes should be obvious, such as bent or
broken parts, worn linings or magnets, seized lever arms
or shoes, scored drums, or loose parts.
Electrical Troubleshooting
Start all electrical troubleshooting procedures at the
controller. Brake jerkiness or malfunction can usually be
traced to the controller. Refer to the Maintenance
Instructions section of this manual for proper adjustment
and testing procedures. Refer to the Setup Manual for
wiring diagrams.
If the voltage and amperage is still not satisfactory after
adjusting the controller, troubleshoot the connector and
then the individual magnets to isolate the problem source.
A voltmeter and ammeter are essential tools for
troubleshooting the electric brakes.
Low Voltage or Amperage
The most common electrical problem for the brakes is
low or no voltage or amperage. This is usually caused by:
• poor electrical connections
• open circuits
• insufficient wire size
• broken wires
• improperly functioning controllers or resistors
Short Circuits
Another common electrical problem is short circuits or
partial short circuits, which are indicated by an
abnormally high system amperage. Possible causes
include:
• shorted magnet coils
• defective controllers
• bare wires contacting a grounded object
Short circuits must be isolated and can be difficult to
find. If the high amperage reading drops to zero by
unplugging the MH-400, then the short is in the MH-400
wiring. If the amperage reading remains high with all the
brakes magnets disconnected, the short is in the MH-400
wiring.
Brake Troubleshooting Table
Symptom Cause
Open circuits
Severe under adjustment
Faulty controller
No brakes
Short in the circuit
Grease or oil on magnets or linings
Corroded connections
Worn linings or magnets
Scored or grooved brake drums
Improper synchronization
Weak brakes
Under adjustment