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Revision B December 2013
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2. DC Motors
Motors should be serviced periodically to ensure good performance. Service as follows:
A. Remove head assembly from motor.
B. Check sleeve bearing in head assembly for wear.
C. Place a few drops of oil on felt liner in head assembly.
D. Check brushes for wear and replace if necessary.
E. Blow dirt and dust out of motor housing and check for shorts, burnt wires, or open
circuits in the field coil assembly.
F. Check armature and commutator for shorts or open circuits.
G. Check ball bearing on motor shaft: A growling motor can be caused by bad bearings.
H. Check for excessive “end play” of armature and add thrust washers as necessary.
I. If there is an excessive amount of water, condensation, or rust in the motor, a small
drain hole may be drilled in the motor case on the low side of the motor depending on
the mounting – consult with pump manufacturer for additional information.
Note
: A motor which does not turn in freezing weather could be caused by water that
has frozen inside the housing.
J. Be sure to check orientation of motor before replacing.
K. If motor fails to turn the pump, check the pump by turning drive shaft by hand – it may be
“set-up.”
3. Electrical Switches
A. Push button, toggle, rocker, or manual motor start switches: Defective switches are a
common cause of electrical malfunction. What SEEMS to be a serious system defect
can often be caused simply by a faulty switch, especially where the switch controls two
functions (e.g. start the motor and shift a valve) in those cases, one half the switch might
be defective, while the other half operates correctly and the fault appears to be with
some other component. Trouble shooting can be done by any one of three methods.
1. Use a continuity light to test switch. (See Test Equipment section)
2. Use a circuit test light to test switch. (See Test Equipment section)
3. Remove the wires from the switch and touch them together in the proper order to
operate them.
Note:
Even though external switch is ''waterproof'', any switch controls subject to the
weather should be mounted so that the cord exits from the bottom to prevent water from
entering the box.
B. Motor start solenoid switches: Although there may be exceptions, most solenoid
switches found on TMA pumps are the following type:
Three Post Solenoid Switch (See Figure below)
1. This three post solenoid switch is wired and constructed as follows:
[a] The large post marked ''Bat'' must be attached to the cable leading from the battery.
[b] The small post connects to the control circuit. (Push button, rocker, or toggle, etc.)
[c] The shared ''hot'' lead from the control circuit must also be attached to the large post
marked ''Bat''.
[d] The remaining large post attaches to the cable leading to the motor.
