SECTION 5
SERVICE PROCEDURES
Complete actuator disassembly is not required when performing the following service procedures.
POTENTIOMETER REPLACEMENT
1.
Run actuator to zero percent.
2.
Remove actuator from pump only if necessary for access (see Actuator Removal).
3.
Loosen potentiometer pulley setscrews.
4.
Loosen potentiometer nut.
5.
Slide out potentiometer.
6.
Unsolder wiring from potentiometer, noting orientation (refer to Figure 13). Solder new wires to new
potentiometer in correct orientation using a rosin core solder and minimum heat.
7.
Install new potentiometer in reverse sequence. At zero percent, resistance across terminals 4 and 5 should be
less than 10 ohms for a 250-ohm pot; less than 40 ohms for a 1000-ohm pot. When dual potentiometers are
used, the same resistance should be set across terminals 1 and 2. To set resistance, loosen indicator pulley
(410-D) setscrews and manually turn the potentiometer.
8.
Tighten indicator pulley setscrews. Run the actuator toward 100 percent. Resistance should be 235 ohms or
more for a 250-ohm pot; 940 ohms or more for a 1000-ohm pot.
DRIVE BELT/PULLEY/MOTOR REPLACEMENT
1.
Run actuator to zero percent.
2.
Remove actuator from pump only if necessary for access (see Actuator Removal).
3.
Remove belt clamp (280-A).
4.
Loosen pulley setscrews and remove pulleys as necessary. Replace pulleys in the same orientation to facilitate
tightening of setscrews.
5.
If motor is being replaced, remove two motor mounting nuts, lockwashers, and motor. Mark and unclip capacitor
leads and cut motor wires.
6.
Install new part, and follow previously outlined steps in reverse order.
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