B E L T R E P L A C E M E N T
(Refer to Fig. 2)
Disconnect electric power and loosen motor clamping
bolts. Slide motor towards pump. If the compressor has
a totally enclosed belt guard, remove it. Remove and
replace belt(s). Hold motor against belts when retighten-
ing so the belt(s) have no more than l/2 in. (13 mm)
total play. Make certain motor is square to belts. Reinstall
guard and turn on power.
NOTE: Sometimes new belts stretch excessively after
being installed. Recheck belt tension after one
week as stated in BELTS paragraph of MAIN-
M O T O R R E P L A C E M E N T
Before replacing motor, see NOISY MOTOR and
WON'T START paragraphs in TROUBLESHOOTING
section. If motor is defective, disconnect power and
replace. Use motor of identical type, hp, voltage, speed,
and frame when reinstalling motor. Reset belt tension,
see BELTS paragraph in MAINTENANCE section.
Many motors are dual voltage and/or reversible.
Check motor's internal wiring against diagram on
motor or inside of wiring cover plate for proper
connections for voltage being used and/or rotation.
The compressor will pump air if rotated backwards
but will not cool properly.
I N T A K E A N D E X H A U S T V A L V E S ,
U N L O A D E R
Intake valves, exhaust valves and unloader mechanisms
can be disassembled for inspection, cleaning, or repair
for all compressor sizes except the l/2 hp (0.37 kW).
The l/2-hp (0.37 kW) unit has a head sealed assembly.
In the event the valves are deemed defective, replace
entire head assembly.
For the l/3-hp (0.25 kW) unit, remove the two valve
locking nuts in the head. Remove valve parts for inspec-
tion See Fig. 8 for reassembly order.
Fig. 8. Unloader for l/3-HP (0.25 kW) Unit.
The 3/4-hp (0.56 kW) and larger units have automatic
unloaders on the intake valve(s). Some preliminary
checks on unloaders are described in CIRCUIT BREAKER
TRIPS (FUSE OPENS) paragraph in TROUBLESHOOT-
ING section. The unloader for the l-hp (0.75 kW) unit
is shown in Fig. 9. All other units (3/4 hp, 0.56 kW;
l-l /2 hp, 1.1 kW; and up) use the unloader shown in
Fig. 9. Air Unloading of Intake Valves--l HP (0.75 kW).
INTAKE VALVE ASS'Y