9. Thermal overload relay
a. Overload relay incorrectly set
a. Check and adjust. Reset relay
cuts out during operation
b. One phase of mains supply line
b. Check fuses and line terminals
for tightness. Check voltage
across motor line terminals
c. Mains supply voltage variations
c. Check generator output
exceed normal tolerances
d. Ambient temperature too high and
d. Improve ventilation of room
causes overload relay to trip
e. Motor stops and starts too frequently
e. See 5
f. Overcurrent due to motor or
f. Measure motor line current
compressor/vacuum pump failure
in the three phases. If
currents exceed rated motor
current, have compressor
inspected; if currents are
not equal, have motor
5. Valve Replacement Procedure For Air Compressor (Model 3LE6A). A faulty valve must be replaced immediately.
Serious damage will result within a short time if a unit is running with a broken valve disk. A faulty valve can be
discovered by insufficient air pressure or by a decreased vacuum. It is highly recommended to replace the valves and
gaskets each time the cylinder heads are disassembled, because a new position of old valves results in accelerated wear
and damage of the valves. The following instructions have to be faithfully followed when replacing the valve disks.
Refer to Figure 1A.
Release pressure from the unit and turn electrical power to the unit OFF before starting repair work.
Failure to comply with this warning could result in injury or death to personnel.
1. Rubber cord joint
2. Guide pin (2 off)
3. Rubber cord joint
6. Inlet valve disk
7. Valve seat
8. Outlet valve disk
9. Outlet valve guard
10. Spiral spring
11. Cylinder head cover
a. Remove oil filler cap and remove retaining cover, air filter and the cover of the air intake silencer.
b. Disconnect cylinder head cover (11) from the inlet and outlet pipe flanges. Remove cover (11).
c. Remove spring (10) outlet valve guard (9) and outlet valve disk (8).
d. Lift off valve seat (7) and remove inlet valve disk (6). Do not remove guide pins (2).
e. Remove and discard all the O-rings and rubber cord joints.