Specifications

Cast Iron Series
Maintenance (Cont.)
touching the rim on both sides of the
face. The belts should be parallel to this
straight edge (see Figure 9), Dimension
A should be the same as B and Cto
ensure proper alignment of the belts.
Slots in the bed-plate allow for sliding
Troubleshooting Chart
the motor back and forth to adjust belt
MOTOR
tension. _ _ _ f f _ DRIVE
AIR COMPRESSOR
STORAGE I J \ '_= A B PULLEY
i i
If compressor is to be stored for a short , ".]_._._..
period of time, make sure that it is FLYWHEEL I
stored in a normal position and in a I STRAIGHTEDGE
cool protected area. SETSCREW C
Figure 9 - Top View
Motor hums and runs slowly or
not at all
1, Low voltage or no voltage
2. Shorted or open motor wlndin _g
3. Malfunctioning check valve or unloader valve
4. Malfunctioning pressure switch - contacts will not
close
1. Check with voltmeter, check overload relay in magnetic starter or
reset switch on motor• If overload or reset switch trips repeatedly.
find and correct the cause. See next item
2. Replace motor
3. Replace check valve or unloader valve
4. Repair or replace pressure switch
Reset mechanism cuts out
repeatedly or fuses blow
repeatedly
1. Pressure switch set too high
2. Malfunctioning check valve
3. Incorrect fuse sizeor magnetic starter heetefs
4. Malfunctioning motor
5. Loose Wiring
1. Adjust or replace
2. Clean or replace faulty valve
3. Be sure that fuses andheaters are rated properly
4. Replace motor
5. Check all electrical connections
Excessive noise in operation
1. Loose pulley flywheel belt, belt guard etc
2. Lack OTO m crankcase
3. Comlpressor floor mounting loose
4. Malfunctioning check valve
1. Tighten
2. Check for damaaan_eto bearingis, replenish oil
3. Shim to level tighten or place on islolator pads
4. Replace check valve
Milky oil in oil reservoir Water condensing in crankcase due to high humidi- Pipe air intake to less humid air source, Run pump
ty continuously for one hour
Excessiveoil consumption or oil
in air lines
Water in discharge air
1. Be sure there is a problem
2. Restricted air intake
3. Wrong oil viscosity
4. Worn iston rings
5. Oil lea_s
6, Scored o/linder
I. Excessivewater in tank
2. Hot, humid weather
I. Diagnose oil contamination roblems by testing the discharge air or
measuring oil consumption _rom the crankcase
2. Clean or replace alt filter
3. Drain oil. Refill with oil of proper visCosity
4. Replace ringss
g. Tighten bo_ts replace gaskets or o-tlngs
6. Replace c_/ nder
1. Drain tank
2. Purchase dryer
Air blowing out of inlet
Insufficient pressure
Broken first stage inlet valve (t_vo-stage unit)
Broken inlet vaFve (single stage unit)
1. Air demand too high
2. Leaks or restrictions in hosesor piping
3. Slipping belts
Replace valve assembly
1. Limit air usaoEe
2. Check for lea-ksor restriction in hose or piping
3. Tighten belts
Tank does not hold pressure 1.Worn check valve t. Replace check valve
when corno ressor isoff and
shutoff va(ve is dosed
Do not disassemble check valve
with air in tank
2, Check allconnections and fittings for tightness 2. Tighten
3. Check tank for cracks or pin holes 3. Replace tank. Never repair a damaged tank
Excessive belt wear. Light dust 1. Puney out of alignment 1. Realign motor pulley
from start is norma. Worn belts 2. Belts too tight or too loose 2. Adjust tension
separate at layers)
Tank pressure builds slowly 1. Dirty air filter 1, Clean or replace filter element
2. Blown cylinder head gasket 2. Install new gasket
3. Worn/broken intake/c_ischarge valves 3. Install new valve plate assembly
4, Air leaks 4. Tighten joints
Tan_ pressure builds up quickly Excessivewater in tank Drain tank. check speed. See Performance table
on compressor
ASME safety valve pops open 1. Wrong pressure switch setting 1, Adjust to lower pressure 175 psi maximum for two-stage unit or 135
• " psi for single stage unltI See Operation
while compressor Bsrunning 2. Malfunctioning ASME saffety valve 2. Replace ASME saTety valve
3, Pressure switch contacts welded
3. Replace pressure switch
Pressure switch continuously Malfunctioning check valve Replace the check valve if the unloader valve bleeds off constantly
blows air out the unloader valve
Pressure switch unloader valve Malfunctioning unloader valve on pressure switch Replace the pressure switch if the unit does not hiss for a short period
does not release air when the of time when the unit shuts off
unit shuts off
Interstage safety valve pops off 1. Head gasket or the gasket in the valve plate 1. Replace valve plate and gaskets
while the unit is running assembly blown
2. Valve not seating prroperly 2. Replace valve plate and gaskets
3. Maifunctlonlng safety valve 3. Replace safety valve
Interstage safety valve pops off Matfunctioning tank check valve Replace the check valve
after the unit shuts off