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Troubleshooting
313937A
19
Logic Circuit
Pumps remain in forward position
and will not return
Proximity switch not sensing the trip
plate. Switch roller position may
need adjusting.
If proximity switch is working prop-
erly, the lamp will illuminate.
Proximity switch faulty.
If lamp does not work, adjust the
proximity switch by loosening the
mount screws and adjust to 0.062 in.
from the trip plate.
If the lamp still does not work, con-
tact Technical Service or replace.
4-way air cylinder directional control
valve needs servicing or replace-
ment
If proximity switch does not return
the pumps, check the signal through
to the 4-way valve. If ok, then the
4-way valve may be at fault.
Pumps remain at rest in rear position
and do not move when the machine
is signaled to start.
The Start device
Check for incoming and outgoing air
flow. Check that signal comes out of
starting device when machine is sig-
naled to start. If not, starting device
is faulty.
4-way air cylinder directional control
valve needs servicing or replace-
ment
If main input air signal comes from
the starting device, then the 4-way
control valve is not changing over.
Remove and service. (Ask for Tech-
nical Service)
Main signal not coming from rear air
cylinder pilot valve.
Check main air input to this valve. If
ok, then air cylinder valve is suspect
and requires servicing.
Material cured on piston rod.
Clean piston rod, and apply mesa-
moll.
Pump air cylinder erratic/will not fin-
ish stroke.
Input air pressure to machine
exceeds 110 psi.
Place air regulator in supply line to
machine.
Motionless Mixer (after satisfactory startup)
Patch or uncured spot in mixed
material
Pumps not starting together (phas-
ing)
See Pumping troubleshooting.
Check phasing.
Ratio off.
Perform Ratio Check procedures.
Partially unmixed material through
cycle
Mixer not clean or free
Dismantle and clean or replace.
Material leaks past inlet valves of
dispense valve, mixing block, or dis-
pense block
Inlet valve o-ring or seals damaged
or worn.
Replace o-rings or seals.
Problem
Cause
Solution
Summary of Contents for Pneumatic PR70
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