Wacker Neuson HI750 Series, Operator'S Manual, Page: 117 / 144

ghi_tx001262gb_FM10.fm
117
HI750 Basic Troubleshooting
11.2 Machines with Gas Burners
Problem/Symptom Reason Remedy
The burner goes to lockout
after the pre-purge period
because the flame does not
ignite. Air has not been evacuated
from the gas lines. Check the gas train for leaks.
The gas valve is passing too
little gas. Adjust the gas valve.
The ignition spark is irregular
or not present. Adjust or replace the electrode.
The gas valve is faulty. Replace the gas valve.
The burner does not start when
there is a call for heat. The air pressure switch is
faulty. Replace the air pressure switch.
There is no gas, or there is
insufficient pressure in the
supply lines to activate the
optional gas pressure switch. Check the gas supply.
There is a blown buss fuse. Check / replace the fuse.
The low voltage contacts or the
low voltage relay are faulty. Check / replace the low voltage relay.
The burner does not go through
prepurge, ignition is
established, the burner fires for
2 seconds, then goes to
lockout. The air pressure switch does
not change from normally
closed to normally open
contacts. This condition exists
due to insufficient pressure in
the air tube.
Move the head towards zero (0) on the
stop gate.
The burner goes through
prepurge, ignition is
established, the burner fires for
2 seconds, then goes to
lockout. The flame rod is faulty or has
shorted to ground. Replace the flame rod.
Polarity is reversed or the earth
ground is not connected
properly. Check / rectify the wiring.
The ionization current is weak
(lower than 5 micro Amps). Replace the ionization probe.
Excessive blower noise Faulty motor bearings Replace the motor bearings.
Mounting base not secure Tighten mounting hardware.
Misaligned pulleys Adjust the alignment.
Damaged wheel Replace the wheel.
Incorrect belt tension Check belt tension.
Motor overheating Incorrect belt tension Adjust the belt tension.
Over or under voltage Check the power supply.
Fan inoperative Circuit breaker tripped Reset the circuit breaker.
Loose or disconnected wiring Check the wiring and repair as needed.
Faulty motor Replace the motor.
Broken belt Replace the belt.