Incorrect Rotation Of Burner Motor; Motor & Fan - Removal; Burner Motor Fails To Start; Starting Flame Failure Without Ignition - Nu-Way XGN Series Handbook

Incorrect Rotation of Burner Motor

The Fan Motor rotates clockwise viewed from the
shaft end. If the motor is single phase, replace the
motor. If three phase, interchange any two phases.
Motor & Fan – Removal
Remove the control package cover and disconnect
the four gas train plugs from the MBC controller.
Remove the retaining screw securing the control
package to its mounting bracket.
Lift the complete control package from the
mounting bracket and rest it on top of the burner
casing.
All the motor securing devices will now be visible
and accessible.

Burner Motor Fails to Start

Check:
that the electrical supply is available and the
•
burner is correctly wired
all fuses for continuity and size
•
• all control instruments are "calling for heat"
the MBC control is not locked out
•
The gas supply is not isolated
•
There is sufficient gas pressure
•
The gas pressure switch is correctly set
•

Starting Flame Failure Without Ignition

Check:
The glass envelope of the IR detector is clean
•
and correctly positioned
The IR Detector sensitivity and its wiring
•
The air pressure switch is set correctly
•
The electrode is correctly set and the porce-
•
lain is not cracked
The ignition transformer is not faulty
•

Starting Flame Failure Without Flame

Check:
The air setting is correct
•
There is sufficient gas under ignition
•
conditions
Ensure that the start rate gas flow
does not exceed 30% of the high
flame gas rate as measured at the
Gas Meter.
The gas valve(s) operate correctly
•

Burner Fails to Establish Main Flame

Check:
• The gas butterfly is operating correctly
• The combustion air is set correctly
• There is sufficient gas

IR Detector Possible faults

If the LED's light up during the pre-purge phase.
Sensitivity set too high.
•
Stray light.
•
Ignition spark visible to detector (directly or
•
reflection). Correct by preventing direct sight
of ignition spark.
Interference from ignition cable (lay cables
•
some distance apart, or possibly screen the
detector).
No indication from LED's after establishment of
flame:
Incorrect or faulty wiring.
•
Sensitivity set too low.
•
Detector positioned wrongly (receives no
•
light).
Detector or viewing window dirty.
•
Defective detector.
•

6FH Error - Failure of the air servo motor

Isolate the burner from the power supply and
•
check the lead connectors at the motor and
controller for a positive location.
Disconnect the servo motor from the air
•
damper shaft. With the gas supply isolated
restart the burner and check the display runs
through the "Check servo drive" displays. If
6FH is reported, the servo motor and lead
should be replaced. Under no circumstances
attempt to dismantle the servo motor to at-
tempt repair.
Check that the air damper shaft rotates freely.
•
Check the damper blade runs clear of the
inlet casting in all positions. Check that the
bearings fitted at each end of the air damper
shaft run free and smooth. Clean and lubri-
cate the bearing surfaces with copper grease
if necessary.
XGN Handbook
Page 21