Amana GUIA Series Service Instructions Manual page 141

SERVICING
NOTE: Any bending, twisting, or distortion of the electrical
tabs on the sensor will adversely affect the calibration of
the switch and result in unacceptable performance of the
sensor.
Refer to the Radiant Sense System Wiring Diagram in
GUIB/GCIB Technical Manual for details.
WARNING
Disconnect Electrical Power Supply:
1 Remove burner compartment door to gain access to
the radiant flame sensor.
2. Disconnect the wires from the Radiant Sensor.
3. Using a VOM check from common terminal to NC (Nor-
mally Closed) - should read closed. Check from Com-
mon to NO (Normally Open) - should read open.
WARNING
LINE VOLTAGE NOW PRESENT.
4. Place unit into a heating cycle.
5. Using a VOM check from chassis ground, to pin 8 FSO
(GR-9 wire) on ignition control. No power check pres-
sure switch and ignition control.
6. Within the ignitor preheat period, check from chassis
ground, to pin 12 FSI (BR-10 wire) on ignition control.
No power check BR-10 wire.
6. When the Radiant Sensor senses sufficient heat it will
close the N.O. contacts. Power should now be read at
pin 4 MV FS (VT-12 wire). No power check VT-12 wire,
replace Radiant Sensor if necessary.
7. After check and/or replacement of radiant flame sensor,
reinstall burner compartment door and verify proper unit
operation.
S-15 CHECKING MAIN BURNERS
The main burners are used to provide complete combus-
tion of various fuels in a limited space, and transfer this
heat of the burning process to the heat exchanger.
Proper ignition, combustion, and extinction are primarily due
to burner design, orifice sizing, gas pressure, primary and
secondary air, vent and proper seating of burners.
.023" - .027"
Beckett Burner
WARNING
Disconnect Gas and Electrical Power Supply:
In checking main burners, look for signs of rust, oversized
and undersized carry over ports restricted with foreign ma-
terial, etc, refer to previous drawing.
S-16 CHECKING ORIFICES
A predetermined fixed gas orifice is used in all of these
furnaces. That is an orifice which has a fixed bore and po-
sition as shown in the following drawing.
No resizing should be attempted until all factors are taken
into consideration such as inlet an manifold gas pressure,
alignment, and positioning, specific gravity and BTU con-
tent of the gas being consumed.
The only time resizing is required is when a reduction in
firing rate is required for an increase in altitude.
Orifices should be treated with care in order to prevent dam-
age. They should be removed and installed with a box-end
wrench in order to prevent distortion. In no instance should
an orifice be peened over and redrilled. This will change the
angle or deflection of the vacuum effect or entraining of pri-
mary air, which will make it difficult to adjust the flame prop-
erly. This same problem can occur if an orifice spud of a
different length is substituted.
WARNING
Disconnect Gas and Electrical Power Supply:
1. Check orifice visually for distortion and/or burrs.
2. Check orifice size with orifice sizing drills.
3. If resizing is required, a new orifice of the same physi-
cal size and angle with proper drill size opening should
be installed.
A
The length of Dimension "A" determines the angle of Gas
Stream "B".
A dent or burr will cause a severe deflection of the gas
stream.
GAS
STREAM B
DENT OR
BURR
GAS
STREAM B
141
Rev. 1