ICP C8MPN - Main Burner Flame Check

32
441 01 2611 06
Figure 37
Manifold
25--23--51z
Some Models may vary
Figure 38
Clearances
Measure from face of orifice to the
back side of the manifold.
1.21²
1.11²
29.3 mm
+1.5
-- 1 .1
8. Reassembleallpartsinreverseorderas removed.Besureto
engagethemainburnerorificesinthe properopenings in the
burners.
9. After reassembling, turn gas on and check all joints for gas
leaks using a soapy solution. All leaks must be repaired im-
mediately.
Main Burner Flame Check
Allow the furnace to run approximately 10 minutes. Then inspect
the main burner and pilot flames. See Figure 39.
Check for the following:
· Stable and blue flames. Dust may cause orange tips or
wisps of yellow, but flames MUST NOT have solid, yellow
tips.
· Flamesextendingdirectlyfromburnerintoheatexchanger.
· Flames do NOT touch sides of heat exchanger
If any problems withmainburnerflamesarenoted, it may benec-
essary to adjust gas pressures or check for drafts.
Main Burner
Burner Face
10--10--78
Figure 39
Air Temperature Rise Check
CAUTION
!
REDUCED FURNACE LIFE HAZARD
Failure to properly set the air temperature rise may
result in reduced furnace life.
U
O
N
L
Y
t
h
b
l
t
d
t
k
d
“
Y
”
f
Use ONLY the blower motor speed taps marked “Y” for
YES for setting air temperature rise.
Blower Motor Speed Taps for
N8MPN/L and *8MPN/L Model Sizes
Model Sizes
LO
RED
MLO
BLUE
MHI
ORN
HI
BLK
050B12 N Y Y N
075B12 N Y Y Y
075F16 N N Y Y
100F14 N N Y Y
100F20 N Y Y Y
100J20 N Y Y Y
100J22 Y Y Y N
125J20 N Y Y Y
125J22+ Y Y Y Y
150J20Ö N Y Y Y
+N8MPN only Ö *8MPN only
TheblowerspeedMUSTbesettogivethecorrectairtemperature
rise through the furnace as marked on the rating plate. Tempera-
ture rise is the differencebetween supply and return airtempera-
tures.
To check temperature rise, use the following procedure:
1. Placethermometersinsupplyandreturnairregistersasclose
to furnace as possible, avoiding direct radiantheat fromheat
exchangers.
2. Operatefurnacefor10minuteswithalltheregistersandduct
dampers open by using a jumper wire on R to W thermostat
connections on the fan board.
3. Take readings and compare with range specified on rating
plate.
4. Iftheairtemperatureriseisnotinthecorrectrange,theblow-
er speed must be changed. Ahigher blower speed will lower
the temperature rise. A lower blower speed will increase the
temperature rise.
5. Removethe jumper wire aftertheadjustments are complete.