Laars FTCF140 - Page 40

Page 40
4.13 Natural Gas to Propane Conversion (continued)
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Document 4290C
The FT Series, Floor-Standing, Gas Conversion Kit
pg 3 of 4
Manifold pressure
Gas Type ‘NG’ Gas Type ‘LP’
2" VENT 3" VENT 2" VENT 3" VENT
FTCF140
MAX Fire
-0.15
"
WC -0.216
"
WC -0.15
"
WC -0.216
"
WC
MIN Fire
0
”
WC 0.002
”
WC 0.1
”
WC 0.079
”
WC
FTCF199
MAX Fire
-0.134
”
WC -0.173
”
WC
MIN Fire
-0.015
”
WC -0.015
”
WC
Figure D
15.
Setup your combustion Analyzer and
place the sensor into the combustion test port.
16.
Per Table B for Max Fire
,
change dip switch 6 to ON and 7 to OFF.
The unit will cycle up to MAX  re.
17.
WAIT for your combustion Analyzer to stabilize. This may take up to 3 minutes depending on your combustion
Analyzer. Then check the CO
2
measurement for MAX  re. Refer to Table D for acceptable MAX  re
combustion readings. At this point, just record the CO
2
readings at MAX Fire. Do NOT attempt to adjust
CO
2
at MAX Fire. ONLY in MIN Fire, so...
18.
Per Table B for MIN Fire
,
change dip switch 6 to OFF and 7 to ON. The unit will cycle down to MIN Fire.
19.
WAIT for your combustion Analyzer to stabilize. Then check the CO
2
measurement at MIN  re. Refer to
Table D for acceptable MIN  re combustion readings.
20.
If CO
2
readings in Max Fire and MIN  re are acceptable, then skip ahead to Step 23. If not, then open the
Gas Valve Adjustment Port by removing the cap screw with a 4mm Allen wrench. See Figure E.
21.
Then use the 4 mm Allen wrench to make a minor adjustment (1/8 turn) to either increase or decrease CO
2
.
Table B DIP Switch Settings
Photo shows a model
140 using 3" venting
and natural gas.
MBH 140 199
ON OFF
MIN Fire Normal Operation
MAX Fire Normal Operation
NG Natural LP Propane
3” Vent Size
2” Vent Size
ON OFF ON ON
ON OFF OFF ON
OFF ON ON ON
REFERENCE
ONLY.
CO
2
value
Gas Type ‘NG’ Gas Type ‘LP’
2" VENT 3" VENT 2" VENT 3" VENT
FTCF140
MAX Fire 8.5~10.5% 9.5~11 %
MIN Fire 8~10% 9~10.5 %
FTCF199
MAX Fire 8.5~10.0% 9.5~11 %
MIN Fire 8~10% 9~10.5 %
Table C
Table D