INSTALLATION AND OPERATION INSTRUCTIONS
3-4
SFC COMBI BOILERS SFC-99, SFC-125
INSTALLATION AND OPERATION INSTRUCTIONS
3-4
SFC COMBI BOILERS SFC-99, SFC-125
3.4 FUEL CONVERSION
The SFC series modulating unit is factory re-tested to operate with natural gas.
The rating plate is marked to indicate which fuel the particular unit has been set
up with. Firing a unit with a fuel other than what is listed on the rating plate is
prohibited unless the following conversion procedure is completed by a qualied
technician.
Fuel conversion requires hardware adjustments (orice replacement) as well as
measurement and possible tuning of the low re mixture. Detailed instructions
including parts and labeling are found in Fuel Conversion kits. Refer to Table 11
for the correct kit number.
NATURAL GAS PROPANE
CO
2
VALUE (%) AT HIGH FIRE WITH THE FRONT COVER OPEN
Max. CO
2
value 10.1% 11.5%
Min. CO
2
value 9.1% 9.8%
CO
2
VALUE (%) AT LOW FIRE WITH THE FRONT COVER OPEN
Max. CO
2
value = Actual value at High re
= Actual value at High re
– 0.3%
Min. CO
2
value 9.1% 9.5%
Table 12: CO
2
Values and High and Low Fire
The following procedure must be carried out by a qualied technician.
1. Ensure that the gas supply is turned off at the manual gas valve.
2. Disconnect the electrical power.
3. Disconnect the nut at the gas valve outlet (top of the gas valve) and remove
the orice and O-ring.
4. Insert the correct orice into the O-ring, and re-install into the nut at the gas
valve outlet (top of the gas valve) and then tighten the nut.
5. Restore the gas supply by opening the manual gas valve.
6. Test for leaks by using an approved leak detection solution on all joints.
7. Carefully follow the “Prior to Start-Up” – Section 3.2 and “Commissioning” –
Section 3.3 procedures on the preceeding pages 3-2 and 3-3.
DANGER
Operating any IBC unit using
a fuel other than the fuel
listed on its rating plate is
prohibited. If the information
in this section related to
conversion to alternative
fuels is not followed exactly,
a dangerous situation can
result, leading to re or
explosion, which may cause
property damage, personal
injury, or loss of life.
Figure 42: Orice and O-ring
PROPANE ORIFICE CHART
MODEL
NUMBER
ORIFICE
SIZE
SFC-99 315
SFC-125 370
NATURAL GAS ORIFICE
CHART
MODEL
NUMBER
ORIFICE
SIZE
SFC-99 392
SFC-125 450
ALTERNATIVE
NATURAL GAS ORIFICES
FOR CALORIFIC VALUES
750–900 BTU/FT
3
MODEL
NUMBER
ORIFICE
SIZE
SFC-99 426 (P-839)
SFC-125 490 (P-840)