12
Midco
International
Inc.
8471 34
3. For intermittent, or interrupted ignition systems. See Figure 5a for typical piping.
a. Pipe the pilot gas supply line up stream of the main gas valve.
b. With the unit running adjust the pilot pressure regulator to 3.5 inch W.C. for natural gas
or 2.0 inch W.C. for propane gas. Using a natural gas pilot or 5
″
to 7
″
, using a propane
pilot
with
ori
fi
ce # 4957-07 (#58 Drill .042)
4. For direct spark ignition system when using a pilot for ignition. See Figure 5b.
a. Pipe the pilot gas supplied line to the main gas line downstream of the main gas valve.
5. Pilot
ignition
a. Make sure the main gas valve to the burner is closed for intermittent or interrupted
ignition.
b.
Observe
the
pilot
fl
ame, the
fl
ame should be blue and should extend approximately to
half of the burner end plate.
c.
Check
the
fl
ame signal.
d. Flame signal should be between 2-5 UA or 2-5 VDC
6. Depending on the pilot con
fi
guration make following adjustments, if required.
a. For Spark rod and
fl
ame rod con
fi
gurations
Make
sure
the
fl
ame rod is pointing towards burner manifold.
Make
sure
the
fl
ame rod is not touching ba
ffl
es or burner manifold.
Make sure the spark rod is positioned above the pilot gas tube and that it will spark to
the end of the gas tube. See Pilot Detail Drawings for this setting on page 15.
b. Spark rod and UV
Make sure the spark rod is positioned above the pilot gas tube and that it will spark to
the end of the gas tube.
7. Main burner ignition
Close the manual gas valve.
a. Set the Modulating Gas Control System to low
fi
re position.
·
Slowly open the manual gas valve.
· The
fl
ame should be evenly extending in the burner.
· The
fl
ame should be located in the casting of the burner.
· Check
the
fl
ame signal.
Close the manual gas valve.
b. Set the Modulating Gas Control System to high
fi
re position.
·
Slowly open the manual gas valve.
· Observe
the
fl
ame at high
fi
re; the
fl
ame should be blue approximately 10 to
12
″
long. If the
fl
ame is long, lazy and orange the air to fuel ratio is not correctly
adjusted . The pressure across the burner should be increased, refer to Chart 2.
· Check
the
fl
ame signal.
·
Check the manifold pressure to the corresponding
fi
ring rate. If the manifold
pressure does not correspond to the pressures shown in Chart 3. Re-adjust if
necessary.
For a high
fi
re start system the
fi
rst gas port next to the pilot might require to be blocked using
furnace cement to prevent potential pilot blow outs and
fl
ame failures. See Figure 7 - Pilot
Con
fi
guration.
Slight redness and warpage of the ba
ffl
e plates may occur at the high and intermediate
fi
re inputs.
This will not harm the burner. Once an initial discoloration and warp has taken (“set”) no further
permanent change will take place.
If the end plates redness occurs during high and intermediate
fi
re inputs, the distance between the
end plates and the pro
fi
le opening might not be su
ffi
cient for the air to cool the end plates. Pro
fi
le
readjustments might be necessary.
___________________________________
Installation
Burner Setup Continued
