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Sequence of Operation (Staged Control)
The following details the sequence of operation for the low
heat option.
1 .
Unit DDC control calls for heat.
2 .
Furnace DDC control module receives a call for heat.
3 .
High limit switch is checked for safe condition.
4 .
Proof of airflow switch is check for combustion airflow.
5 .
60 second prepurge cycle starts.
6 .
Spark ignitor is activated for 3 seconds.
7 .
Gas valve receives a command for stage 1 of heat.
8 .
Burner is ignited.
9 .
Unit DDC controller calls for stage 2 of heat.
10 .
Furnace DDC controller receives a stage 2 heat
command.
11 .
Gas valve receives a command for stage 2 of heat.
Sequence of Operation (Modulating Burner)
The following details the sequence of operation for the low
heat option.
1 .
Unit DDC controller calls for heat.
2 .
Furnace DDC control module receives a call for heat.
3 .
Furnace safety switches and DDC control are checked
for safe conditions.
4 .
45 second prepurge cycle starts. Proof of airflow switch
is checked for combustion airflows.
5 .
Spark ignitor is activated.
6 .
Gas valve receives a signal to open fully.
7 .
Burner is ignited and runs for 20 seconds in high fire.
Note: if call for heat is interrupted during this timing, the
furnace will be locked in for the 20 seconds cycle.
8 .
Gas valve and induction blower motor receives a signal
to modulate burner output to match the unit discharge air
temperature setting.
LP Conversion (Staged Furnace Only)
Convert the furnace in this unit using the liquefied petroleum
(LP) gas valve spring and burner nozzles supplied in the
for part numbers .
The LP gas valve maintains the proper manifold pressure for
LP gas. See
. The correct burner orifices are included
in the kit.
Table 17: Furnace Identification for LP Conversion
Altitude Conversion
For elevations up to 2,000 feet, rating plate input ratings apply.
For high altitudes (elevations over 2,000 ft.), contact Daikin
Parts . See
for part numbers .
Table 18: Furnace Identifications for Altitude
DANGER
Never test for gas leaks with an open flame .
It can
cause an explosion or fire resulting in property damage,
personal injury, or death. Use a commercially available
soap solution made specifically for the detection of
leaks to check all connections.
Unit Size
Staged Furnace
3 – 6 Ton Unit
300049725
7 – 15 Ton Unit
300049583
WARNING
This unit is equipped at the factory for use with natural
gas only. Conversion to LP gas requires a special kit
supplies by Daikin Parts. Failure to use the proper
conversion kit can cause fire, carbon monoxide
poisoning, explosion, personal injury, property damage,
or death.
Staged Operation
2000—2999
300049578
3000—3999
300049579
4000—4999
300049580
5000—5999
300049581
6000—6999
300049582
IM 1125-6 • REBEL ROOFTOPS 32
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