DPS 016–028 Sequence of Operation
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.
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 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 limits switch(s) are checked for safe conditions.
4 .
Proof of air flow switch is checked for combustion
induced draft airflow.
5 .
30 second pre-purge cycle starts.
6 .
Spark ignitor is activated for 3 seconds.
7 .
Gas valve receives a command for stage 1 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.
Modulating 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 limits switch(s) are checked for safe conditions.
4 .
Proof of air flow switch is checked for combustion
induced draft airflow. Combustion draft inducer fan will be
operating at high speed.
5 .
30 second pre-purge cycle starts.
6 .
Spark ignitor is activated for 3 seconds.
7 .
Gas safety shut-off valve is opened.
8 .
Gas modulating valve is run to 66% open.
9 .
Burner is ignited.
10 .
Gas modulating valve remains at 66% open for 30
seconds.
11 .
After 30 seconds have elapsed, modulating controller
opens and closes gas control valves as required based
on heat input requirement from Unit DDC control.
12 .
Unit DDC control input for 8–30% of span will result in
heat input up to 30% of full heating capacity. The gas
train with the modulating valve will be used to achieve
the heating during this phase. Combustion draft inducer
fan will be operating at low speed.
13 .
Unit DDC control input for 30–55% of span will result in
heat input up to 50% of full heating capacity. The gas
train with the modulating valve will be used to achieve
the heating during this phase. Combustion draft inducer
fan will be operating at high speed.
14 .
Unit DDC control input for 55–75% of span will result in
heat input up to 75% of full heating capacity. The gas
train with the modulating valve will be used to achieve
the heating during this phase. The gas train with the
two stage gas safety valve will be used to achieve the
heating during this phase. Stage 1 coil of the two stage
gas safety will be energized. Combustion draft inducer
fan will be operating at high speed.
15 .
Unit DDC control input for 75–100% of span will result in
heat input up to 100% of full heating capacity. The gas
train with the modulating valve will be used to achieve the
heating during this phase. The gas train with the 2 stage
gas safety valve will be used to achieve the heating during
this phase. Stage 1 coil and Stage 2 coil of the two stage
gas safety will be energized. Combustion draft inducer fan
will be operating at high speed.
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www.DaikinApplied.com
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IM 1125-7 • REBEL ROOFTOPS
Содержание DPS005
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