Applied Air GAS-FIRED HEATERS, Installation & Operation Instruction

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Heat is Enabled By The Following:
MDT And MRT Standard:
To enable the heat, rotate the “Temperature Setpoint”
knob (MP-15) clockwise to the desired setpoint above
the actual air temperature. The allowable temperature
range is 55° to 90°F.
MRT-PRO With Smart Room Sensor:
To enable the heat, press the “Warmer” or “Cooler”
button on the face of the remote MRT-Pro room sensor
(TS-02) to the desired room setpoint. Each push of the
button changes the temperature setpoint by 1°F. The
setpoint can be changed a maximum of + 10°F from the
default of 65°F.
Changing the heating setpoint also
changes the cooling setpoint.
MRT Expert or MDT Expert With a BACview (KP-01):
To enable the heat for MRT Expert scroll through the
“Setpoints” menu in the BACview and enter the desired
room Heating Occupied and Unoccupied Setpoints. For
VDT Expert enter the desired Heating Discharge Air
Setpoint.
Energy Savings Modes:
There are three (3) Energy Savings Modes that
could disable the burner.
NOTE: A BACview or PC is required to change
Setpoints. For a more detailed control sequence,
see the Digital Control System Users Manual.
Sequence and Burner Setup with DDC
The I/O Zone 583 Controller (UC-01) must be calling for
the burner to be enabled. The DO-2 light will be on and
Burner Enable Relay (RE-28) needs to be energized.
If the outside or inlet air temperature is above the
Heating Economizer Setpoint 65°F the burner will
be disabled.
You will need to disconnect the plug where
the Outside or Inlet Air Temperature Sensor (TS-01) and
Discharge Air Temperature Sensor (TS-03) are wired
to the I/O Zone 583 Controller (UC-01). Reconnect the
plug if you are getting close to the Freezestat lockout
time, which is approximately 3 minutes. To reset the
Freezestat alarm, simply turn the power off and back on
at the disconnect switch.
NOTE: A BACview or PC is required to change
settings. See the Digital Control System User
Manual for a more detailed sequence of operation.
Setting the Pilot Flame
CAUTION: Do not attempt to start the pilot when
furnace is full of vapor or combustion chamber is
very hot.
CAUTION: At no time should you stand in front of
the relief door.
Honeywell Flame Safeguard Control (RE-02):
A keyboard display module (Honeywell #S7800A1142)
is recommended to read the fl ame signal, and is a good
troubleshooting device. A V.O.M. can also be used on
the D.C. voltage test jacks marked “+” and “-“ on fl ame
amplifi er.
Connect manometer to pilot test tee (if applicable).
CAUTION: You will have approximately three
(3) minutes before the unit shuts down on
Freezestat (Low Discharge Temperature, if you have
disconnected plug wires TS-01 and TS-03).
Enable the fan and heat as described earlier in this
section. Check rotation of burner and induced draft
fans, amps, and overload settings. Make sure the
damper on the induced draft fan is approximately
75% open.
If limits and all safety controls are closed, the burner and
induced draft fan will run for 90 seconds before ignition
trial as a pre-purge cycle.
NOTE: Do not leave the Run/Test switch on the
fl ame safeguard relay (RE-02) in the TEST position
during P.F.E.P. for more than 60 seconds. This could
cause the control program to go into a burner status
alarm. You can recycle the power to the unit to reset
the burner status alarm.
NOTE: Pilot regulator adjustment may be needed if
the adjustment of the needle valve does not yield
the required reading. Typical adjustment of the
needle valve is 1-1/2 to 2 turns open.
NOTE: Frequently the cause of pilot problems
relates to gas pressures that are too high and/or air
dampers that are closed too far. This causes a fuel
rich mixture.
NOTE: 3 or 4 TRIALS MAY BE NEEDED TO PURGE
AIR FROM PILOT LINE.
Watch D.C. voltmeter carefully. The reading should
be steady and between 2.0 and 5.0 Volts D.C. If the
reading is too low, slowly turn the needle valve in or out
until satisfactory fl ame signal is obtained (see separate
literature for testing of fl ame safeguard).
Make sure that the combustion air and pilot gas
pressure is suffi cient to provide instant ignition, a stable
fl ame, and fl ame signal. Cycle pilot several times to
insure reliability.
With pilot now adjusted, you can now shut down the
burner by disabling the heat.