Reznor ADFH Unit Installation Manual - Manual (Page 22)

Form I-ADF, Page 22
Optional
Door Switch
Optional
Firestat
Control used for
Outside Air Cutoff and
Discharge Low
Temperature Limit
(Freezestat)
9.0 Commissioning
and Startup
9.1 Checks Before Startup
 1. Check to be sure that all field-installed accessories are installed. If equipped with
an optional dirty filter switch, check that the sensor tubing shipped in the unit is
extended through the filter rack and attached correctly.
 2. Check all field-installed wiring.
 3. Check all ductwork for obstructions; open all diffusers.
 4. Turn the remote three-position switch or optional summer/off/winter remote
console switch to OFF position. To prevent someone from turning the system on,
tape the switch leaving a note that it should be left in the OFF position.
5. Check Disconnect Switch --

Turn disconnect switch OFF.
perature of the incoming outside air. The outside air cutoff (high ambient control) is
factory set at 60°F (adjustable 25-250°F). The burner reacts differently depending on
the entering air temperature and the setting on this control. The burner --
• may not ignite (pilot valve will not open);
If the actual temperature of the outside air is above the setpoint on the outside air
control, the burner will not ignite.
• may modulate to satisfy discharge setting;
• may shutdown; or
Burner shutdown or modulating operation will depend on the temperature rise
between the outside air and the discharge air setting.
• may remain on continuous low fire.
If the outside air control is set too high, the burner will continuously burn on low fire
as long as the control switch is set to "winter".
When the outside air control is set properly for the climate, the system blower will con-
tinue to provide the required makeup air (ventilation) at the ambient outdoor tempera-
ture (burner not operating) even when the control switch is set to "winter".
If at startup, it is determined that the outside air cutoff control is not set properly,
change the setting on the control (located in the main electrical compartment) and test
for proper operation.
Discharge Temperature Low Limit (Option BE2)
If the system has an optional low limit switch for discharge temperature (freezestat), the
control is in the blower section electrical box. The sensing bulb must be field-mounted
in the blower discharge duct connector. Uncoil the control and extend the bulb to the
blower discharge, being careful to not interfere with any mechanical parts. Use the bulb
holder provided and mount the sensor according to the manufacturer's instructions.
Door Switch (Option BX1)
If the system is to be used as an overhead door heater, an optional door switch (Option
BX1) must be installed. The function of the switch is to energize and interlock the sys-
tem when an outside overhead door reaches approximately 80% of full open travel.
The switch will de-energize the system when the overhead door closes approximately
20%. Follow the installation instructions in the door switch option package and the wir-
ing diagram.
Firestat (Option BD5)
If the system has an optional firestat, the control is shipped separately for field installa-
tion. Mount it on the discharge ductwork so that the sensor extends into the duct. This
control requires manual reset so should be installed in an accessible location.
Follow the manufacturer's instructions and the wiring diagram to mount the firestat and
connect the wires in the blower section electrical box. The firestat is a manually reset
control; check reset when starting the unit.
Optional Field-Provided Computer Control (with Option AG37 only)
If the system includes Gas Control Option AG37, the gas valve and burner modulation
are controlled by a field-supplied 0-10VDC or 4-20 milliamp computer signal.
Follow the signal conditioner manufacturer's instructions included with the system for
connecting to the field-provided control.
8.0 Controls
(cont'd)