210.100-IOM (JUL 2021)
Page 40
AcuAir Hygienic Air Units
Operation
Employ refrigerant sensing devices in the hygienic air sys-
tem. Select and locate these sensors based on the refrig-
erant within the system. When the refrigerant is ammonia,
the sensors work well when placed inside the AcuAir
®
unit
immediately downstream of the cooling coil.
Examine your environment. If structure, equipment, or
other elements of your facility show rust or corrosive
effects, the evaporator coils are not likely to be impervi-
ous to the same effects of the environment. Consider this
when formulating your maintenance program.
Gas heat start-up
1. Close the manual gas shutoff valve external to the
burner.
2. Turn off the electrical power to the furnace.
3. Set the temperature to the lowest possible setting.
4. Set the burner controls to the
OFF
position.
5.
Wait five minutes to clear out any gas. Then smell for
gas, including near the floor.
6. Set the burner controls to the
ON
position.
7. Close the door on the front of the gas manifold.
8. Open the manual gas valve external to the furnace.
9. Turn on the electrical power supply to the furnace.
10. Set the controls to the appropriate temperature.
NOTICE
This heater is equipped with an ignition device that
automatically lights the burner. Do not try to light
the burner by hand.
NOTICE
There is an approximate 30 s delay between controls
energizing and burner firing.
Figure 47: AcuAir direct fired gas burner
Gas heat shutdown
1. Set the controls to lowest setting.
2. Turn off the electrical power supply to the furnace.
3. Set the burner controls to the
OFF
position.
4. Close the manual gas shutoff valve external to the
furnace.
Figure 48: AcuAir gas burner wrapper
24 hr run-in
After 24 hr of operation under load, perform the following
services:
1. Examine the unit for any unusual noise or vibration.
2. Readjust fan belt tension if required.
Start-up after prolonged shutdown
It is imperative that maintenance personnel conduct a
thorough start-up before running the unit after a pro-
longed shutdown.
At minimum, the following checks must be preformed:
1. Clean any debris from guards, fans, eliminators, heat
transfer coils, and filters.
2. Turn the fan(s) by hand to ensure rotation without
obstruction.
3. Verify and, if necessary, adjust the fan belt tension.
See
Inspecting V-belts and sheaves
and
4. Before start-up, lubricate the fan shaft and motor
bearings. The ball bearings are factory lubricated, but
must be relubricated if the unit has been sitting on site
for more than a year before start-up.
5. Check the locking collar on each fan shaft bearing and
tighten if necessary.
6. Verify the voltage and current of all three legs of the
fan motors. Ensure the current does not exceed the rat-
ed service factor. After prolonged shutdowns, check the
motor insulation with a Megger Tester before restarting
the motors.
7. Start the fan or fans and verify correct rotation as indi-
cated by sticker on unit.
