210.100-IOM (JUL 2018)
Page 48
ACUAIR
®
HYGIENIC AIR UNITS
MAINTENANCE
TROUBLESHOOTING
Symptom
Probable causes and Corrections
Motor doesn’t start
Check MOA module to see if in AUTO (green light if on/red light if
fuse is blown)
Check blower door switch
Check smoke/ammonia detectors (if applicable)
Check end switch on OA dampers (if applicable)
Check fuses
Check overloads
Check power to coil on starter
Check power from starter to motor
Motor starts but quits shortly after.
Check fan belts
Check tubes to airflow switch to be clean
Check power through air flow switch
Check rotation of fan
Cooling doesn’t come on
Check MOA module to see if in AUTO (green light if on/red light if
fuse is blown)
Check setpoint for cooling
Check OA lockout setpoint (lockout should be below OA Temp)
Check power to valve
Steam valve doesn’t modulate
Check setpoint for heat
Check OA lockout setpoint (lockout should be above OA Temp)
Check output for steam valve
Direct-fired burner doesn’t light
Check setpoint for heat
Check OA lockout setpoint (lockout should be above OA Temp)
Check MOA module to see if in AUTO ( green light if on/red light if
fuse is blown)
Check burner safety circuit. Eg. High gas pressure switch, Low gas
pressure switch, high temp limit, burner door switch
Check to make sure OUTSIDE air dampers are open and RETURN
dampers are shut
Check burner airflow switch
Check and clean UV scanner
Check and gap pilot assembly (3/16
"
gap)
Check gas supply
Indirect-fired burner doesn’t light
Check setpoint for heat
Check OA lockout setpoint (lockout should be about OA Temp)
Check MOA module to see if in AUTO (green light if on / red light if
fuse is blown)
Check blower on burner
Check lockout alarm on Honeywell control
Check burner airflow switch
Check low fire end switch on burner damper motor
Check spark rod and flame rod
Check pilot assembly
Exhaust fan doesn’t start
Check MOA module to see if in AUTO ( green light if on / red light if
fuse is blown)
Check disconnect switch on fan
Check overload
Check power to and from starter
Check damper end switch ( if applicable )
Summary of Contents for AcuAir
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