Emerson PFH020A-L, User Manual

Page: 72 / 117

Troubleshooting
65 Liebert
®
Mini-Mate2
™
Humidifier does
not operate
DIP switch not set to enable
humidifier option
See DIP switch settings Table 20 .
“HUMIDIFY” not displayed at
control panel
Increase humidity control setpoint and sensitivity to require
humidification.
Defective board
Check voltage at P3-1 and P1-9 on interface board for 24 VAC ±
2 VAC. If no voltage, check wiring and/or replace board. Check
wiring from control panel to board.
Failed humidity sensor
Humidity display will indicate dashes. Check wiring from
temperature/ humidity board to the control board and from the
wall box to the control board. Replace wall box or
temperature/humidity circuit board (if remote).
No water flow
Make sure switch is in Run position. Check humidifier water
supply (including filter screen) and check nylon overflow line if
canister is full.
Canister fill rate is not keeping
up with the steam output
Check fill valve screen opening and capillary tube for
obstructions. Check water supply pressure (minimum 10 psig
[69kPa]).
Fan will not operate
at low speed when
selected from control
panel.
Open wiring or failed board
Verify “LOW FAN” is displayed at the control panel. Check for 24
VAC ± 2 VAC at terminals P3-4 and P1-9. If no voltage, check
wiring and/or replace interface board. Check fan relays.
Fan will not operate
at low speed during
dehumidification
Temperature requirement is too
high.
Verify with display. Cooling requirement overrides
dehumidification.
Cooling cycle too
short
Sensor response delay too short
Increase sensor response delay. See 6.1.9 - Calibrate
Sensors .
Condensate pump
does not operate
Open or short circuit in wiring Find open or short circuit and repair power to pump.
Continuous Cooling Failed temperature sensor
Temperature display will indicate dashes. Check wiring from
temperature/humidity board (remote sensors) to the control
board or from control board to wall box. Replace
temperature/humidity circuit board (remote sensors) or wall box.
Continuous Cooling
Dehumidification
Humidification
Shorted wiring or failed control
board
Check wiring and/or replace control board.
Table 26 Troubleshooting (continued)
Symptom Possible Causes Check or Remedy