Nortec MES2 - Manual (Page 44)

41 | Troubleshooting
General Troubleshooting
The following section provides general guidelines for troubleshooting the MES2 humidifier and
auxiliary components. For detailed troubleshooting information refer to the manuals that were
provided with auxiliary equipment and to Table 7: Troubleshooting MES2 Faults on page 43.
Humidifier
Table 6: General Troubleshooting
Symptom Cause Corrective Action(s)
Nothing happens when On/Off
switch is turned on.
1 Fuse blown 1 Check inline fuse between
On/Off/Drain switch and control
board.
2 Incorrect Voltage 2 Check voltage supplied to
On/Off/Drain switch is 24 VAC.
3 Mains power turned off 3 Turn on mains power.
Humidifier will not humidify or
not reaching RH setpoint
1 Safety loop open. No 24 VAC at
2.
1a Check if there is 24 VAC at point 2 of
Terminal P3 on the control board.
1b Check if air handler is outputting 24
VAC run signal.
1c Check wiring and operation of On/Off
devices connected in series between
output calling for humidity and point 2
of terminal P3.
2 No demand signal (If J10
removed for modulation)
2 Check voltage between P5 and
ground. 25% of full-scale signal must
be present for humidifier to start.
3 Not configured correctly for
On/Off or modulating control
3 Check that J10 on control board is
removed for modulating control and
installed for On/Off control.
4 Capacity has been manually
limited
4 Check Manual Capacity adjustment
potentiometer. Clockwise increases
capacity.
5 Low conductivity water
6 Humidifier undersized
5 Check if yellow LED is on. If operated
on low conductivity water it may take
several hours for the MES2 to reach
full output capacity. This is normal.
During this time the humidifier will not
perform any drains and the
conductivity of the water in the
cylinder will increase.
Humidifier has faulted and
yellow LED is flashing
1 Software has detected an
abnormal condition
1 Refer to Table 7: Troubleshooting
MES2 Faults.