Circuit Board Adjustments; Table 17 Humidifier Control Board Dip Switch Settings - Liebert 8 Tons User Manual

Replacing the Humidifier Canister
The proper procedure to replace the humidifier canister is:
1. Turn off the humidifier by lowering the humidity setpoint below the ambient humidity level.
Record the original setpoint.
2. Turn unit off at wallbox.
3. Place the RUN/DRAIN switch in the DRAIN position to drain the water from the canister.
4. Return the RUN/DRAIN switch to the RUN position after the canister has drained.
5. Turn OFF the power at the main unit.
6. Remove the cover from the humidifier cabinet.
7. Locate the power wires to the steam canister. They are connected to the canister with 1/4" quick
connects. Make note of the wiring configuration before removing any wires. Refer to schematic on
unit. Slide the rubber boot back to expose the connections. Remove the three (3) power wires and
the canister full wire. Do not loosen the screws that secure the electrodes.
WARNING
!
Canister and steam hose may be hot! Allow time for the humidifier to cool before replacing
parts.
8. Loosen the steam outlet hose clamps and slide the steam hose away from the canister fitting.
9. Remove the canister.
10. Reverse Previous steps to re-assemble humidifier, paying special attention to the following:
WARNING
!
Hazardous voltage! use extreme caution. Circuit board adjustment should be performed by
qualified personnel only.
Power should be disconnected prior to the procedure.
6.2.7

Circuit Board Adjustments

The humidifier control board governs humidifier operation. There are three potentiometers mounted
on the board and can be used to adjust for extreme water conductivity conditions.
POT2 controls the amperage at which the drain will energize and is clearly marked in percentages.
This adjustment is factory set at 85%, which indicates that the unit will drain when the amperage
falls off to 85% of the capacity setpoint. Raising the value increases the frequency of drain cycles.
Lowering the value decreases the frequency of drain cycles.
The frequency should be increased for highly conductive water and decreased for less conductive
water. If adjustment is necessary, and a change of three to four percent in either direction does not
permit normal operation of the unit, consult your Liebert supplier.
The POT1 controls the duration of the drain cycle. This adjustment is factory set at 60 seconds
(1 VDC) and should not be readjusted without consulting your Liebert supplier.
The DIP switch settings are used to set the capacity of the humidifier. If the humidifier is replaced in
the field the DIP switches should be set to the required settings described below.
Table 17 Humidifier control board DIP switch settings
Voltage SW1
208 On
240 Off
380/415 Off
460 On
575 On
SW2 SW3 SW4
On On Off
On On Off
Off Off Off
On On Off
On Off Off
System Operation, Testing, and Maintenance
Amps
8.9
8.5
5.2
4.5
3.4
56