Liebert 8 Tons, 50 & 60Hz Replacing the Humidifier Canister, 6.2.7Circuit Board Adjustments

Models: 50 & 60Hz 8 Tons

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Replacing the Humidifier Canister

System Operation, Testing, and Maintenance

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.

6.2.7Circuit 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

SW2

SW3

SW4

Amps

 

 

 

 

 

 

208

On

On

On

Off

8.9

 

 

 

 

 

 

240

Off

On

On

Off

8.5

 

 

 

 

 

 

380/415

Off

Off

Off

Off

5.2

 

 

 

 

 

 

460

On

On

On

Off

4.5

 

 

 

 

 

 

575

On

On

Off

Off

3.4

 

 

 

 

 

 

56

Page 64
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Liebert 8 Tons, 50 & 60Hz user manual Replacing the Humidifier Canister, 6.2.7Circuit Board Adjustments