Liebert PX018 Installer's/User's Manual page 80

• Reset unit (humidifier): To reset the humidifier, switch the auto On/Off/Drain switch at the
front of the humidifier to the Off position for at least five seconds, then switch it back to the On
position.
• Monitored leg is the primary wire to the cylinder that loops through the current sensing device
of the main PCB. This wire ends at the red cylinder plug at the cylinder.
Table 9.4 Steam-generating Humidifier Status Lamps: Causes and Corrective Actions
Unit Status Lamp
Yellow Green
On On
Off Off
1 flash
Off
sequence
2 flashes
in Off
sequence
4 flashes
in
Off
sequence
Vertiv | Liebert® PDX™ and PCW™ Installer/User Guide |
Symptom
Maximum water level inside cylinder.
No power to the board.
Excess current. Operating amperage
exceeded 130% of rated amps. Water
is drained from the cylinder (drain
valve on for 10 minutes).
No current detection for 30 minutes
with continuous call for humidity.
End of cylinder life - change cylinder.
Corrective Actions
This usually happens on initial start-up after replacing the cylinder (normal).
Water is concentrated with minerals inside the cylinder.
Let unit run; yellow light will disappear when the unit is at full output. This may take a
day or two.
Check for main power supply fault.
Turn power switch to "Drain" position. If drain valve is activated (sound of solenoid),
check connection to the board or board itself.
When no sound is present, check fuse (replace with 3.0 A if needed), transformer
(voltage should be present between fuse holder and ground screw).
Check drain valve operation, drain time, possible drain restrictions.
Check fill valve for leaks (not holding supply water).
Back pressure may also cause very conductive water conditions. Check for short
cycling. Water conductivity too high.
Check water level in the cylinder - should be more than 1/4 full. If not, check fill rate,
24 VAC on fill valve terminals (unit must be on with call for humidity - green light on
steadily). Verify fresh water supply to the humidifier. Leaking drain valve may be at
fault (minerals blocking the plunger).
If cylinder is more than 1/4 full, check primary power, connections to the cylinder,
continuity of wires to cylinder.
Are power wires connected to proper terminals on the cylinder? (Color coding.)
Possibly wrong cylinder type.
Low water conductivity.
Check water level in the cylinder; should be about 3/4 full.
Check for foaming if water level is lower or cylinder life shorter than expected.
Change cylinder, clean drain valve.
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