Steam Generating Humidifier - Troubleshooting; Procedures And Terms Used In Diagnosing; Diagnostic Procedures - Troubleshooting; Table 18 Steam Generating Humidifier Troubleshooting Guide - Liebert Himod Operation & Maintenance Manual

7.1

Steam Generating Humidifier - Troubleshooting

PLEASE READ THIS SECTION BEFORE REFERENCING SPECIFIC DIAGNOSTIC MESSAGES.
1. Ensure the installation detail conforms with the recommendations contained in 6.5 - Steam
Generating Humidifier.
2. Understanding the principle of operation is an asset when troubleshooting. A basic description is
provided in 6.5.3 - Start-Up and Operation. For a more detailed understanding, please contact
your Liebert representative.
3. When contacting your local representative or Liebert for troubleshooting assistance, please
ensure the serial number has been obtained for reference purposes.
4. Whenever the troubleshooting steps indicate a problem with the main PCB, first check all
connections at the main control board.
7.1.1

Procedures and Terms Used in Diagnosing

Principle of Operation
The conductivity of the water within the cylinder must be controlled in order for the humidifier to
function properly. The fill and drain rates must be maintained. Filling too quickly can cause over-
amping and automatic shutdown or blown fuses. Filling too slowly can cause insufficient steam out-
put and foaming. Water supply pressure should be between 15 and 150 psig. Draining too slowly can
cause over-concentration and malfunction due to foaming.
7.1.2

Diagnostic Procedures - Troubleshooting

The humidifier controller provides a number of messages to simplify troubleshooting procedures.
Figure 18 presents fault messages displayed by the controller, their meaning and possible corrective
actions. Refer to the following section for detailed information about terms used in the table.
Table 18 Steam generating humidifier troubleshooting guide
Unit Status Lamp
Amber Green
Off Off No power to the board.
Overcurrent. Operating
amperage exceeded
1 flash 130% of rated amps.
Off
sequence Water is drained from
the cylinder (drain
valve on for 10 min.).
No current detection
2 flashes
for 30 minutes with
in Off
continuous call for
sequence
humidity.
4 flashes
End of cylinder life -
in Off
change cylinder.
sequence
Power on. No call for
Off Flashing
humidity.
56 Troubleshooting
Symptom
Check for main power supply fault or blown fuses.
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 transformer circuit.
Check drain valve operation, slow drain time, possible drain restrictions.
Check if fill valve leaks (not holding supply water).
Back pressure may also cause very conductive water conditions.
Was the humidifier short cycling?
Check water level in the cylinder - should be more than 1/4 full. If not
check fill rate, 24 VAC voltage on fill valve terminals (unit must be on with
call for humidity - green light steady on). Verify fresh water supply to the
humidifier. Leaking drain valve can 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)
Check water level in the cylinder, should be about 3/4 full.
Check for foaming if water level lower or cylinder life shorter than
expected.
Change cylinder, clean drain valve.
Ensure on/off control signal received (calling).
Corrective actions