Emerson Liebert CRV, User Manual

Page: 189 / 192

Humidifier—600mm (24") Units Only
179 Liebert
®
CRV
™
A.1.6 Humidifier Troubleshooting
Terms Used
• FLA (Full Load Amps) are amps listed on the humidifier specification label.
• Short cycling occurs when the humidifier’s “On time” is less than 10 minutes upon a call for
humidity. To correct short cycling, all humidifiers have a capacity adjustment that allows the
output of the humidifier to be reduced to as low as 20% of rated output, thus extending the “on
time” required to maintain output.
• Foaming can occur when the impurities already in water reach an excess concentration as a
result of boiling away water and continued boiling agitates the contained water. The humidifier
electronics are designed to prevent foaming, although in extreme cases water will foam with little
concentration, making it necessary to increase the drain time of the water contained in the
cylinder. Foaming is normally caused by short cycling, a restricted drain or back pressure. The
foam generated in these instances is conductive and may lead to false full-cylinder indication if
the level of the foam approaches the top of the cylinder.
• Back pressure is the restriction of steam flow caused by long steam runs, improperly sloped
steam lines, elbows changing the direction of steam flow from horizontal to vertical without a
drain leg, any plumbing detail allowing the accumulation of condensate, undersized steam line,
improper steam distributor, downward air flow onto the distributor causing excess static pressure
at the steam outlets, or high static pressure ducts (not probable). To overcome excess static
pressure in the duct, use a fill cup extension kit. In downflow applications, a downflow distributor
should be used, but in some cases the fill cup extension will also be required.
• 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 42 Humidifier troubleshooting
Unit Status Lamp
Symptom Corrective Actions Yellow Green
On On
Maximum water level
inside cylinder.
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.
Off Off No power to the board.
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).
1 flash
sequence
Off
Excess current. Operating
amperage exceeded
130% of rated amps.
Water is drained from the
cylinder (drain valve on for
10 minutes).
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. Was the humidifier
short cycling? Check for short cycling. Water conductivity too high.
2 flashes in
sequence
Off
No current detection for 30
minutes with continuous
call for humidity.
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 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.
4 flashes in
sequence
Off
End of cylinder life -
change cylinder.
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.