Operating instructions

67
Operation
Operation:
Troubleshooting guide
Troubleshooting guide.
Problem
number
Problem Possible cause Action
32 Humidity below
desired level
 Unit operating but
fails to meet required
humidity output
 No call for humidity
from humidistat or
from control and high
limit humidity
transmitters
 Excessive outside air
volume
 Unit undersized; replace with a larger
unit or add additional humidifier.
 Skimmer rate is too high.
 If drain valve will not close fully,
determine the cause and clean, repair
or replace as needed.
 If drain pipe water seal is allowing
steam to go down the drain, repair as
needed.
 If there is an improper water seal
height, increase to recommended
height. (See humidifier tank manual.)
 If there is excessive internal steam
pressure, determine the cause of the
high pressure (e.g., high duct static
pressure, undersized orifices in
dispersion tubes, water, or crushed
vapor hose) and repair as required.
 Replace leaking gasket or vapor hose.
 Recalibrate if controls are out of
calibration.
 If fill valve is stuck open, repair or
replace.
 If zone valve will not open, repair or
replace.
 Low or no signal strength from
humidistat. Check for proper wiring.
 Check humidity transmitters (4-20 mA
output).
 Adjust set point if VAPOR-LOGIC
®
3
set point is too low.
 Verify proper operation of fans,
dampers, VAV systems, etc.
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