56
No control voltage
present
Heater fuses open
Transformer secondary
circuit breaker tripped
Field wiring not
installed
Field-supplied remote
fault indicator lamp is
burned out.
Remote fault
VAPOR-LOGIC
3
relay
is not switching.
No power, or incorrect
voltage to VAPOR-
LOGIC
3
board
Modular
communication cable
is disconnected.
Open, shorted, or
incorrect wiring of
transmitter or humidistat
Signal by others.
Incorrect, out of range
or miswired.
Gound loop
Control signal by
others has exceeded
the range limits.
Correct control signal
to 4-20 mA, 0-135
Ohms, or 0-15 VDC.
Operation
Operation:
Troubleshooting guide
Troubleshooting guide.
1
2
3
4
Green power indicator
light is off.
No remote fault
indication
No readable
information on
keypad/display
Humidity transmitter
fault
Check for proper supply voltage.
Check heater fuses for voltage present
at transformer.
Check for wiring shorts; reset breaker.
Provide field wiring to a remote fault
indicator from VAPOR-LOGIC
®
3
terminal block J22.
Check if lamp by others is burned out;
replace if needed.
Check relay continuity (VAPOR-
LOGIC
3
terminal J22) for contact
closure.
Check main power supply.
Connect modular cable.
Check D.C. supply voltage terminals:
21+, 23-(21 VDC)
If there is no output, 4-20 mA, replace
transmitter. Transmitter by others is not
compatible. Consult DRI-STEEM.
Isolation board by others.
Recalibrate if there is a calibration
error: Normal Range 4-20 mA = 0-
100% RH 12 mA = 50% RH.
Measure for normal 1-5 VDC range on
Control RH transmitter or 4-20 mA by
others: 22 +, 23-.
Problem
number
Problem
Possible cause
Action
More on next page ...
VL3-IOM-0301-METRIC.pdf 60
11/19/2009 9:22:39 AM
Summary of Contents for Vapor-logic3
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