Armstrong EHF-3 - Humidistat Troubleshooting

Installation and Maintenance
EHU-600 Series Humidifiers
31
Humidistat
Troubleshooting
If the Armstrong Humidistat is mis-wired Table 31-1 shows the unit
response. * indicates wrong wire connected. W, G, and B stand for
white, green, and black, the wire colors on the humidistat. See Section
7 for more information on control humidistat wiring.
Table 31-1
Terminal
Demand Meter Functional Response
22 6 7
Responds to stat normally, Correct wiring. Unit fills
W G B 0% with jumper disconnected. and drains normally.
100% with sensor out.
B* G W*
5 demand lights flicker with Contactor cycles or
B* W* G*
or without sensor or pigtail chatters. Unit fills continuously.
G* B* W*
5 demand lights flicker with Contactor chatters
or without sensor or pigtail. Unit will not fill.
G* W* B*
1 or no demand light(s) flicker Tank off. Contactor will
WB*G*
with or without sensor or pigtail. not energize. Unit will not fill.
Table 31-2 shows the units response if jumper BJ2 is in the wrong
position and the Armstrong humidistat is wired correctly. See Section 7
for more information on jumper locations and selections.
Table 31-2
Jumper
BJ2 Pin No. Labeled Functional Response
4 1.9-3.9 Correct Pin No. Unit
responds normally.
3 2-10V/4-2MA 0% demand. Unit will
not fill. Tank off.
2 0-135 On/Off Unit responds normally
but over wider %RH range.