1BHF t %3*45&&. 7BQPSMPHJD *OTUBMMBUJPO BOE 0QFSBUJPO .BOVBM
Operation
Tr o u b l e s h o o t i n g g u i d e
Table 76-1:
Troubleshooting guide (continued)
Tr
ansmit
te
r or
humidistat
issues
Issue
Possible causes
Actions
Alarm:
RH signal out of range
When transmitter or humidistat alarms appear,
possible causes are:
t 0QFOTIPSUFEPSJODPSSFDUXJSJOH
t *ODPSSFDUTJHOBM
t (SPVOEMPPQ
t 4JHOBMFYDFFETSBOHFMJNJUT$PSSFDUJOQVU
signals are: 4-20 mA, or 0-10 VDC
t $IFDLWPMUBHFTBUCPBSEUFSNJOBMT
At terminal P11
-- RH signal: 2-10 VDC.
-- Dew point signal: 2-10 VDC.
-- Demand signal: 0-10 VDC.
At terminal P13
-- Duct high limit signal: 0-24 VDC, 2-10 VDC.
At terminal P14
-- Auxiliary temp sensor or temperature
compensation sensor: 2-10 VDC.
t $IFDLPVUQVUPOUSBOTNJUUFS
-- If there is no output, replace transmitter.
-- Verify output is 4-20 mA.
-- Calibrate transmitter or humidistat
if necessary.
t *TPMBUJPODPOUSPMCPBSECZPUIFSTNBZOPUCFDPNQBUJCMF$POTVMU
DRI-STEEM.
Alarm:
Dew point signal out of range
Alarm:
Demand signal out of range
Alarm:
Duct RH signal out of range
Alarm:
Aux temp sens out of range
Alarm:
No SDU airflow
t 4%6CMPXFSPSBJSGMPXQSPWJOHTXJUDIJT
incorrectly wired
t $IFDL4%6GPSQSPQFSXJSJOH
t 4%6CMPXFSDPWFSJTPGG
t *OTUBMMDPWFS
t 4%6CMPXFSNPUPSJTJOPQFSBCMF 4%6GBOEPFT
not start)
t 3FQMBDF4%6CMPXFS
t#SFBLFSUSJQQFE
t3FTFUCSFBLFS
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