Nortec NH Series - Manual (Page 65)

10-40
Page 58
2008-08-28
Table 2. Ensuring A Demand Signal
2. TROUBLESHOOTING DISTRIBUTORS
CAUTION
KEEP IN MIND WHEN TROUBLESHOOTING DISTRIBUTORS THAT
THEY ARE BEING USED WITH STEAM AND THEREFORE, ARE AND
CAN REMAIN VERY HOT DURING THE TROUBLESHOOTING
PROCESS.
A. TROUBLESHOOTING ATMOSPHERIC DISTRIBUTORS
(1) If the distributor is spitting out water, ensure that the distributor is installed level and
check the condensate return for proper slope, check head above the trap, and check
the trap that it is clear of obstructions.
(2) If the distributor is condensing inside the duct, make sure the installation clearances
are as indicated in Chapter 10-10 Installation, and make sure that the design conditions
have not changed. If over humidification of the duct results, check controls and safeties
(ensure safeties are properly installed and functioning).
3. SAM-e TROUBLESHOOTING
A. PROCEDURE
(1) If the SAM-e is spitting out water, ensure that the distributor is installed per instructions
in Chapter 10-10 Installation and check the condensate return for proper slope and trap
and that it is clear of obstructions. The condensate return must be the lowest point of
the SAM-e header.
Check Why and How
Safety Loop (terminal 1
and 2) is closed The safety loop is checked to ensure that it is safe to operate. Checking to see 24 VAC from
terminal 1 to ground, and terminal 2 to ground should indicate whether is closed.
If found to be open, isolate which component in the safety loop is open to solve the issue. If
suspect, confirm that it is connected and operating properly.
Channel 1 has a signal. Whether for on/off or modulating, a voltage potential signal must be present between
terminal 3 and 4 for the humidifier temperature.
If on/off there should be 5 VDC.
If VDC modulating, at least 25% of total possible signal must be present.
If mA controlled, at least 25% of total possible signal must be present.
If Transducer signals, the unit setpoint must be higher then the sensed room RH signal.
Channel 2 has a signal Only applicable if configured to accept dual channel input.
If VDC modulating, at least 25% of total possible signal must be present.
If mA controlled, at least 25% of total possible signal must be present.
If Transducer signals, the high limit setpoint must be higher than the sensed RH signal.