MANUAL CAPACITY ADJUSTMENT
The NHB humidifier is rated in lbs/hr of steam output capacity. Set to 100%, it will operate at full output until the humidistat has sensed that the humidity has reached setpoint. Then it will stop the humidifier by breaking control circuit
If the humidifier is oversized, the humidistat will be quickly satisfied and stop the humidifier. As humidity level drops the humidistat calls again. It is quickly satisfied and stops again. The resultant
A manual capacity adjustment potentiometer
(“pot”) is provided on the NHB main pc board for that purpose. It is marked “Sx%” and is adjustable from 20 to 100% of rating.
The NHP humidifier, utilizing modulation control, does not have the same problems of oversizing. It reacts to the modulation signal and varies its capacity automatically. However, if you wish to turn down the capacity, the NHP has the same manual capacity adjustment potentiometer (“pot”) that the NHB has.
OTHER POTENTIOMETERS
Do not adjust any other potentiometers (“pots”) on the pc board(s). They are
DETECTING WATER SUPPLY DEFICIENCY
Knowing how long it normally takes to fill each size steam cylinder, each humidifier’s pc board is factory configured to an acceptable maximum filling time (using jumpers). If it is filling too slowly, when the time expires the electronics stops the humidifier. To indicate this, the green light goes out and the yellow light goes on.
REMOTE INDICATION
Every NHB/NHP comes factory wired to provide 24 VAC (100 mA max.) at
DOUBLE UNIT OPERATION
Turn both switches on. If there is a demand for humidity, the green status lamp will indicate that the circuit is operating.
On the NHP, the optional output indication meter will steadily increase until the meter reads maximum output. Maximum output depends on the manual capacity setting of the unit and/or the continuous control demand.
The NHB/NHP has built in diagnostic capabilities and will shutdown for the following reasons:
-No current (similar to NHMC Error Message 5).
-Excess current (similar to NHMC Error Message 1).
-Change cylinder/end of life (similar to NHMC Error Message). NHB will shutdown on this fault.
In all cases, when an error is detected, there will be 24 VAC potential (100 mA max.) available at terminals 20 and 61 of the internal external white terminal strip.
BLOWER PACK OPERATION
Blower packs are equipped with a control thermostat mounted on the steam distributor. As soon as humidifier generates steam, the contact is closed and the fan is started. When steam is no longer being generated, the fan cuts out with a delay.
If blower packs get overheated (malfunction of the air circulation), the manual reset safety thermostat interrupts the steam generation. To reset, switch off the humidifier and wait until the steam distributor cools down. Then remove
Units are equipped with speed select switch. The switch is located on the
To avoid condensation on the cabinet parts, run blower pack on high speed when humidifier delivers 75 lbs/hr or 100 lbs/hr of steam.
MAINTENANCE
WARNING! The plumbing and electrical compartments contain high voltage components and wiring. The access door(s) is equipped with a lock. Access should be limited to authorized personnel only.
WHEN TO REPLACE THE STEAM
CYLINDER
The steam cylinder is disposable and must be replaced at end of cylinder life. Cylinder life is
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