(©January, 2008)
Air Technology Systems, Inc.
BNB Ultrasonic Humidifier Installation, Operation & Maintenance Manual
2-4
2.6
Main Power And Control Wiring
For wiring, refer to the electrical drawing supplied with your unit to determine the total number of
interconnecting conductors required for your system and for the proper wire terminations.
For internal wiring of the humidifier, see the “Electrical Circuit Diagrams” on page 7-2.
NOTE
Wiring terminations may become loose during transit of the equipment therefore, verify all wiring terminations
are secure prior to operation.
Verify that the main power supply coincides with the voltage, phase and frequency information specified on the
system nameplate. The nameplate also provides the full load amps (FLA), the current that the unit will draw under
full design load, the minimum circuit ampacity (MCA) for wire sizing, and the maximum fuse size (MFS) for circuit
protection. The power source must be provided with a circuit breaker for safety. Ensure a ground is connected to
the unit. The humidifier is rated to operate with an input of 48VAC/single phase. To maintain warranty coverage,
never allow the humidifier input voltage to exceed 51 volts as damage will occur to the transducers and print
plates.
WARNING
On SATS supplied control boxes, the 48 volt “Hot” wire will not be connected when the unit ships. Depending
on the incoming power supply voltage, the taps on the secondary side of the transformer may be a higher
voltage than labeled. It is important that the taps be checked with a voltmeter to ensure the voltage is within
the proper range. Select the secondary transformer tap that is the closest to 48 volts and connect the “Hot”
wire. Never exceed 51 volts as damage will occur to the transducers and print plates.
CAUTION
It is important to note that if the control transformer is supplied with the equipment by SATS, it is sized and
selected based upon the expected load for the unit. Do not connect any additional loads to the control
transformer. Connecting additional loads to the factory supplied control transformer may result in overloading
of the transformer which will cause the transformer circuit breaker to trip.
2.6.1 Humidistat
The humidistat may be optionally provided by SATS. It should be installed at a well ventilated place where changes
in room humidity can be accurately sensed. If customer provided, the humidistat must be a normally open dry
contact type which closes when the relative humidity drops to a user selected setpoint. Refer to the electrical
drawing for the voltage and current rating requirements for the contact. When one humidistat is used to control
multiple humidifiers, relays should be provided so each humidifier has an independant contact.
