Nortec NHPC Humidifier User Manual


 
10-30
Page 76
2008-10-01
coupled circuits can be specified. Coupled circuits will enable the two circuits to be
operated from one controller without compromising the safety features of the
humidifier (order Part No.146-9000).
(3) The humidifier shall be controlled directly using a humidity sensor (transducer)
supplied by others. The sensor will be field wired to the humidifier for a direct
control at the humidifier. The same sensor(s) can be shared in parallel to a Building
Automation System for monitoring purposes. Allows keypad setpoint of rh and
display of actual sensed rh on the NHTC’s graphical display.
(4) Double circuit humidifiers (NHTC 150-200) will require two external sensors by
others to enable each circuit to operate independently of the other. Alternatively,
coupled circuits can be specified. Coupled circuits will enable the two circuits to be
operated from one sensor without compromising the safety features of the NHTC
humidifier (order Part No.146-9000).
(5) All controls are available from the factory as options. If controls were not ordered
with the humidifier, they may be purchased/supplied by others. The following
information is relevant to all controls, factory supplied or otherwise.
(6) A, B and C are to be wired in series (only one path for current) across terminals 1
and 2 on the low voltage control terminal strip, or replaced with a jumper wire for
constant operation.
(a) The Control On/Off Humidistat is wired to make on drop in humidity, break on
rise. Set to desired %rh.
(b) The High Limit On/Off Humidistat is wired to make on drop in humidity, break
on rise. Set to a higher set point (max. 85%rh) as a safety to prevent
saturation.
(c) The Air Proving On/Off Switch is wired to make when sensing air flow, break
when no air flow. As a safety to prevent saturation when no air flow.
(7) The factory offers various versions of A, B and C to suit each application. In
general, A is essential, whereas B and C are highly recommended.
(8) Field wiring from humidistat to humidifier and between devices should be 18 AWG
or heavier.
(9) The low voltage control terminal strip is provided in the electrical compartment. The
internal side is factory wired. The external side is to be field wired, unless the
external controls have been cabinet mounted at the factory.
(10) Each unit is supplied with a wiring diagram adhered to the inside face of the
cabinet door.