Nortec NHPC, NHTC manual 10-30, Page 76

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.

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