Control Wiring; Control Location - Nortec NHTC Installation And Operation Manual

External Controls

Control Wiring

Controls are available from NORTEC as accessories. If controls were not ordered with humidifier
they must be supplied by others. The following information is relevant to all controls, factory
supplied or otherwise. For wiring use minimum of 18 AWG and keep as short as possible.
The NHTC humidifier can be operated with two modulating inputs. The NHPC has one
modulating input which can be used for a duct high limit or humidity control. Both the NHTC
and NHPC can be operated as On/Off. See Control Setting on page 52 for configuration.
Caution: Failure to wire the humidifier in accordance with the wiring instructions could
cause permanent damage. Such errors will void the warranty.

Control Location

1
Air Proving
Switch
1 Air Proving Switch
 Locate so that it can sense air flow or lack of it.
2 Duct High Limit
 NHTC can be modulating, On/Off, or a humidity sensor. NHPC can be modulating or On/Off.
 Locate at least 10 feet from steam distributor or far enough that under normal conditions
steam is fully absorbed.
3 Humidity Control
 NHTC can be Modulating, On/Off, or a Humidity Sensor. NHPC can be modulating or On/Off.
 Can be located either in return air duct (preferred) or in room being humidified.
 Mount in area representative of room humidity (draft, doorways, sunlight, or overhang such
as a shelf can affect reading). Avoid placing near discharge diffuser of humidified air.
Note: Regardless of selecting on/off or modulating control method, NORTEC humidifiers
must have a closed circuit across its on/off security loop control terminal to operate.
NORTEC highly recommends the use of a high limit humidistat and an air proving switch
in series for this function.
10 ft min
2
Duct High
Limit
Figure 17: Control Location
3
Humidity
Control
(Return Air
Duct or
in Room)
Installation | 20