Nortec RH, Installation And Operation Manual, Page: 18 / 60

15 | Installation
External Controls
Control Wiring
Controls are available from Nortec as accessories. If controls were not ordered with humidifier,
they must be purchased or supplied by others. The following information is relevant to all
controls, factory supplied or otherwise. For wiring use minimum 18 AWG and keep as short as
possible.
The RH humidifier can be operated with either On/Off controls only or with On/Off controls and
one modulating input. The modulating input can be from a duct high limit or humidity control
humidistat. See Humidifier Configuration on page 36 to configure the RH for modulation.
Control Location
Figure 15: Control Location
1 Air Proving Switch
•
Locate so that it can sense air flow or lack of it.
2 Duct High Limit – Can be modulating or On/Off humidistat.
•
Locate at least 10 feet from steam distributor or far enough that under normal conditions
steam is fully absorbed.
3 Humidity Control - Can be Modulating or On/Off humidistat
•
Can be located either in return air duct (preferred) or in room being humidified.
•
Avoid placing near discharge diffuser of humidified air.
•
Mount in area representative of room humidity (draft, doorways, sunlight, or overhang such
as a shelf can affect reading).
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.
Caution: Failure to wire the humidifier in accordance with the wiring instructions could
cause permanent damage. Such errors will void the warranty.