Nortec Industries GS Series manual Electrical, Primary Wiring, Low Voltage Control Wiring

The vent terminal must be installed in the same atmospheric pressure zone as the combustion air inlet of the humidifier. If this is not possible (as in cases of positive or negative room pressures) the humidifier should be installed with the direct vent option.

ELECTRICAL

PRIMARY WIRING

All work concerning the electrical installation must be performed by qualified personnel.

WARNING: The electrical parts inside the humidifier are very sensitive to electrostatic discharge. Appropriate measures against electrostatic discharge (ESD protection) must be taken when carrying out installation work.

￿The humidifier should only be connected to primary power (mains power) after all installation work has been completed.

￿An external disconnect switch must be installed close to the unit to allow for power interruption during servicing and/or maintenance.

￿Humidifiers require field wiring to primary voltage terminal blocks. Power requirement must be 120V or 208-240 Vac, 15A separately fused circuit, single phase. Use only copper wire with a

minimum 70 ￿C (158 ￿F) temperature rating. Wiring can be fed through a 7/8" hole on the bottom or the top of the control compartment. See Figure #1.

￿When installed, the appliance must be electrically grounded in accordance with local codes or, in the absence of local codes, with the National Electrical Code, ANSI/NFPA 70, and/or the CSA C22.1 Electrical Code, if an external electrical source is utilized.

￿External wiring sizes must be in accordance with NEC and/or CEC and existing local electrical codes and by-laws.

LOW VOLTAGE CONTROL WIRING

All GS models require at least one type of input control signal for unit operation. Refer to the sections below that detail the types of controls that can be used with each model.

Low voltage control terminal strips are provided in the electrical compartment. Internal sides are factory wired. External sides are to be field wired. Refer to the specific control-wiring diagram supplied with each unit.

Field wiring from humidistat to humidifier and between devices should be shielded 18 AWG or heavier and kept as short as possible.

Controls are available from NORTEC as accessories and can be ordered with the humidifier. Controls by others may also be used as long as they meet the criteria noted below. The following is a summary of the common types of controls that may be used with NORTEC Gas Humidifiers.

Wall or Duct Mounted Control On/Off Humidistat: Wired to make on drop in humidity, break on rise to setpoint. Set to desired RH. Can be a make/break set of contacts from a Building Automation System.

Duct Mounted Safety High Limit On/Off Humidistat: Wired to make on drop in humidity, break on rise to safety setpoint. Set to approximately 85% RH as a safety to prevent saturation and wetting in the duct. Highly recommended for ducted applications.

Duct Mounted Safety Air Proving On/Off Switch: Wired to make when sensing air flow, break when no air flow. Used as a safety to prevent saturation when there is no air flow. Highly recommended for ducted applications.

Wall or Duct Mounted Modulating Humidistat: Provides a modulating signal to the unit that represents the output (up to 100%) required from the humidifier. Signal type can be changed in the field via dip switch settings on the logic control board.

All GS models may be configured for either single or dual channel modulation. Control signals can be

0-10 VDC or 0-20 mA (0-5 VDC, 1-5 VDC, 4-20 mA and 2-10 VDC are also available). The unit must be ordered from the factory for the desired signal type and number of channels. When configured for

2-channel modulation the humidifier will generate steam only if both channels indicate a demand. If both channels are demanding steam the humidifier will satisfy the lower demand signal.

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