Nortec On Digital Wall & Duct Humidistat - Manual

2556313—E | 3 October 2014 Introduction | 1
On / Off Digital Wall & Duct Humidistat Installation Instructions
This document covers the operation and installation instructions for the following Nortec Duct Humidistat:
Part #:
Description:
2520273* On/Off Digital Duct Humidistat Pkg.
Note: Part #2520273 is comprised of two parts:
2520265
Humidistat w/o sensor
1509857 Duct Sensor
2520273 – On/Off Digital Duct Humidistat Installation
Note: The duct sensor (Part # 2520265) must be wired to the humidistat w/o sensor (Part # 1509857).
Part # 2520265 – Duct Humidistat Package Installation
Location
1. The duct sensor should be installed directly on the duct in an area where the air is well mixed with uniform flow.
2. The supply air sensor should be mounted downstream of the steam distributor at a distance 1.5 times the absorption distance (typically
10-12 feet or 3-3.7m).
3. If a return air humidity sensor is used it should be mounted close to the air inlet but downstream from a return fan if one is present.
Installation
1. Open the housing by removing the 4 screws securing the housing together.
2. Push the probe through the center hole and tighten the 2 mounting screws.
3. Drill a 1/2” (13mm) hole in the duct and insert the probe into the air stream.
4. Secure the sensor to the duct using 2 sheet-metal screws.
5. Connect the signal wires to the sensor terminal strip. Table 1 outlines the terminal layout of the digital humidistat.
6. Connect the plug from the temperature probe to the PCB board into the plug marked ‘PROBE’.
7. Close the cover and secure using the 4 Screws removed in step 1.
Table 1: Humidistat Terminal Layout
Controller w/o Sensor - (Part # 2520265)
Ground 1
24 VAC 2
Digital Out (Common) 3
Digital Out 4
Outdoor Temperature Input 8
Duct Sensor Input 7
Part # 1509857 – Duct Sensor Installation
Location
1. The duct sensor should be installed directly on the duct in an area where the air is well mixed with uniform flow.
2. The supply air sensor should be mounted downstream of the steam distributor at a distance 1.5 times the absorption distance (typically
10-12 ft or 3-3.7 m).
3. If a return air humidity sensor is used it should be mounted close to the air inlet but downstream from a return fan if one is present.
Installation
1. Open the housing by removing the 4 screws securing the housing together.
2. Push the probe through the center hole and tighten the 2 mounting screws.
3. Drill a 1/2” (13mm) hole in the duct and insert the probe into the air stream.
4. Secure the sensor to the duct using 2 sheet-metal screws.
5. Connect the signal wires to the sensor terminal strip. Table 1 outlines the terminal layout of the digital humidistat.
6. Connect the plug from the temperature probe to the PCB board into the plug marked ‘PROBE’.
7. Close the cover and secure using the 4 Screws removed in step 1.
Table 2: Sensor Terminal Connections
Duct Sensor - (Part # 1509857)
24 VAC 1
GND 2
Humidity Output 3