SMART-Net Relay

The SMART-Net™ Relay is a compact, multichannel line-voltage relay solution that will save you time and money on installation.

Purchase Products

Product features

Compact Design

  • Easily install in small electrical wiring bays within unitary equipment.
  • Installs onto standard electrical box.

Easy Programming with RC-Studio Software

  • Map up to seven input/output objects.
  • Control fan speed using the off/low/medium/high multistate range.
  • Apply pulse-width modulating control using the solid-state relay option and the 0%–100% analog range.

Connection and Addressing

  • Accepts low-voltage 14–26 AWG wires.
  • Four-wire SMART-Net connection.
  • Configure network address using a four-pole DIP switch.
  • Valid addresses are 1–16.

Easy Line-Voltage Wiring

  • Ships with 16-inch 14-AWG color-coded flying leads with prestripped ends.
  • Flying leads exit though a 1/2” NPT threaded conduit hub that offers connection to a junction box.
  • Readily meets electrical code requirements to separate Class 1 and Class 2 voltages.

Optional Fan Speed Control

  • Three dedicated relays for off/low/medium/high speed control.
  • Only one of the three relays may be on at once.
  • Hand/Off/Auto switch protects motor from having two outputs on at once.

Optional Hand/Off/Auto Switches with Status LEDs

  • Three-position slide switches provide Hand/Off/Auto override of each relay.
  • Includes status LED for each relay.
  • Allows you to verify wiring without connecting to software.

Optional Power Supply

  • 24 VDC 10 W supply can be used to power the host controller.
  • Wide input range from 100–277 VAC.
  • Saves space when there is no room for a transformer in a wiring bay.

Optional Inputs

  • Add up to two thermistor or dry-contact inputs.

Optional Relay Outputs

  • Add up to five 5 A 347 VAC line-wire-switched mechanical relays.

Optional Solid-State Relay Output

  • Zero cross switched solid-state relay output.
  • Solid-state relay can be modulating controlled with onboard 0%–100% range for applications like electric reheat.

Optional Conduit Cover

  • Provides Plenum rating to product.
  • Encloses and protects all wires.
  • Accessible top cover for service.

SMART-Net Communication Status LED

  • Indicates SMART-Net connection status and operation.


  • 5 years.
RoHS 3 Certified

Technical specifications

Supply Voltages

  • 5 VDC at 20 mA sourced from controller via SMART‑Net.

Optional Inputs

  • Two thermistor or dry-contact inputs.
  • 12-bit A/D converter.

Wiring Terminals for Low Voltage

  • 14–26 AWG (2.08–0.13 mm2) for SMART‑Net, inputs, and 24 VDC supply.
  • Stranded or solid core.
  • Copper conductors only.

Line-Voltage Wiring

  • 16-inch flying lead 14 AWG (2.08 mm2) stranded core for relays, ground, and power connection.
  • Color-coded wires.

Optional Relay Outputs

  • Range on/off.
  • Zero cross switching.
  • On models with fan speed control (-F models), only two additional latching relays are available.

Relay Load UL/cUL Rating

  • Relay rated for 100,000 cycles.
  • Up to 5 A or 1/2 HP 347 VAC. For models with the -PS option, maximum voltage is reduced to 277 VAC.

Fan Speed Control (-F Models)

  • Provides three-relay, three-speed fan control.
  • Connects to line-voltage-switched fan speed.
  • On -F models, mechanical relays 1–3 are interlocked.

Solid-State Relay Output (-SSR Option)

  • 0%–100% range.
  • Duty cycle period is 4 seconds with 0%–100% duty.
  • 15 A, 347 VAC.
  • Solid-state relay output is typically in place of the fifth mechanical relay; models with the -SSR option have a maximum of four additional relays.

Conduit Cover (-CC Models)

  • 50 mm conduit cover for low-voltage wires.
  • 1/2" NPT knockout.

Hand/Off/Auto Switches (-H Option)

  • Up to five SP3T slide switches to manually set outputs to Hand, Off, or Auto.
  • Green status LED.
  • Software feedback to show the current switch position.

Power Supply (-PS Option)

  • 24 VDC 10 W line-powered power supply to provide controller power.
  • Powers host controller only.
  • Powered from input 100–277 VAC, 50/60 Hz, 250 mA. Connected by black and white 14 AWG flying leads.

Enclosure and Mechanical

  • Robust extruded aluminum.
  • 1/2” NPT with threaded lock nut to connect to junction box.


  • 12.42 cm L x 12 cm W x 6.4 cm H
    (4 7/8" L x 4 11/16" W x 2 1/2" H).

Mounting Hardware

  • Supplied with two 1/2" sheet metal screws.
  • Two additional 1/2" screws supplied with optional conduit cover.


  • 0.493 kg (1.09 lb).

Ambient Limits

  • Operating: 0°C to 50°C (32°F to 122°F).
  • Shipping: –25°C to 60°C (–13°F to 140°F).
  • Humidity: 10%–90% RH noncondensing.


  • CE.
  • EN 60730-1.
  • UL 60730-1 Listed.
  • WEEE.


Line voltage control

Expansion Modules

SMART-Net™  Expansion Board
For SMART-Net™ devices that use terminal-block connections instead of modular RJ11 connections, the SMART‑Net Expansion Board maximizes both the number of SMART‑Sensor devices you can use and the combined SMART‑Net cable length you can connect to a host controller. Powered externally or by the host controller with 24 VAC or VDC, the SMART‑Net Expansion Board supplies power for up to 16 SMART‑Sensor devices and does not repeat the SMART‑Sensor signal, simplifying field wiring and providing a high degree of flexibility.