AZ Contractor Finds Solution for Wiring Nightmare in the iO Wireless Relay

A recent call of distress about a wiring issue for a rooftop installation of a 2-stage HVAC system was received in our Customer Service department. The contractor was converting an evaporative cooler to a packaged air conditioning unit in Tucson. However, the conversion was going to be a wiring nightmare because of corroded and missing wires. The contractor hadn’t included a total rewire for this project in his original estimate and he was in need of a quick and easy solution.

“That solution,” said our engineer, “is the iO Wireless Relay! And, know you can use as many in one installation as you need!”

The iO Systems Wireless Relay is perfect for situations where you can’t run wire or the existing wire between two devices because they are missing, cut or damaged. With the iO Wireless Relay, two devices can communicate wirelessly–not by Wi-Fi or internet, but by RF satellite technology.

The iO Wireless Relay System consists of 2 units; a Transceiver Module and a Satellite Transceiver Module. The base WRSM transceiver is equipped with 3 digital input channels and 1 relay output channel. The satellite transceiver has 1 digital input and 3 relay output channels. The digital inputs are compatible with most HVAC systems.

The iO-WR communicates on the 915 z frequency band. Each transceiver module uses a redundant transmission protocol for fail-safe protection. If either module does not receive a valid “ON” or “OFF” transmission signal within 60 seconds, the output(s) will be turned off.


  • Power: 24 , 2.8 VAC VA
  • Channels: Base: 3 Send – 1 Receive Satellite: 3 Receive – 1 Send
  • Contact Rating: 1 Amp per channel Frequency: 915 z
  • Operation MH Range: Up to 100 ft.
  • Dimensions: 2-5/8” W x 5-1/8” H x 1-1/8

Installation is Easy

Both the base and satellite transceivers require continuous 24 VAC iO- Base WRBM Transceiver Module

  1. Mount the iO- Base WRBM Transceiver on a non-metalic surface in a location that allows access to the thermostat wiring at the indoor unit. Do not mount inside the unit cabinet or inside any metal enclosure as this will greatly impede transmission distance.
  2. Once the base transceiver is mounted, take the access cover off by removing the two screws. Refer to the iO- wiring diagram. WRBM
  3. Use only 18-gauge solid (not stranded) thermostat wire. When connecting wires to the transceiver terminals, strip approximately 1/4” of insulation and push wire into designated terminal. Do not over-tighten the mounting screws.


The iO- Wireless Relay System has been tested and complies with WR limits for a Class B digital device, pursuant to Part 15 of the Rules of the FCC. These limits are designed to provide reasonable protection against harmful interference in a residential installation.

For more information on iO Wireless Relay, visit or call your Jackson Systems representative at 888-652-9663 to order.

Updated: January 23, 2019 — 6:45 pm

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