System Protect and Dropped Connections using ADC-T3000 Thermostat

The ADC-T3000 Thermostat requires a minimum of 24VAC in order to operate properly. Thermostat outputs are limited to a maximum of 1 Amp each. During heat or cool operation, transformer voltage can drop below 24VAC causing the ADC-T3000 to lose communications and/or enter “protect” mode for extended periods preventing proper heat or cool operation. Some residential and commercial systems also draw more than 1 Amp when heat or cool is called for. This can also trigger the thermostats “protect” mode for extended periods preventing proper heat or cool operation. recommends the use of “isolation relays” to eliminate these issues and ensure reliable operation. The relays recommended by ADC require one relay per channel meaning that most systems will require 3 to 6 relays in total. They require specials tools and connectors to install and take up significant space. ADC does not provide support for how to wire these relays to your thermostat and/or HVAC system.

The ISO series of HVAC Isolation relays are designed specifically for this application. 6 relays are built-in supporting most residential and commercial systems in a single device. Easy to use screw terminals require no special tools or connectors, and the entire device will conveniently fit into a single or dual gang electrical box. The ISO6 product is clearly labeled with wire labels matching those on your thermostat and HVAC system making installation and wiring a simple task.