Dry-contact functionality

The 20A relay is configured with 2 blue wires connected to an isolate relay output that can be used to interface with a dry-contact closure. The term "Dry-contact" means that the relay contacts are fully isolated and are not connected to an internal voltage source - the 2 blue wires are connected to each other (low resistance) when the relay is ON and the 2 blue wires are disconnected (high resistance) when the relay is OFF. Because they are "dry-contacts", this relay can be used to interface with a secondary signal or system of the same or different voltage and either AC or DC powered. The 20A controller still requires a connection to an operating supply voltage of 100-277VAC (white and black wires) while the relay contact (blue wires) can be connected to a different signal or circuit, as needed.


This flexibility allows the controller to be used in many applications, including:

  • Line voltage switching - To use the controller for switching a load that will connect to the same line voltage circuit that powers the device, connect one Blue wire (input - either blue wire works) to the Black wire and to the incoming Line voltage. The second blue wire will be the switched voltage output to power the load. Link to a switch or sensor for ON/OFF control.
  • HVAC interlock - The 20A controller is powered from 100-277VAC and the dry contact interrupts power to the thermostat. Link to one or more magnet contact sensors to disable HVAC when outside windows or door are left open.
  • Momentary pulse closure - Use for motor control, motor starter and other applications - 20A controller is powered by 100-277VAC and the dry contact is configured in momentary mode so that the contact is closed while the switch is held and releases when the switch releases. Configuration options: 
    • Field or factory activate DC mode for use with DC signals (AC mode is the default)
    • Factory only - activate Minimum ON timer to stretch the pulse so it is on for a minimum time anytime the switch is pressed
    • Factory only - Other factory configured timers available for specific applications: Auto-OFF, Auto-On, Minimum On, Maximum On, On Delay, Minimum Off, Maximum Off, Off Delay.

Operating Modes

DC Mode

By default the controller supports AC modes and if used with DC loads, the output will latch ON and only turn OFF when power is removed from the dry contact input. To use with DC loads, either request that it be pre-configured at the factory or field activate DC mode using commissioning software or the following pushbutton sequence:

DC Mode activation with push button sequence: (for E9X-RUV-4IBTP)

  1. Power the device
  2. Hold down the menu button for at least 15 seconds. After the LED blinks amber 3 times, release. The advanced menu is now active. If the relay is clicking on and off, the button was not held long enough. Power cycle or wait 30 seconds for clicking to stop and try again.
  3. Press and release the Select button 5 times. The LED should be blinking a 6 amber blink pattern
  4. Press and release the Menu button, it should now be blinking a single green blink pattern.
  5. Press and release the Select button 5 times, it should now be blinking a 6 green blink pattern
  6. Press and release the Menu button. it should now be blinking a red pattern. If the LED is showing a 1 red blink pattern, press and release the select button 1 time. LED should now be showing a 2 red blink pattern. 2 blinks = DC load, 1 blink = AC load (default)
  7. Press and release the Menu button. The LED should show solid green for a few seconds then start its blink pattern again.
  8. Wait one minute for the device to exit the advanced menu