October 3, 2005

Utility Load Control - Combination Products, Same Facilities

The majority of the Electro forced air and disconnect products have provisions for "tying together" more than one heating product controlled by a single utility receiver. Typically this feature can provide an installation cost saving and simplify the installation.

We notice often the installer is not aware of these Electro features and winds up adding extra relays, extra load control receivers, etc. to the project.

In general this function appears on forced air control boards with three tabs marked - COM, EL, SB or three pigtailed wires as yellow/grn, blue/yel, orange/blk. In both cases this represents a form C isolated relay contact where the COM or yellow/grn is the relay "swinger", EL or blue/yel is closed during electric mode, SB or orange/green is closed during standby or interrupt.

Below is the list of specific products which have this feature and the drawing showing this set of relay contacts.

  • Electro-Mate, DFC type, EM-LV or EM-LD Series
    • DFC information sheet ED105
  • HeatChoice plenum heater
    • Installation Manual EI203, page 11
  • WarmFlo I/F, WF-EZ3
    • Drawing HH316, use COM and EL
  • WarmFlo I/F, WF-EM3 or WF-LGR4
    • Requires extra relay, EE-5053, Drawing HH339
  • Dual Energy Furnace
    • Drawing DH101, use COM and EL
  • Peak Interrupter, PI-***A Series
    • All installation drawings, upper right detail bubble
  • Peak Interrupter, PI-***K Series
    • Add relay EE-5053
  • Main Lug Disconnect, SI-*** Series
    • ED106
  • Main Lug Meter Socket Disconnect, SE Series
    • Order option SI-AUX-RELAY

Typical application is forced air plenum heater, WarmFlo, electric furnace with a Mini-Boiler in the same building. The Mini-Boiler blue and blue/wh contact points are routed to the COM and EL terminals as outlined below.

Contact us with questions or for more information: