Controlling an Electric Hot Water Heater with an Insteon EZIO4O Four Output Relay and Contactors

The electrical system in our present house is somewhat out of the ordinary - 400 Amp services, three separate 200A breaker panels, a whole house disconnect switch, a generator transfer switch, and one of the 200A panels is the generator emergency panel. In addition to the three 200A panels, there are two relay panels - one associated with the generator emergency panel which has 26 light circuits and has since been converted to Insteon with Insteon switchlinc switches and relays, and one panel with six 60A contactors, and about 8 light circuits, associated with one of the other 200A panels.

Contactors / Lighting relay panel associated with 200A breaker panel - circuit feeds enter through the nipple on the bottom right corner of the panel. Control wires enter in the top left.

The project for today was to add Insteon controls for four of the 60A contactors. I decided to use the Smartenit EZIO4O four output relay interface. The EZIO4O can switch up to 120VAC or 24VDC at 0.5A on four output relays, and can be controlled by the ISY994i Insteon controller. The contactors in this panel all have 120VAC coils - so I decided to use 120VAC as the control voltage and switch 120VAC directly with the EZIO4O.

Cabling was quite simple - I installed a standard electrical outlet in the device frame, to accept the plug in EZIO4O. I daisy chained a 120VAC control voltage to all the output positive connections, and then cabled the contactor coils with the EZIO4O negative connections. The EZIO4O lets you connect to both normally open and normally closed contacts. I decided to use the normally closed contacts - so that activating a relay on the EZIO4O would turn the circuit, and the contactor off. I wanted this system to fail closed - so that in the event of a control problem with the Insteon controller - I would still have hot water. 

Black wires are 120VAC Line feeds to the relays. Orange wires are the 120VAC load lines to the contactor coils. 

Once it was all wired up - I did some quick tests with the Mobilinc app on my phone - all the contactors switched virtually instantly when commanded by Mobilinc, and now I can work these devices into energy management programming. One of the circuits is my 60 gallon hot water heater. Another circuit is a steam generator for the master bathroom shower. The third circuit switches two circuits of 230VAC supplemental electric baseboard heating in the basement. The fourth circuit is unused for now.

My plan now that everthing has been connected and tested is to work these controls into the house vacation mode - when in vacation mode - turn off the hot water heater, the steam generator and the supplemental auxiliary heating in the basement. Quite often the kids will turn on the supplemental heat in the playroom - I'll be able to add a program to ensure it's turned off at night to help conserve energy. If you live with a service that charges peak electricity charges - then you could force the heating of your hot water heater in off peak times to save on your electricity rates. 

Steam generator circuit - top contactor - 50 gallon hot water heater - bottom contactor.

I have a "before" photo of this panel - what it looked like before I did the Insteon conversion two years ago. The contactors were always there, but instead of the Insteon switches, the panel had GE lighting control relays, which were controlled by an Industrial programmable logic controller (PLC).

6 Lighting relays, 5 Contactors - Original Setup for this Panel. Wires in the left hand compartment were the control wires coming from the PLC outputs.