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Author Topic: MySensoring' an Intermatic EH40 Water Heater Timer  (Read 2393 times)

Offline ServiceXp

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MySensoring' an Intermatic EH40 Water Heater Timer
« on: September 08, 2014, 08:00:30 pm »
I figured I would post this here for those who don't frequent MySensors.org

Complete Project Page With Pictures and Everything..  :P

Project Complete! My EH40 has now been 'MySensored'

 This was a  fun  project, and I learned quite a bit during the process and I was able to accomplish all my goals.

Goal Recap
1) Remotely lockout the EH40's schedule.
2) Remotely Activate the EH40 Relay.
3) Locally override_to_On, Both Vera and the EH40 schedule (Button)
4) Remotely acquire water heater's tank temperature.

Final Components Used:
1) Arduino mini 5V
2) Dual Relay 5V]
3) Couple of pcb's
4) Screw Connectors
5) Push Button
6) Temperature Sensor
7) Radio
8.) Step Down Module
9) Fused Rocker Switch
10) Transformer I wound up going with one of these over the Ebay China option. Just felt more comfortable with this.
11)Project Box

Misa: Resisters, 47uF cap for the radio, wires and lots of solder and hot glue.

Final EH40 Wire Configuration

SEE PICS HERE IN MYSENSORS.ORG THREAD

1) Red - 1.5vdc directly from EH40 Batt.
2) Black (Yellow) GND
3) Blue (Blue) Input
4) Yellow (Blue) Output

Transformer Assm: Board

SEE PICS HERE IN MYSENSORS.ORG THREAD

The output seem stable enough (using a volt meter) I didn't use any post filtering. (EDIT: I added a 47uF cap to the output and 0.1uF to Relay, and Sensor VCC and GND)
All connection under pcb is covered in a thick layer of hot glue to help prevent any shorts.

EH40 Connection Board

SEE PICS HERE IN MYSENSORS.ORG THREAD

Main Control Board

I forgot to get pictures of the top, but here is the messy bottom..

SEE PICS HERE IN MYSENSORS.ORG THREAD

EH40 Connection Board Mounted In Box

SEE PICS HERE IN MYSENSORS.ORG THREAD

Using a Dremel; cut a slot out, then hot gluing to bottom of box.

Dual Relay Mounted

SEE PICS HERE IN MYSENSORS.ORG THREAD

It was a perfect fit.

Push Button and LED (Wired Relay Contacts)

SEE PICS HERE IN MYSENSORS.ORG THREAD

Top relay is #1 (Lockout); 2nd is #2 (Override)

1)Relay #1 -- Blue Wire -- Output to NC
2)Relay #1 -- Yellow Wire -- input to COM

3)Relay #1 -- Blue Wire -- Output NC JUMPED to COM of Relay #2

4)Relay #2 -- 2 Red Wires (One from EH40 and the other for battery monitoring on Main Control Board) -- Output to NO
5)Relay #2 -- COM JUMPED to Relay #1 NC

Fused Power Switch and Socket

SEE PICS HERE IN MYSENSORS.ORG THREAD

500ma Fuse with all exposed connection covered in hot glue.

Transformer; Relay; EH40 Connection and Main Board

SEE PICS HERE IN MYSENSORS.ORG THREAD

I tried to keep the High Voltage section isolated from any of the low voltage section as best as possible.

Completed Project Connected to EH40

SEE PICS HERE IN MYSENSORS.ORG THREAD

EH40 Connection

SEE PICS HERE IN MYSENSORS.ORG THREAD

115vac Connection

SEE PICS HERE IN MYSENSORS.ORG THREAD

EH40 Has Control and running it's schedule

SEE PICS HERE IN MYSENSORS.ORG THREAD

Vera (Remote) has EH40 Schedule Locked Out (Water Heater Off)

SEE PICS HERE IN MYSENSORS.ORG THREAD

Vera (Remote) has EH40 Schedule Locked Out but Override button is active (Water Heater On)

U.S.A Vera 3


Offline ServiceXp

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Re: MySensoring' an Intermatic EH40 Water Heater Timer
« Reply #2 on: September 08, 2014, 08:49:04 pm »
Your missing 2 things:

1) I already owned the EH40
2) I wanted to see if I could pull it off using the MySensors library.

The added benefit for me... I learned a lot throughout the project and it was quite fun.
U.S.A Vera 3

Offline integlikewhoa

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Re: MySensoring' an Intermatic EH40 Water Heater Timer
« Reply #3 on: September 08, 2014, 08:52:57 pm »
Your missing 2 things:

1) I already owned the EH40
2) I wanted to see if I could pull it off using the MySensors library.

The added benefit for me... I learned a lot throughout the project and it was quite fun.

I actually figured that had to be the case. I'm just starting to play with Arduino myself and finding it quite fun. Usually my fun doesn't turn into being so helpful but sometimes it does. LOL

Offline ServiceXp

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Re: MySensoring' an Intermatic EH40 Water Heater Timer
« Reply #4 on: September 22, 2014, 03:01:42 pm »
Update:
  Wind up having to buy a oscilloscope to try and diagnose a problem I was having and wound up reworking the transformer board a little.  I installed 5 caps in an attempt to clean up the output.
4.7uF/400V Cap between pins 22 and 26 on transformer. (electrolytic)
470uF/50v Between 5vd Output (electrolytic)
47uF/50v Between 5vd Output (electrolytic)
10uF/50v Between 5vd Output (electrolytic)
.1uF/ (ceramic)  Installed at the screw connector on the main board (for best results)
U.S.A Vera 3