Go Back  DoItYourself.com Community Forums > Electrical, AC & DC. Electronic Equipment and Computers > Electrical - AC & DC
Reload this Page >

Need help wiring an Intermatic WH40 water heater time switch into the system

Need help wiring an Intermatic WH40 water heater time switch into the system

Reply

  #1  
Old 01-31-13, 04:29 PM
Member
Thread Starter
Join Date: Jan 2013
Location: USA
Posts: 3
Need help wiring an Intermatic WH40 water heater time switch into the system

Hi folks;
First let me say that wiring, especially 240V has never been my favorite subject hence my need for help with the title install. The first thing I always do is turn the power off at the house breaker panel. And with 240 I turn off the system breaker to make sure there is no power available anywhere to fry me. I learned my lesson as a young Warrant Officer Helicopter Pilot flying AH-1G Cobras in the Army.

To the issue:
The house electrical wires are a ground (bare), a white and a black. They connect to the water heater with the black going to black and the white going to red and the ground to a ground post which has the green ground wire from the water heater attached. I understand that the white is considered the same as a red for the purpose use in a water heater.

The water heater is a GE using a 240/208 with a max of 4,500 watts.

The WH40's wiring diagram shows the 6 attachment points in the actual unit and describes each screw's wire(s):
So, with that here goes my assumptions: (And the help I'm requesting)[/FONT]

-GRD is self explanatory, the rest is supposition on my part and we all know what assume means.

-Below that is the Neut (white) post. I assume that since there is no white wire in the water heater and the house white wire is connected to red that I don't put anything on this post. Is that right?

-To the right are the next 4 wire connection posts, numbered 1 to 4 with a separation between 2 & 3.
-Post 1 would get the white wire and 3 would get the black wire, both from the house wiring.
-Post 2 would get the red wire from the water heater and 4 get the black wire from the water heater.
Am I even close? I appreciate any help you folks can provide. Cheers, Frank
 

Last edited by ray2047; 01-31-13 at 04:51 PM. Reason: Remove un-needed font.
Sponsored Links
  #2  
Old 01-31-13, 04:57 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 33,042
Welcome to the forums. In the future compose your replies in the forum editor. I had to remove outside formatting in your post that was reducing the apparent size of the font.

As I am reading the diagram no neutral needed, line to 1 and 3 - 2 and 4 to load.

 

Last edited by ray2047; 01-31-13 at 05:26 PM.
  #3  
Old 01-31-13, 05:12 PM
Member
Thread Starter
Join Date: Jan 2013
Location: USA
Posts: 3
Thanks, I didn't realize I had done that.

Does your comment on the wiring mean that my meandering assumptions are correct?
 
  #4  
Old 01-31-13, 05:29 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 33,042
Yes, but by code that white wire should have been remarked red, black or any color but green or gray by banding it with colored tape or recoloring it on both ends with felt tip marker.
 
  #5  
Old 02-01-13, 08:00 AM
Member
Thread Starter
Join Date: Jan 2013
Location: USA
Posts: 3
Thanks Ray. I will do that as I have red tape and markers. Also, your schematic is much easier to understand than the one that came with the unit. It is labeled 120/240 and has 4 connections going either way. Anyway, thanks again, I always try to do things the right way. Checking with an expert is one sure way. Cheers, Frank
 
  #6  
Old 02-01-13, 08:24 AM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 33,042
That was from an online PDF. Be sure my schematic matches your timer. http://www.google.com/url?sa=t&rct=j...xzMNMmTSZ4djIA
 
  #7  
Old 02-01-13, 12:04 PM
Banned. Rule And/Or Policy Violation
Join Date: Jan 2010
Location: KS
Posts: 1,896
If it has 6 terminal screws (not counting the ground screw) and says 120/240v on the unit, then it is not a WH40. WH40's (says "Little Gray Box" on the cover) are 208/240v only unless you change the clock motor.

Also, I must ask, do you currently have (or are you willing/able to change to) "Time of Day" metering from your electric company? If not, then having the timer on the water heater will save you exactly nothing. In fact it'll cost you more, and here's why.. First of all there's the $50 you spent on the timer. Then, it doesn't matter if you are maintaining a temperature constantly or letting it cool and then heating it back up, you are still using energy. However, due to the inefficiency of turning the electricity into heat and transferring heat to the water, it takes slightly MORE energy to bring a cooled tank back up to temp than it does to keep it at temp.

So basically the water heater timer is designed to take advantage of "Time of Day" metering, where the 'peak' rate (usually 8am to 8pm M-F) is much higher than the 'off peak' rate (8pm-8am, plus weekends). Instead of using the higher priced 'peak' power to maintain the temp, it allows the tank to coast until the 'off peak' rates kick in and then the timer kicks on and it heats back up using the cheaper power.

Most people don't realize this when others tell them that putting the water heater on a timer can save them money.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes