# Hot H20 electricity consumtion metering

Discussion in 'Electronic Basics' started by rob, Oct 16, 2004.

1. ### robGuest

Hi...I need to determing how much electricity a solar water heater is
replacing. The solar heater preheats the water before it enters the
electric heater...I need a cheap solution to measuring the electrical
usage over a months time period....I am thinking an hours meter
somehow wired might work....Any suggestions?????

Thanks Rob

2. ### Bob MastaGuest

This should be pretty simple since in theory you could
just put an electric (not electronic) clock across the element.
But the element runs on 220 in most installations, so
you'd need a transformer or something. And in most
electric water heaters there are actually 2 separate
elements, one at the bottom that does most of the
heavy lifting, and one at the top that kicks in if the
cold-water line in the tank reaches that high under
heavy use. So you'd need two separate clocks and
transformers.

In my own case many years ago, I wanted to see the
effect of super-insulating the tank. I just hooked
little NE2 neon bulbs across the elements, each with a
CdS photocell next to it and wrapped in electrical
tape to block stray light. Used a chart recorder I
happened to have on hand to monitor activity.
If you have some sort of recording device, this
approach may work for you as well.

Best regards,

Bob Masta

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com

3. ### cornytheclownGuest

You can purchase a watt hour meter and meter base for that purpose
from the local electric utility. Or call a local electrician.... try
ebay...

4. ### BobGardnerGuest

I need to determing how much electricity a solar water heater is
The water heater is either on or off. If you could get a 220V clock, you could
gator clip that onto the heating element and see how many hrs a dat its
running. Quick... how many BTUs in a KWHR? ans: 3412

5. ### robGuest

Yup...that seems to be simplist\cheapest....Thanks all

6. ### Nick HullGuest

The water heater is either on or off. If you could get a 220V clock, you could
gator clip that onto the heating element and see how many hrs a dat its
running. Quick... how many BTUs in a KWHR? ans: 3412[/QUOTE]

Since 220 volts uses 2 110 volt legs a 110 volt clock can be made to
work. Use analog not digital.