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Posted By: NJI reylay controled water heater-break a leg - 10/21/05 02:39 AM
Hello there could use your thought. 240v water heater. lowvoltage relay(24v)controled by night rate switch. The unit is a new instal yet plumber would not hook it up because reylay box seemd to be shorted out. It wasn't, isn't , had at one time..anyway. Reylay makes contact nicly..solid thunk when it comes in. loses continuety between terminals when power feeding it is off. like it should..n/o contacts. now hers's the problem: - When I conect line voltage it passed it right through as if it was on. I can turn it on you can hear the coil pull in...turn it off...still has power. took it apart. not even corroded, shinny. no continuety between terminals, coil is fine, around 34 ohms. no continuety to any of the terminals.

WHAT AM I MISSING.....GOT TO GO FIX IT TOMARROW MORNING. maybe i just need to sleep on it. thankyou for your time
Posted By: e57 Re: reylay controled water heater-break a leg - 10/21/05 02:57 AM
"When I conect line voltage it passed it right through as if it was on."
Are you sure it disconnects all phase conductors? It may just open the circuit on one side.... The voltage you see may be from there other side of the circuit.
Posted By: NJI Re: reylay controled water heater-break a leg - 10/21/05 03:19 AM
yes your right it opens( or is suposed to open) one leg. one leg is continuously on..the other brocken by this reylay. but it never gets brocken reylay on or off? get a new reylay even thouugh it tests out just fine? seems like just shooting the dark to solve a problem
Posted By: BigB Re: reylay controled water heater-break a leg - 10/21/05 03:54 AM
Are you getting 240 when the relay is open?? If it's only 120 then it's like e57 said, it's the voltage from the other side of the circuit passing thru the element and appearing on the other load terminal of the relay, which is normal.
Posted By: NJI Re: reylay controled water heater-break a leg - 10/21/05 01:19 PM
well, tested each side(terminal on the reylay) to ground..120. the one thing I didn't do was look at the voltage between them. your right I should have 240, would be a different leg. this is next on the list this morning, had to grab some parts here and thought i'd check with you all for your input. thankyou. i'm gonna go cheeck it out
Posted By: pauluk Re: reylay controled water heater-break a leg - 10/21/05 01:22 PM
Hi,

Where/how are you actually measuring the voltage and what are you using? If you're at the heater terminals with a high-impedance meter you could still be getting a reading due to capacitance.
Posted By: NJI Re: reylay controled water heater-break a leg - 10/21/05 01:34 PM
the element will create compacitence? I was measuring about five feet away at a reylay box. 240v in- one leg straight through- the other is supposed to be brocken by the reylay. it was hot on both sides of the reylay terminal. from each terminal to ground i had 120v. i didn't check between them, didn't even occurre to me, should i still be getting the same reading there as at the element, if all is working correctly
Posted By: NJI Re: reylay controled water heater-break a leg - 10/21/05 01:36 PM
oh ya, using a greenlee clamp-on voltage meter. i would have to go to the truck to give you the numbers. quality meter
Posted By: BobH Re: reylay controled water heater-break a leg - 10/21/05 07:37 PM
The voltage you're seeing is from the same phase more than likely. The voltage is feeding from the unbroken phase, passing through the heating element and then back to the relay. This is normal.
if you lost a leg, you could still get 120 from both legs. do you have 240 at the thermostat?
I often have to remind one of my guys to chack line-to-line as well as line-to-neutral when troubleshooting services.
Wnen you are checking a switch or fuse, check across it. You should see zero if it is closed and full circuit voltage if it is open, assuming down stream load is connected.
Posted By: NJI Re: reylay controled water heater-break a leg - 10/23/05 02:00 AM
hello, long couple of days here..havn't had the chance to get back to you
yes...the feeding through the element was the result of my reading voltage. re-instaled. workes perfectly. sometimes you just need a second opinion from time to time to help process. When you work alone sometimes the hour get to you...the thought process gets kind of fogged thnks for the quick help!
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