Using 30Amp Timer to Swith Power Source

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  #1  
Old 08-04-06, 09:12 AM
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Using 30Amp Timer to Swith Power Source

Hello,

Is anyone aware of a way that a timer may be wired to switch between power sources?

For example, I have a dehumidifier that runs 24/7 and I would like to provide an outlet that uses the off-peak electrical supply during the portion of the day that this is available and use the "regular" electric during the remainder of the time.

Any help is appreciated! Thanks!
 
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  #2  
Old 08-04-06, 09:28 AM
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I never knew that off peak electric came into the building over a seperate set of wires then the regular electric. I thought that peak/off peak was a function of the meter and time of day, but used the same electrical supply wires.

Can you explain this concept further?
 
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Old 08-04-06, 09:34 AM
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JWhite,

Thanks for your reply.

At my residence, there are two separate meters on the outside of the house: one for "off-peak" and the "regular" one. The off-peak meter goes to a 60A circuit breaker box. The regular service goes to a 200A circuit breaker box. Sorry if I don't have the terminology correct.
 
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Old 08-04-06, 09:37 AM
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I should add that the off-peak service is billed at 50% of the rate of the regular service but only available during certain times of the day. It is this characteristic that I want to take advantage of.
 
  #5  
Old 08-04-06, 11:27 AM
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How do you switch the rest of the loads in your house?

Does half your house go to one panel and the other half to the other panel. This is a totally new set up to me. Where do you live?
 
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Old 08-04-06, 12:42 PM
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Actually, the only appliance currently using the off-peak meter is an electric hot water heater. The remainder of the house uses the regular service.

I live in Mongomery County, PA. There's a fixed fee for the off-peak service, and additionally, the electric company (PECO) no longer installs new off-peak service (though existing service is grandfathered).
 
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Old 08-04-06, 12:45 PM
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Use a contactor with a Normally-Closed (NC)contact and a Normally-Open (NO)contact.

During the "peak" period, the load is connected to the peak meter thru the NC contact.

At the start of the "off-peak" period, a timer will energize the contactor, which opens the NC contact and closes the NO contact. The load is now connected to the Off-peak meter thru the now-closed NC contact.

Be sure there is ZERO volts , not 220 volts,between the conductors from the two meters. 220 volts = one conductor conncected to Service leg "A", and the other to Service leg "B". "A" and "B" are the two "live" Service Conductors.

Good Luck, & Learn & Enjoy from the Experience!!!!!
 
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Old 08-04-06, 12:55 PM
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PATTBAA good sugestion, but will you warenttee it when for some reason it does not work correctly. I know it works electrically, but are you sure that any given fault will not be catostrophic?

The only legal thing here would be a rated transfer switch which would probalby cost about the same as 10 years of use.
 
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Old 08-04-06, 01:15 PM
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I would think that utilizing an automatic transfer switch integrated with a time clock would serve the purpose. A 100 amp one (I haven;t actually looked at the specs or design) was found for $430. If you have a 100 amp panel, you could swicth over the entire panel load.

a 30 amp one was $73.

concerning jwhites concerns: since th OP actually is not utilizing a different service, as long as the same phase is routed through the contactors paatbaa detailed, there could be no catastrophic failure. Even if both contacts welded closed, it would merely connect two of the same phases together. While this would not be optimum because you would effectively have one device fed from two sources, it would definately be less than spectacular in its results.(pattbaa actually already addressed this situation with the a phase b phase not 220 volts info)
 
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Old 08-05-06, 08:56 AM
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What exactly are the "load-specifications"? -- the voltage, current, and wattage ratings of the controlled load?
 
  #11  
Old 08-05-06, 06:23 PM
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Seems like a lot of work for just a hot water tank,, Why not just get a timer for the tank to shut it off during the night and for hours that your not home?
 
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Old 08-05-06, 06:28 PM
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Originally Posted by Navydad1
Seems like a lot of work for just a hot water tank,, Why not just get a timer for the tank to shut it off during the night and for hours that your not home?

You are missing the point dad. The OP wants to utilize the less expensive electricity when it is available. Apparently the way the OP's metering system works, he cannot simply utilize the meter for the discount rate all the time but only during the allowed discount times.

Also, the OP already has the water heater on the discount system, he would like to add the dehumidifier as well.
 
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Old 08-05-06, 06:39 PM
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betthefarm. are you saying that during peak times, your water heater is turned off?
 
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Old 08-06-06, 04:20 AM
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I did miss the point,, Swear I get dumber by the day
 
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Old 08-06-06, 05:25 AM
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Don't try to use a 30 amp timer. PAT I think it was suggested the more appropriate method, augmented by Nap. Any small timer, possible powered by a 240/24v AC transformer can drive a contactor of any size. The contactor does need to be a DPDT switch (transfer switch) in order to accomplish what you want. However, if you do elect to switch the entire panel I would strongly suggest a transfer switch with 240v coil. I'm not even sure they make a 100 transfer switch with a low voltage coil.

If you are unsure of how to do it once you have the parts I would strongly advise the use of a licensed electrician. And, switching the entire 100a panel will pay for itself in less than a year I would think...

I'm wondering, what keeps you from running everything off the 50% meter all the time? Does it go dead at certain times? If so, then use the power from that panel to drive the transfer switch. Normally closed would get power from the main panel, normally open would get power from the 50% panel, and not timer is necessary.
 
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Old 08-06-06, 07:45 AM
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Originally Posted by mdtaylor
I'm wondering, what keeps you from running everything off the 50% meter all the time? Does it go dead at certain times? If so, then use the power from that panel to drive the transfer switch. Normally closed would get power from the main panel, normally open would get power from the 50% panel, and not timer is necessary.

Sorry md, I messed you up. I missed where the OP stated he has a 200 amp service. I subsequently tossed in the possiblioity of it being 100 amp.


I also wonder about the situation of running from the 50% meter all the time. How would the poco differentiate or as you suggest; does it get killed during "peak" times??
 
  #17  
Old 08-07-06, 04:40 AM
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Before you do this, you need to make sure that you are allowed to do this.

Years ago, they used to wire some residences so that during peak hours of the day, 4:00 to 7:00 in the afternoon (peak hours for residences) certain appliances would not work. One in particular was water heaters, or more specifically half of the water heater. This was to allow more power for people to use their electric ovens to cook dinner.
 
  #18  
Old 08-15-06, 03:57 AM
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Sorry that I've been remiss in responding. To answer what a few of you asked, yes, the OP meter goes "dead" during certain times of the day (the time differs in the summer and winter). Therefore, the electric water heater is not powered during certain times of the day (this hasn't been a problem thusfar).

Thank you all for your suggestions. For some reason, I thought that this would be a relatively easy feat to accomplish. I was not aware that the off-peak feature was so unique! Thanks again!
 
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Old 08-15-06, 10:02 AM
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Originally Posted by racraft
Before you do this, you need to make sure that you are allowed to do this.

Years ago, they used to wire some residences so that during peak hours of the day, 4:00 to 7:00 in the afternoon (peak hours for residences) certain appliances would not work. One in particular was water heaters, or more specifically half of the water heater. This was to allow more power for people to use their electric ovens to cook dinner.
Bob is correct. I won't "BetTheFarm" on this, but I believe the purpose of this peak/non-peak usage system relies on the fact that this particular appliance will not be used during the peak periods. By switching the appliance to the other panel, you would be defeating the system. I would bet that the power company (and the law, for that matter) would not be very happy about it.
 
  #20  
Old 08-15-06, 03:39 PM
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Originally Posted by Randy Mallory
Bob is correct. I won't "BetTheFarm" on this, but I believe the purpose of this peak/non-peak usage system relies on the fact that this particular appliance will not be used during the peak periods. By switching the appliance to the other panel, you would be defeating the system. I would bet that the power company (and the law, for that matter) would not be very happy about it.
I would be surprised if it was against the law. Would it be against the law for me to plug the dehumidifier into an OP metered outlet during OP times and manually unplug it and plug it into a peak metered outlet during the time that the OP is unavailable? Granted, it would be a royal pain in the butt, but illegal...
 
  #21  
Old 08-15-06, 07:03 PM
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You'd have to check your tarriffs form your utility to see if the OP service is only for your heating, or genral use. By bet is the former.
 
  #22  
Old 08-16-06, 04:39 AM
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BetTheFarm,

I live in VA, and have been participating in a similar plan here for years. Instead of a separate panel, my water heater is hooked through a switch which is controlled remotely by Dominion Power. Whenever peak demands exceed a certain point, they turn off my water heater. Instead of metering that device and letting me use it at a reduced rate, they credit my electric bill each month with a fixed amount. Either way, if I defeated the circuit, which is very easy to do, I would not be honoring an agreement I made with them when they installed the switch. They are, in effect, "paying" me not to use the water heater during peak periods.

The power you receive through your off-peak panel comes from the same source, and costs just as much for the power company to produce. By switching it off during peak periods, they are attempting to avoid costly capacity upgrades, that would only be needed a small part of the day. In any case, their efforts would not work at all if everyone defeated the system by switching to the regular panel.

Bottom line is that the power company is "paying" you, by providing discounted power, to not use the devices hooked up to the off-peak panel during peak use periods.

In any case, a call to your provider would clear this up. If you do call them, I, and all others participating in this forum, would be interested in hearing what they say.

Thanks,
 
  #23  
Old 08-16-06, 05:06 AM
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What is confusing to me is that I have never heard of these setups feeding two separate panels, each capable of multiple loads.

I am only familiar with the timed off peak feed going to the bottom element of an electric water heater.

Please do determine exactly what you have and what you can and cannot do from eeach feed.
 
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Old 08-16-06, 05:44 AM
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Hi Randy,

Thanks for your comments. You have an interesting perspective on the situation; however, I think that it is an inaccurate characterization to say that the electric company is paying me to use the OP service (perhaps this is why you put the word paying in quotes). To be clear, the money has only gone in one direction in my relationship with the electric company. It is true that one pays less for OP service, but one is not payed to used it.

My perspective is that the energy company introduced this mechanism to encourage a higher demand for electrical consumption during OP times by reducing the price of electricity. Consequently, I would like to puchase as much of my electrical needs as possible at this bargain price. When the bargain price is not available, my electrical needs can only be met by purchasing at the regular price. It is likely that their intention behind this mechanism is to shift electrical consumption from one period of time to another (and thereby eliminate the need for costly capacity upgrages). However, the only terms by which I am bound are as follows: the off peak service is not available during certain times during the day. I do not intend to make any modifications that would bypass that obligation (I have heard of individuals rigging their OP meter to perform 24/7).

I do not have a contractual or moral obligation to limit my regular electrical use and intend to utilize the two electrical services available in a way that will minimize the cost of the services. It is not my responsibility to reduce the electric company's need for capacity improvement.

Frankly, I have dismissed the idea of using a timer to switch between peak and OP meters because it is too much trouble. However, I maintain that if I did so, I would not be afoul of any contractual or "honor" issues. I have previously contacted the electric company but the knowledge of the customer service was extremely low. The first person to whom I spoke asked me what off-peak service was. Her manager did not know of any conditions other than the time availability surrounding OP service. I have not pursued the issue further.

If anyone is curious, the following excerpt was taken from the electric company's website:

*****
Only appliances hooked up to the OP meter will receive the special OP rate. All other usage will be billed at the rate for either R or RH usage.

Typically, people have hooked up air conditioners, hot water heaters, clothes dryers, swimming pools, hot tubs, etc. to these meters. Appliances connected to an OP meter cannot draw power for certain hours of the day: between October and May from 4:30pm 6:30pm. and June-September from 1:00pm 7:30pm. Hot water heaters usually have sufficient capacity to provide hot water for a household even when the power to the heater is off.

For some people, it is worth changing their electric lifestyle to enjoy big savings (like doing laundry only at night.) For others, the OP meters are just not feasible.

*****
 
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Old 08-16-06, 05:46 AM
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Originally Posted by racraft
What is confusing to me is that I have never heard of these setups feeding two separate panels, each capable of multiple loads.

I am only familiar with the timed off peak feed going to the bottom element of an electric water heater.

Please do determine exactly what you have and what you can and cannot do from eeach feed.
racraft,

I can confirm that their are two separate meters feeding two separate panels. The bill presents the usage "read" from each meter.
 
  #26  
Old 08-16-06, 05:50 AM
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bob,

I grew up in the small town of Louisa, Virginia. Before I moved to the big metropolis of Yorktown, Virginia, I was an electrical contractor, licensed to do business in Louisa County, which includes the town of Louisa. I left Louisa in 1976...yeah, I'm getting old.

In 1986, we had a "cabin" built on Lake Anna, which is in Louisa county. The contractor said he had to install two panels....two 200AMP. 40 space panels. Of course, I wasn't happy about paying for all that. Only one breaker was ever installed in the second panel. It was for the heat pump. It turns out, the poco had plans to meter any form of electrical heat. They never implented the plan, however. We also have a dual meter base, with only one meter installed.
 
  #27  
Old 08-17-06, 03:54 PM
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IMO, you would be afoul of at least the honor of the system. The logic is to make you run those appliances *only* at those off peak times, by selling you cheaper electricity at those off peak times, not by just providing a cheaper off peak rate you can use at your whim.
 
  #28  
Old 08-17-06, 04:45 PM
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If we're offering opions, here's mine for what its worth...In your defense "bet the farm" You are under no contractual, moral or ethical obligations to the poco. If you want to run power to the rest of the house off of the "OP" meter all you have to realize is that you won't have power during the off peak times...big woop. What i would be inclined to do ( if i were trying to to attempt your idea would be to go with the original idea of the contactor/ timer. it doesn't sound like you have the elctrical know how to save yourself any money...( i think i have the know how but i doubt i would save myself any money) The transfer switch idea would work as well i believe but thats alot of money for what you are intending.

quick fix...run two receptacles to the dehumidifier one from "OP" and one from "regular" and then just switch the plug by yourself...tedious yes i know but easy fix.

Like everyone else i am curious as to the result of this endeavor let us know how things work out.
 
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