looking for some help on if this box is overloaded

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  #1  
Old 07-03-14, 01:37 PM
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looking for some help on if this box is overloaded

We are moving into this rental and when the thankless hot water heater is turned on its the two 60 amp breakers at the bottom the lights dim and kind of fliker. We are not using it yet as we haven't fully moved it I just want to get some advice before I call someone out to look at setting it right if it's possible and making the land lord pay for it. Thanks
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  #2  
Old 07-03-14, 01:40 PM
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Welcome to the forums.

In my opinion, the issue isn't the panel being overloaded it's trying to run a tankless water heater on only 150 amp service.
 
  #3  
Old 07-03-14, 02:43 PM
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I agree. 60A is quite a load. There really isn't a way to improve the situation without possibly going to a 200A service.

Even then.... if the service to the street is long and undersized....... increasing to 200A may not make a noticeable improvement.
 
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Old 07-03-14, 03:05 PM
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The instant water heater isn't drawing 60 amp. It is drawing 120 amps. I see two 60 amp breakers. Is there also a storage water heater? I see a breaker for one at the top?

Since this is a rental I'd run not walk away from it. Ii would cost the owner thousands to bring the electric up to what is needed and I can't see that happening. Or is there a second electrical panel?
 
  #5  
Old 07-03-14, 03:36 PM
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The panel isn't quite labeled correctly but you're right about the 2x60A breakers Ray.
 
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Old 07-03-14, 04:15 PM
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If there really is a storage water heater still in place then I'd say not using the instant water heaters might be a good idea.
 
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Old 07-03-14, 11:09 PM
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Sorry for not being more clear yes the thankless is 2x60 so 120 and no there is no other water heater also the sad thing is he just spent god knows how much rewiring the entire house from the old cloth insulated stuff to modern romex. As well as whole new run from street and new metrer and main cut off outside so other box other than the main disconnect at the meter. The problem seems to be lack of planing on his behalf of what was going into the house. Seems to me a lack of knowledge on the behalf of the ones doing the work.

What would be needed to bring it to a 200 service?

I would guess new new run from street if the gauge isn't big enough or at least up the gauge from meter to box if the meter is capable of 200 and how would I know what the supply from the meter/street is capable of would that be a simple call to the utilities?

Sorry for all the questions but we are kind of already a$$ deep in this deal doesn't seem like much chance of backing out without losing at least our deposit and so on with what money we have put into other things for this house. Would maybe rearranging what is in the box to maybe balance the load help any. Cause when the "plumber" was putting it in he had both 60 amps on one side and I asked if it would be better to try and even the load cause it seemed like a lot of load for one side. Thanks for the warm welcome and all the help so far guys
 
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Old 07-03-14, 11:44 PM
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Actually if the back up heat is electric and the stove electric 200 amps may not be enough. Your at 150 amps just with the dryer and water heaters. Heat strips on the heat pump backup could be 40 amps or more. You are going to need to do a load calculation.

It would probably be cheaper to use the existing panel and pull out the instant water heater and install a storage water heater.
 
  #9  
Old 07-03-14, 11:58 PM
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Yea I was afraid of that and yes stove is electric as well as heatpump with electric backup. Is there a site or formula for doing the calculation? It worries me cause I also have my tools (air compressor drill press so on) them my toys/work I am a computer/small electronics person LV is more my thing not 120/240 lol. And to top or off idk of anywhere in this house to stick a storage type water heater.
 
  #10  
Old 07-04-14, 12:03 AM
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I also remember reading somewhere that you should go by watage not amperage? as one can move so to speak and never load a box to more that 80% or total. Idk if that makes sense or not. Correct me if I am wrong please I am here to learn I feel that if I don't learn at least one thing a day not doing my job.
 
  #11  
Old 07-04-14, 06:46 AM
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I suspect your panel labelling is incorrect and that the 2P 60A breaker at the top right is actually your airhandler with 10 KW electric heat (probably about 45-48 amps) to back up the heat pump. How big is this house (sq feet)?. The two 60 amp circuits to the tankless water heater will not draw 60 amps each, but probably closer to 48-50 amps. That being said, the 150 amp service is overloaded and the actual load could be right at the edge of the capacity of a 200 amp service. Yes, a load calculation is badly needed. You need to know the actual wattage of the tankless heater and the electric heat to do a calculation.
 
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Old 07-04-14, 08:19 AM
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Here are two calculator: Single Family Dwelling Load Calculator and another: http://www.docstoc.com/docs/97696973...lt-Enterprises The second link requires joining and downloading but is a very reputable source.
 
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Old 07-04-14, 08:48 AM
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Sorry yes I ment to say it is improperly labeled not sure what the people who were doing some of the work here were thinking. I am going to go in this weekend and test and properly label everything. I will try and find the wattage for both no for what ever reason the 50 amp at the top right that says "water heater?" Is the stove the a/c and this was another question I was concerned with is that the a/c is divided between two 30's.

And the house is around 900 sq ft.
 
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Old 07-04-14, 10:43 AM
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for what ever reason the 50 amp at the top right that says "water heater?" Is the stove the a/c and this was another question I was concerned with is that the a/c is divided between two 30's.
I mistook the 50 amp 2 pole at top right for a 60 amp, but it still could be electric emergency heat unless maybe the heat pump is backed up by a gas furnace. Most electric ranges have either a 40 or 50 amp circuit and most electric dryers use a 30 amp 2 pole circuit. I also suspect the separate single pole breakers marked heat pump are not correct, I would look for a 2 pole breaker to supply it.
 
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Old 07-04-14, 09:52 PM
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Yes sorry if my post before was unclear the 50 is the stove and the a/c heat pump and airl handling unit is divided between 2 30 amp double polls. Meaning I have one 30 double poll I can turn off and the heat pump will go off and another 30 double poll that will kill the blower and all inside. There is no gas wish there was in way and in others I'm glad there isn't.
The good news is I worked out the tankless is 27kw and 150 amp service is 36kw so armed with all your guys help and that knowledge we talked him in to swapping it out but he still wants tankless so he is going with a smaller unit now my question is how small.
 
  #16  
Old 07-05-14, 06:56 AM
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another 30 double poll that will kill the blower and all inside.
It's impossible to tell for sure without inspecting the furnace/air handler, but it sounds as if you have about 5 KW electric emergency heat. Usually if a house is tight and well insulated, you'll need about 10 watts per square foot for heat or in your 900 square foot house, 9 KW heat.
 
  #17  
Old 07-07-14, 10:35 AM
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This house is far from tight seeing as it can't keep it 72 when its 80 outside. I will be getting in the actic this week or weekend I hope to install my camera system so I will take a peek at the air unit to see what it is. Once again I want to thank everyone for all the help and if anything new turns up I will be sure to post it up.
 
  #18  
Old 07-07-14, 07:20 PM
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FYI - The "water heaters" is likely a single electric tankless unit. The circuits are commonly limited to 60 amps max so two are required.

Are you buying this rental property? Or are you just renting it? If you are renting it then none of this is your problem. As long as everything is properly protected, there should be little issue. I would however be sure to insure your property.
 
  #19  
Old 07-08-14, 03:06 PM
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Yes we are just renting but the owner lives in California and we are here in Georgia with the house have an agreement with the own to cordenate all repairs and to help keep the house up/make improvements. What you are saying doesn't make a whole lot of sence to me seeing as the tankless water heater and yes there is only one not two as the breaker box is mislabeled I will be sorting that out soon enough just been really busy. That one tankless is 120 amps or 2700 watts we are on 150 amp service which is good for 3600 watts. This is only the water heater not to mention stove,a/c,dryer, and then all my network/PC equipment.
I have not had a chance to see what the a/c draws wattage wise seeing as I have been to busy to get a a lader tall enough to get into the attic seeing as the only access for the attic is out side the house 20+ feet up. The only info I have a/c wise comes from the heat pump out side and all it says is max breaker 25/25 a d min breaker 20/20.

Not to mention this is my problem if the house burns to the ground from a overload box or we die in our sleep cause of a fire. So the whole it is not my problem attitude doesn't work and if that is your attitude then please do not comment.
 

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  #20  
Old 07-08-14, 07:56 PM
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The worst thing that should happen (if everything was wired and fused properly) is the 150 amp main breaker will trip because of too much current being drawn from your appliances. That is what the main beaker is for. My "not your problem" comment was referring to the fact that most locations only allow electrical work to be done by a licensed electrician, except if it is their home they are living in.

IIRC code only allows a maximum feeder of 60 amps to some appliances. So tankless water heaters use two 60 amp feeds. Your heaters maximum draw will be something less than the 60 amps the breakers are rated for. However, using 120 amps for an example, it would be 28,800 watts not 2700. (120amps x 240 volts = 28,800) Your 150 amp service is maxed at 36,000 watts, (150 amps x 240 volts) that is if all the loads are perfectly balanced. But you can see that with the tankless heater that only leaves you 7200 watts for everything else, and anytime somebody is taking a shower, the tankless is running full tilt.

The other thing to mention is was this panel inspected? If so, was the outside (meter socket, service drop, etc.) also upgraded? Also, did anybody contact the power company about if their feeders/transformer feeding the house are of adequate size for the addition of a tankless water heater?

IMO the tankless water heater needs to go. Based on your location, I would look into a hybrid water heater.
 
  #21  
Old 07-09-14, 10:46 AM
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Thank you for a much better and much more detailed response that is a lot more helpful.

Knowing that the work more than like is required to be done by a licensed electrician really helps my argument as I know the person who installed it is not as well as the guy who was sent out last night to look it over is not either.

The 2700 came off the data plate for the tankless not a calculation.

But if the feeder is not adequate would this not be a fire hazard?
 
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Old 07-09-14, 03:14 PM
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The tankless water heater is only 2700 watts? That doesn't sound right, is this a whole house unit or a point of use under a sink?
 
  #23  
Old 07-09-14, 06:54 PM
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Ha sorry type-o 27000 aka 27kw
 
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Old 07-10-14, 07:23 PM
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OK so the landlord is trying to find every way around this he wants to try and move the breakers around is this an option. I would assume not seeing as everyone on here has already said the box is overloaded he is just addressing the light flicker issue and not the power consumption issue it seems.
 
  #25  
Old 07-10-14, 07:54 PM
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27KW, that makes sense.

Moving the breakers will do nothing because it is a 240 volt load. It is drawing equally from both hots of the service.

It is fairly common for lights to dim when a large load kicks in. We have had other members who will report dimming lights when their house A/C kicks in, and that is mostly only a 30 amp load (although a motor will draw up to 3 times running current on start up)

My suggestion(s) to you are to have the power company come out and check their lines to the house. They will do this for free 24/7 if you tell them your lights are dimming. While they are there ask them if the transformer feeding the house/neighborhood is big enough for the tankless heater.

If everything checks out there, you should have somebody check the panel connections. These will always be hot so I do not recommend doing it DIY. Also have them inspect the outside service drop/meter to make sure that is properly sized for 150 amp service.

If all that checks out the easiest fix is to either replace the tankless with a traditional water heater, or a hybrid like I mentioned earlier. Or have somebody run a hot shower, make some dinner on the stove, run the A/C, and dry a load of clothes and see how long until the main breaker trips. When it does, you can then complain to the landlord that the main breaker is tripping and you need to lighten the electrical load, or increase the size of the service.
 
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Old 07-11-14, 04:48 AM
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OK so the landlord is trying to find every way around this he wants to try and move the breakers around is this an option. I would assume not seeing as everyone on here has already said the box is overloaded he is just addressing the light flicker issue and not the power consumption issue it seems.
It seems to me that the landlord should probably have at least a discussion with whoever sold him the tankless heater installation. Load calcs should have been performed before the tankless unit was ever installed, but I somehow doubt they were. When considering a tankless water heater, the first red flag anyone qualified should see is the house only has a 150 amp service.
 
  #27  
Old 07-19-14, 11:49 AM
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I want to thank everyone for all the help once again I finally got a standard 40 gal tank hot water heater and everything is so much better.

Once again thanks so much for all the replays and all the help.

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  #28  
Old 07-19-14, 12:05 PM
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Thanks for letting us know the outcome.
 
  #29  
Old 07-19-14, 01:15 PM
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I finally got a standard 40 gal tank hot water heater and everything is so much better.
Just so you know, the tank type water heater should have a disconnect. It doesn't look like there is one there, but it could be hidden by the tank. Is there a disconnect?
 
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