Household AC Circuit Loads

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Old 01-26-19, 01:35 PM
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Household AC Circuit Loads

We have a circuit that includes our kitchen with its 220 devices and 110 outlets plus 110 outlets in our living room. This circuit overloads and trips the breaker too frequently. I'd like to investigate balancing the circuit so that amperage draws are lowered but I don't know how to go about it. I can locate and identify the outlets and the range with oven and microwave oven and the switched dishwasher and lighting but I don't know how to determine the optimum amperage load to prevent tripping breakers. We have other circuits that provide power to outlets and lighting in bedrooms that I suspect draw fewer amps. I was wondering if it might be possible/practical to do a bit of rewiring and balance the load better.

Any advice and cautions would be appreciated.
 
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Old 01-27-19, 06:09 AM
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First off you can't have "a circuit" (meaning one circuit) that is used for 120V receptacles plus 120/240V range. You need to investigate a little bit more as to what are on these circuits etc. Map the electrical circuits in the house out. Make note on paper, rough drawing of your home. Placement of receptacles, lights appliances etc and start by turning off one breaker at a time and see what does not have power anymore. Make note on the paper what breaker controls what.

Next is for us to know how large of an electrical service you have at this time. 100 or 200amp service. Also let us know how many available spots you have for new breakers.

This information will be useful as the appliances in the kitchen will draw far more power than most anything else in the home (other than a hot water heater if electric, dryer if 120/240V etc). Running dedicated circuits for microwaves, dishwashers etc will minimize tripping due to overloads.
 
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Old 01-27-19, 12:10 PM
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Thanks for the reply AFJES. Yes, I'm aware that each circuit has it own voltage - that 110/120 and 220/240 are separate circuits with separate breakers. I will have to take the cover off, I think, to determine the amperage of the panel. I would be very much surprised if it is more than 100Amp service.

I am drawing a layout of the panel that I will post later. There are spaces for 20 single breakers. Twelve (12) of the panel slots are used for 6 220/240VAC breakers. Two (2) spaces (19 and 20) are unused and still have the metal tab covers. There is one 110/120 VAC GFCI breaker taking one slot, another single 110/120 VAC slot occupied by a single breaker, and 4 110/120 VAC slots with double breakers.

It will take me a bit longer to diagram all the service points inside the house and to identify which is controlled by which breaker position. Because I have 4 double breakers, should I identify those circuits by number and letter designation (eg, 11A, 11B)? I will try to estimate the amperage load on each circuit and total it to see if the draw overloads the capacity of the whole panel. If not, I might be able to use the vacant slots (19 and 20) to rearrange the load on existing circuits by adding 2 new ones.

Again, thanks for the response and the advice.
 
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Old 01-27-19, 02:49 PM
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Which circuit(s) are tripping? Is it one circuit, multiple circuits or the main breaker?
 
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Old 01-27-19, 04:10 PM
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No need to open the panel to see the ampacity. It should be on the main breakers handle. With 20 spaces available it is most likely a 100 amp panel.

You simply need to add more circuits or use less on the circuits at the same.time. The kitchen circuits should not be shared with bedrooms.
 
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Old 01-28-19, 05:42 AM
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And to help you understand a bit better correct your terminology a little so when you do research on the Internet or read responses you have a better understanding of what you are reading. This is just a helpful hint not criticism at all.

A normal receptacle or lighting circuit will be a single pole breaker (other than on a MWBC) at 120V, not 110/120V. The 110V is older terminology and will only confuse you more. So just refer to it as a 120V circuit.

220/240V is the same thing. Older terminology. It is 240V. Such as if you have an electric hot water heater strictly running only on 240V. An electric dryer or electric stove/range will use 120/240V. The dryer and stove use both 120 and 240 simply for the fact the 120V usually powers the lights, timers, tumbler etc on the dryer and stove/range and the 240V will power the heating elements in the dryer and the stove/range top units and oven elements.

Again, no criticism, just a better understanding of what you are reading and how to interpret it.
 
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Old 01-28-19, 06:29 AM
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... one circuit, multiple ...
What breaker trips?

1. A "submaster" breaker that cuts off the range and the microwave and several lights and the dishwasher and the cake mixer on the counter and the TV in the next room? (There are individual breakers in a small panel for one item each or a few of the items each, that did not trip but everything controlled by that small panel went dead.)

2. One of the small breakers in the "main" panel that cuts off just one or a few small or medium appliances and perhaps some lights for example the ceiling light and the cake mixer and the dishwasher only?

(3. The master breaker cutting off everything in the house?)

If you do not already have two 20 amp circuits serving just receptacles in the kitche and possibly in the dining room or pantry, you could install one or both of these with brand new receptacle locations including several along the counters, and leaving everything else as-is. Bringing the house up to current code requires this.

Changing over existing receptacles onto new circuits can be tricky because the old wires have to remain inside the boxes and there might not be enough space for the new wires.

It is suggested that a circuit that has permanently wired appliance(s) or device(s) that (together) normally use more than half of the circuit amperage not also have receptacles for other things.
 

Last edited by AllanJ; 01-28-19 at 07:06 AM.
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Old 01-28-19, 09:12 AM
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Great information! Thank you each and every one!

As AFJES has figured out, I'm a geezer - past 75 yo but still kickin' jus' not as high. I'll revise my notation and drop the 110 and 220 designations. Thank you.

I'm still in the process of learning about my breaker panel. It is almost certainly a 100 amp panel. I'll have to inspect the main breaker again to find the amperage rating on it.

I still have questions that, if answered, I didn't understand.
1) I can see that the dryer and range would have both 120 and 240 volt service, but there is only one plug for them that I can find. Does that mean that the wiring carries both voltages? If so, how is the 120 VAC provided to the appliances? Are there circuits in the devices that separate the service?
2) How should I go about calculating load? I've read that in doing so one should assume that not all service points will be in use simultaneously; therefore, one doesn't necessarily add all possible loads to determine amperage. Also, some loads are maxed at 15 amps while others are 20 amps and they are not mixed on the same circuit because breakers have amperage ratings and there is only 1 breaker per circuit. So, which types of circuits should be 20 amp service and which 15 amp?
3) I suppose that using the double breakers saves on the number of physical breakers installed on the service bar allowing more circuits to be served by the box. I'll have to check, but I think each is rated for either 15 or 20 amps per circuit, ie, they are not mixed 15 and 20 amp service circuits on the same double breaker. My question is whether or now this might contribute to overloading the panel, especially if I were to add a couple more circuits to the panel using the empty 19 and 20 positions?

Thanks again for all your input. I'm not going to do anything or even make any decisions about change without thoroughly vetting the situation and getting proper advice and then hiring an electrician.
 
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Old 01-28-19, 10:31 AM
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1) you get 240 volts when you use the two hot wires. When you go from either of the two hots to the neutral wire you get 120 volts. So the dryer and the stove both have the two hots AND the neutral wire. Thus anything internal to the device that needs 120 just uses one of the hots and the neutral. The stuff that needs 240 volts (heating elements) uses only the two hots.

2) A breaker does not use any power. It just limits the amount of power that flows through the wires. Looking at the breaker is no good for figuring your load. You need to look at the wattage or current ratings of the devices on each circuit.
 
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Old 01-28-19, 04:16 PM
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RabbitHutch: Clarification needed please from you. You mention your range and dryer BUT what we have not yet determined is whether these two appliances are electric (strictly) or gas/electric.

#1 - is your stove a gas stove but plugged into a receptacle?
#2 - is your dryer a gas dryer but plugged into a receptacle?
Although the two above appliances may run on gas they still need electric to operate. However the electrical circuits are much different than if these two appliances were electric only.

I still have questions that, if answered, I didn't understand.
1) I can see that the dryer and range would have both 120 and 240 volt service, but there is only one plug for them that I can find. Does that mean that the wiring carries both voltages? If so, how is the 120 VAC provided to the appliances? Are there circuits in the devices that separate the service?
As "joed" mentioned a receptacle can carry both 120v and 240V depending on the appliances needs and how the receptacle is wired, the type of receptacle and the breaker needed to carry the load. First questions to answer are my above.

2) How should I go about calculating load? I've read that in doing so one should assume that not all service points will be in use simultaneously; therefore, one doesn't necessarily add all possible loads to determine amperage.
This is absolutely correct and the biggest mistake that most homeowners make. The proper way for a homeowner to determine what their panel is, is to look at the main breaker. On the tip of the handle of the breaker should be imprinted the number which designates the amperage rating of the main breaker.

So, which types of circuits should be 20 amp service and which 15 amp?
This depends on the need requirements of the circuit and of course what the NEC code dictates.

I suppose that using the double breakers saves on the number of physical breakers installed on the service bar allowing more circuits to be served by the box.
This statement is not quite correct. Double pole breakers are used for
120/240V circuits
240V circuits
MultiWire Branch circuits.
They are not used to save space.
A tandem or piggy-back breaker (there are more names of these type breakers used in the field) is used to save space however not all panels are rated to use these types of breakers. But let us not get involved in this at this point until we know more information

A picture of your breaker panel would help. NO NEED to take the cover off the panel. Just open the door of the panel and take a clear picture so we can see all the breakers and hopefully the brand name of the panel. Let us know what the main breaker says (what number is imprinted on it).

Also, is this breaker panel the only panel in your home?
 
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Old 02-04-19, 10:16 AM
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Sorry to have taken so long to reply.

First, we have no natural gas service. All power is provided by electricity from the main service, no augmentation from solar, wind, whatever.

Sorry for the lousy pic of the panel and its orientation. The pic was not sideways until I uploaded it here. It is a 100 amp service panel with 20 positions on the buss. There are 6 240 VAC 30 amp breakers at buss positions 1- 3, 2- 4, 5-7, 10-12, and 15-17. There is 1 120 VAC 20 amp breaker at position 9. There is 1 120 VAC GFCI breaker at position 14. There are 4 120 VAC 20 amp piggy back breakers serving 8 circuits at positions 11, 13, 16 and 18. There are 2 unused positions on the buss at the bottom of the panel, positions 19 and 20.

I have not yet mapped the service outlets back to the breakers. This going to involve moving furniture and other heavy lifting. I'm waiting for a visit from my SIL.

Is there an inexpensive device that can be plugged into the 120 receptacles that will generate a tone to be picked up by a probe? I've seen some on Amazon and eBay that seem to be a bit expensive for 1-time use. Is there another, less costly solution?

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Old 02-04-19, 03:40 PM
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Easiest way I have found to map 120 circuits is plug in a radio and then trip breakers until it stops. You can then use an outlet tester to see what else has gone dead on that circuit.
 
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Old 02-04-19, 05:10 PM
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That 100A Square D QO panel is screaming. Those are not all 2P30A breakers. Some look like 50's. Possibly a 40A. Look closely at the handle.

You've got an electric stove, electric heating, electric hot water.
 
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