Question about Electrical Supplies

1 Answer

My main breaker panel feeding our entire house built 1996 is rated at 150A. Yet if I add up all the breakers inside, they total 600 amps !!! Is this a safety issue? Is it up to code?

Since the house was built, the previous owner likely added circuits to finish the basement fluorescent lights in the drop ceiling and wall outlets, but the vast majority were likely there at original house build.

Posted by on


1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert that has over 500 points.

  • Expert
  • 240 Answers

No problem. You would never have a situation where every circuit in the panel was loaded to its max. The panel size itself limits the number of breakers, and total number of circuits. The 150 A breaker protects the box itself against too much load on the buses in the back that the breakers connect to. No worries about this.

Posted on Jun 03, 2017


6 Suggested Answers

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

  • 50 Answers

SOURCE: how to determine electrical power panel load capacity

The total panel ampacity should be rated first by your load, then by the main breaker. if you are feeding it out of another box, it will probably be a double 100amp. In that case you will probably use 100amp SER cable.

Posted on Apr 10, 2009

  • 1714 Answers

SOURCE: 15 AMP versus 20 AMP outlet plug

The circuit is protected by the 15 amp breaker. That's what matters, the wire size and the breaker feeding it. It's OK to have a 20 amp recepticle fed by a 15 amp breaker.

Posted on Sep 11, 2009

Testimonial: "Concise answer"

  • 143 Answers

SOURCE: arc circuit breaker won't reset


Posted on Sep 20, 2009

Testimonial: "thank you for the advice it worked and everything is working. "

  • 8404 Answers

SOURCE: Lights & outlets in addition, how many on 20 amp breaker?

I would say something a little different than SmithBrother. You said you are putting on an addition and you asked how many outlets can you put on a 20 amp breaker. Because of the date on your comment, it is probably a little late to be replying but whaat the heck ... here goes.

I think there is a rule of thumb that you can put about 12 "holes" in a 15 or 20 amp circuit. A "hole" is a hole in the wall where a box would be put for a outlet or a light or a switch. I presume you know to use #12 wire on a 20 amp circuit and while you may use #14 on a 15 amp circuit, I prefer to shy away from #14 wire even though I MAY protect a given circuit with a 15 amp breaker. You can over protect but not under protect. 30 amp is #10 and so forth.

There are lots of other considerations ... too many to do justice in this short comment. However, I will hit a few hi lites. As SmithBrother says, a micro wave should have its own circuit as should a AC or a frig - I think that may go without sayng. I think you are speaking more general use. I believe the electric code says every wall must have a plug in it and you can go no more than 6 feet to get to a plug. So, if you have a 12 foot wall, one outlet in the middle will meet the requirement. There is nothting preventing you from puttine two outlets in that same wall. From my perspective, I want to have lots of outlets and I want them to be convenient for me to use. (There are more than 200 outlets in my home) Another thing, you cant put a outlete over a electric baseboard heater. You can put one at each end of such a heater but not where a lamp cord would lay in top of the hot heater surface.

Regarding the 12 hole rule ... if you have two switches that control the same light, you only count those two switches as one hole even though, obviously, there are two holes in the wall for the two switches. Count a second hole for the light. Conversely, if there is a light and a fan, you should count that one hole in the ceiling as two.

Posted on Oct 07, 2009

  • 99 Answers

SOURCE: I have an ITE breaker panel (G2020MB1100) with

Yes they will fit. They are both a single pole breaker. Turn the breakers over. They should look the same and snap into a single slot in the panel the same.

Not sure what you mean by No Clip? A Square D QO Breaker has a metal clip that snaps into the panel on the breaker mount and one on the Bus Bar.

Posted on Feb 22, 2011

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

5000 watt inverter schematics circuit

If you have (90) 50w lamps = 4500 watts total. Assuming a 120/240 panel, if you put 1/2 on one "side" of the panel and the other 1/2 on the other "side" of the panel, that would be 2250 watts on each half. The generator should be rated *at least* 125% of the load; 4500w x 1.25 = 5625W. Using a 4500W generator on this load will cause it to overheat and shorten its life as it is running at 100% of capacity all the time..

One half of the panel is 120V to neutral, and the other is 120V to neutral - or 240V between both circuit breaker terminals. Ohms law for DC circuits and purely resistive AC circuits says Volts x Amps = Watts; or Watts / Volts = Amps. So, 2250W / 120V = 18.75A on each pole of a 2 pole circuit breaker that feeds the sub panel. A #12 copper wire is rated for 20 amps; but as per National Electrical Code - must be de-rated to 80% of rating which means it is good up to 16 amps maximum. A #10 copper wire is rated for 30 amps, but it too must be derated to 80%, making it good for 24 amps maximum. So, if you are going to feed a sub panel supplying (90) 50watt lamps, you will need to run a #10/3 copper cable from a two pole 30 amp circuit breaker at the generator to a 120/240 volt "main lug only" sub panel rated for at least 30 amps.

Divide your load evenly across the sub panel - (4) 15 amps circuits via (2) two pole 15 amp circuit breakers on each "side" of the panel if you run (2) 14/3 cables out to the lights - or (4) single pole 15 amp circuit breakers if you run (4) 14/2 cables out to the lights. No circuit breaker terminal should have more than 23 lamps that means you have (2) w/ 22 lamps and (2) with 23 lamps. The circuit w/ 23 lamps will draw 23 lamps x 50w = 1150W. 1150W / 120V = 9.6A. The 22 lamp load will be 22 x 50w = 1100W. 110W / 120V = 9.2A. Which is well within the 12A maximum allowed (after derating as required by code) by a #14 copper wire rated for 15A.

Good luck!

Mar 10, 2014 | Electrical Supplies

1 Answer

I purchased a 7000W Westinghouse Portable Generator to back feed my circuit breaker box. The cable is rated to 30amps. Do I use a 30 amp or a 40 amp circuit breaker? Thanks, Mike

1) Match wire and breaker:

2) 7000 watts divided by 240 volts = 29.1 amps.
30 amp breaker x 80% safe maximum = 24 amps.
This means you should use 8 gauge wire and 40 amp double pole breaker for 240volt

3) 7000 watts divided by 120 volt = 58.3 amps.
60 amp breaker x 80% safe maximum = 48 amps.
So use 70 amp breaker and #4 wire.

Jan 30, 2013 | Electrical Supplies

1 Answer

Do i need a main breaker for a 200 amp panal?

This looks like an indoor panel. If you have an outdoor panel next to (or below) the power companies meter, It should have the breaker to feed such a panel. Thus, this indoor panel should only be required to have "main lugs" to receive wire from outside breaker. NEVER size breaker outside bigger than the equipment rating of inside devices. If from the power companies meter you intend to feed this panel, YES it is required to have a Main Breaker.

Apr 02, 2012 | Square D Qo 200 Amp 40 Circuit Indoor...

1 Answer

I have a 125 FPE box currently the combined total of all breakers presently in the box is 190 amps. I am wanting to replace a single pole 20 with a single pole 40. Am I already maxed out or do I have room...

You can add the breaker.
The key is total electric use.
As long as total consumption does not exceed amps shown on main breaker, then the new 40A breaker installation is ok.
If total consumption exceeds main breaker, then the main breaker will start to get hot and then trip.

Put hand on main breaker and feel for warmth.
The main should not feel warm.
Consider upgrading to 150A or 200A service.

Aug 22, 2011 | Connecticut Electric UBIF040N FPE...

1 Answer

Electrolux EOB 6632 oven trips main house circuit breaker if used above 180c. Installation electrician has done whole house test, says everything normal, must just be a particularly sensitive ciecuit...

Hi, welcome to FixYa! my name is Shaun. I hope i can help you out with your question. Your main house breaker is tripping over 180C because of the amount of current your oven is drawing. Keep in mind that an oven is capable of pulling up to 1/4 the amount of amperage of your total house current capacity, up to 50 Amps. This is assuming you have a typical 200 Amp main breaker. Add this in with your heating/air-conditioning, up to 30A, if electric, your water heater, 25 A if electric, and whatever lights and appliances you have plugged in and turned on, you can imagine how quickly those amps add up when your oven is on. Your oven breaker won't trip because you're not exceeding 50A on that circuit, however if your total household load is exceeding 200A, your main will trip. Also, breakers lose efficiency over time. Sometimes they can drop current capacity by as much as 25%. So your best bet is to replace your house main and see if that fixes your problem. Hope this helps out. Have a good day!

May 05, 2011 | Electrolux EOB6632 Electric Single Oven

1 Answer

1 question can Cutler Hammer breakers have the amperage feed through the breakers. To the breaker box and from the box grid to the load. Does it matter which way the amperage is fed through the breaker?...

There seem to be several questions mingled in with those 2 questions.

1) Amps can go either way

2) Breakers trip when heat exceeds certain level. Heat is caused by amps.

3) You want to add a subpanel in garage.
I do not know the code in your area for installing a subpanel.
Your plan will work by connecting 6 gauge wire to main breaker, and new 60 amp breaker will protect wires between main box and subpanel.
Remember, wires going into main breaker cannot be turned off without pulling meter.
Some areas require license to pull meter.

4) To work around license and meter-pull, simply replace a 240V breaker in main panel with your new 60 amp breaker.
Then move breakers around to match new set-up.
New subpanel can accommodate two new 240V breakers and one new 120 Breaker

5) 6 gauge wire is correct for 60 amp breaker.

6) I'm not sure what you mean by the box rails?

7) Do you need more amperage on main service?
This means adding a larger service panel with 150 Watt or 200 Watt main breaker.
Some areas require service upgrade when remodeling or adding circuits.

8) How to figure total amp draw at your house.
Add up total watts being used.
For example you have 1/2 Hp motor
754 watts per Hp
1/2 Hp = 377Watts
Volts x Amps = Watts
Amps = Watts divided by Volts.
377 Watts divided by 240Volts = 1.57 amps (plus a bit more amperage when motor starts)
40 watt light bulb divided by 120Volts = .33 amps
Double oven has label located inside door that shows upper and lower wattage.
Dishwasher, dryer, big screen TV, satellite receiver all have labels that show wattage.
Water heater has label that shows wattage of each element.

Add a comment for more help

Feb 18, 2011 | Cutler Hammer 100 Amp Main Breaker...

1 Answer

I have a Rheem Model # 82V52-2 and its being supplied by 25 amp breakers. They do not trip out but the 100 amp main gets real hot and trips out and I believe it happens when the water heater is in use- any...

The Rheem water heater uses 4500 Watt elements
Check label on side of any appliance to see electrical rating details
2 element tank with two 4500 watt elements is still a 4500 watt appliance since both elements are never ON at same time.

Volts x amps = watts
amps = watts divided by volts

amps = 4500 divided by 240Volts or 220Volts
amps = 18.75
Your water heater uses 18.75 amps to 20.45 amps

Your 25 amp breaker should only carry 80% of rated value
25 amps x 80% = 20 amps.

So your water heater breaker is correctly sized.
You should have a 10 gauge wire going to this water heater.
12 gauge wire is a bit undersized for 4500 Watt water heater
Feel the water heater wire to see if it is warm.

If the main breaker is getting hot when 20 additional amps are being used by the water heater.
1) The house is using more amps than your 100 amp main can carry
Using the formula, 100 amps x 80% = 80 amps for the main breaker
Add up your total amp draw.
For example if your 3500 watt oven is ON, it draws 16 amps.
If your 5000 Watt electric heater is on, it draws 23 amps.
Your 1500 Watt 120V microwave draws 12.5 amps.
Add these numbers up plus your water heater, and it comes to 71 amps.
71 amps is getting close to the max 80 amp, but it's not over.
Now if you have a pool pump and and hot tub and a table saw going, the main breaker could be overdrawn.

2) To solve the problem short-term, you can put a timer on the water heater and use it only when needed.

3) The main breaker is bad and needs to be replaced.

If you need help figuring circuits or timers, add a comment and I will help

Nov 05, 2010 | Rheem Water Heaters

1 Answer

Main breaker is kicking out

Please call an electrician. There are 3 possibilities---- 1. The sum of the branches are occasionally spiking higher than 200 amps. (If you add up all of the branch ratings you will find that their combined capacity is much higher than 200 Amps in total) In this case you need to find a way to level the load or add capacity by adding a second breaker box -- you can't do this yourself because you need help from the utility company. 2. There is something shorting out inside your breaker box. (unlikely) 3. There is a problem with the main and you need to replace it. But DO NOT ATTEMPT TO DO THIS YOURSELF. In all three cases you need help from an electrician.

Jun 18, 2010 | Cutler Hammer Eaton Electical #BD3030...

1 Answer

How to determine electrical power panel load capacity

The total panel ampacity should be rated first by your load, then by the main breaker. if you are feeding it out of another box, it will probably be a double 100amp. In that case you will probably use 100amp SER cable.

Mar 30, 2009 | Thomas & Betts Electrical Supplies

2 Answers

Electrical - Air Conditioning

Ben, you are on the right track. To upgrade the breaker, first look at the main house breaker panel and determine if allowing more current through main breaker will be taxing it too highly (will 20 more amps exceed my main breaker limit...what is the main breaker current trip at?) Then look at the wire size leading away from the 40 amp breaker to outside. If it is 6 gage copper or 4 gage copper-clad aluminum wire, you are ok to upgrade. Any smaller wire size could be unhealthy.

Sep 03, 2007 | Heating & Cooling

Not finding what you are looking for?
Electrical Supplies Logo

Related Topics:

446 people viewed this question

Ask a Question

Usually answered in minutes!

Top Electrical Supplies Experts

ken skalski

Level 2 Expert

152 Answers

Gene Haynes

Level 3 Expert

5245 Answers

Brad Brown

Level 3 Expert

16174 Answers

Are you an Electrical Supply Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides