# Thread: Determining the amperage mat a main disconnect fuse block

1. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Vern Heiler
There diagram will work just fine! Just needs a little help.....

Grounded or ungrounded it doesn't matter --answer still the same. If these two transformers were wound as drawn there is no difference between them. You need to understand basic transformer theory. Since Jim and Robert don't, how can they understand the circuit and math? Smoke (lots of smoke) with a trace of bad math and mirrors = wrong answer.. If what you say is so then you could prove it in the lab. and you would find that one was a +60 amps and the other (at the same instant) would be a -60 amps. Besides circuit #1 is not the circuit we are talking about. Just more confusion from a couple of politicians that are weak in math..

2. ## Re: Determining the amperage mat a main disconnect fuse block

Circuit 1 is exactly the situation that was described when the capacity of the panel was described at 120 volts. It was also stated that the capacity was 60 amps at 240 volts.

Stop deflecting and answer the questions. This has never been about transformers.

3. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Roland Miller

Grounded or ungrounded it doesn't matter --answer still the same. If these two transformers were wound as drawn there is no difference between them. You need to understand basic transformer theory. Since Jim and Robert don't, how can they understand the circuit and math? Smoke (lots of smoke) with a trace of bad math and mirrors = wrong answer.. If what you say is so then you could prove it in the lab. and you would find that one was a +60 amps and the other (at the same instant) would be a -60 amps. Besides circuit #1 is not the circuit we are talking about. Just more confusion from a couple of politicians that are weak in math..
I understand what you are saying Roland but + and - amps might just be a bit of a misnomer. Current flows in a direction due to + and - potentials. What is important is that if you push one electron in one end of a wire you only get one out the other end of the wire, not two.

4. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Vern Heiler
I understand what you are saying Roland but + and - amps might just be a bit of a misnomer. Current flows in a direction due to + and - potentials. What is important is that if you push one electron in one end of a wire you only get one out the other end of the wire, not two.
It is all about which way the electrons are flowing at any instant in an AC circuit. DC is a little more straight forward.

Sorry Jim and Robert you are using oranges to prove an apple theory and you have failed at a very basic level.. 5th grade math. Catch you on the next one if you don't overload in theory

5. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Roland Miller

Sorry Jim and Robert you are using oranges to prove an apple theory and you have failed at a very basic level.. 5th grade math. Catch you on the next one if you don't overload in theory
So you are leaving this discussion without proving anything except that you do not understand a simple 120 circuit? If you were so sure of yourself why did you not ask electricians on one of their forums?

6. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
So you are leaving this discussion without proving anything except that you do not understand a simple 120 circuit? If you were so sure of yourself why did you not ask electricians on one of their forums?

Apparently you think the tail should wag the dog. I have nothing to prove. The math and science of electricity is all that is needed to prove my position.. I have posted enough information that anyone of average intelligence can work through it and come to the same conclusion I have posted. They couldn't do the same for your position. So you can continue you struggles with the math and science of electricity alone....some nuts are too tough to crack

7. ## Re: Determining the amperage mat a main disconnect fuse block

It is just a shame the wrong conclusion would be reached. Vern even drew the diagram showing the 2 legs carrying 60 amps at 120 volts and some still don't see it.

Why will you not answer Robert's question? How hard is it to add 20 + 20?

8. ## Re: Determining the amperage mat a main disconnect fuse block

It is just a shame that homeowners will have to pay to have erroneous information like this refuted simply because of a lack of understanding of the subject matter on the part of the inspector.

9. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
It is just a shame the wrong conclusion would be reached. Vern even drew the diagram showing the 2 legs carrying 60 amps at 120 volts and some still don't see it.

Why will you not answer Robert's question? How hard is it to add 20 + 20?
Jim, I was wanting to just let this go until you tried to put words in my mouth. You really are a spin master. Vern might have shown that each leg has 60 amps, but Vern also said they are the SAME 60 amps.

10. ## Re: Determining the amperage mat a main disconnect fuse block

Diagram 1 shows 2 independent 120 circuits. They cannot be the same 60 amps being measured. Just because the values are the same does not mean they are the same amps. Vern is wrong about that.

11. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Robert Meier
Still no takers on the simple question in post #122.
Oh hell ya!

It's 40 amps on the same leg, and if you were to add a 10 amp load on the other leg it would still be 40 amps. If you were to look at the series of diagrams I posted (Fig 1 through Fig 5), and were to be able to comprehend, you would see how this is. Please feel free to make the arrows double ended (pointing both directions) to satisfy your distaste for a single point in time (DC representation). And yes I do know that I left out a load by mistake and drew an extra wire that would cause a short, but if you can't fix that you should not get anywhere near electricity!

12. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Robert Meier
So you're saying if I install a third circuit breaker on the other leg with a 10 amp load the total 120 volt connected load is still 40 amps?
You are still mixing AMPS AND POWER. We are talking AMPS and have been since the time it was stated that you could have 120 amps on a 3-wire 60 amp circuit. Ten of the same 40 amps that is on the first leg now goes through the second leg. The other 30 amps still returns through the neutral. Again if you want to talk amps, lets talk amps. If you want to talk power, lets talk power.

13. ## Re: Determining the amperage mat a main disconnect fuse block

No, you would have a panel with a 50 amp load, 40 on one leg plus 10 on other other. The neutral load would be 30 amps. The current is not crossing to the other hot as they are 120 volt and the return is on the grounded conductor, not the other hot leg.

14. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
No, you would have a panel with a 50 amp load, 40 on one leg plus 10 on other other. The neutral load would be 30 amps. The current is not crossing to the other hot as they are 120 volt and the return is on the grounded conductor, not the other hot leg.
First give a definition of "amp load".

Second tell us how the current got there.

If you don't get this right, I'm joining Roland on the side-line. I mean after all most people don't really need to have a picture drawn for them, its just an expression!

15. ## Re: Determining the amperage mat a main disconnect fuse block

Do you really need someone to tell you that running equipment from a panel places a load on it? Amps are a measure of the load. A demand load calculation for a service gives you the expected load in amps.

The current got there by the equipment being used. If it were turned off there would be no load.

Go ahead and sit out. Robert and myself are sure of our answers and have given numerous examples to prove ourselves correct.

16. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
Do you really need someone to tell you that running equipment from a panel places a load on it? Amps are a measure of the load. A demand load calculation for a service gives you the expected load in amps.

The current got there by the equipment being used. If it were turned off there would be no load.

Go ahead and sit out. Robert and myself are sure of our answers and have given numerous examples to prove ourselves correct.
A load is work being performed, work requires power...do you see where this is going?

The current got there by the equipment being used!!!! Roland... slide over and hand me a beer, I'm done!

17. ## Re: Determining the amperage mat a main disconnect fuse block

The math and science of electricity is all that is needed to prove my position.. I have posted enough information that anyone of average intelligence can work through it and come to the same conclusion I have posted. They couldn't do the same for your position. So you can continue you struggles with the math and science of electricity alone.

Electricity is exactly predictable with math. Once the math is done you could build the circuit in a lab and measures every value (and verify) you calculated. You couldn't do that with your fuzzy math problem..

18. ## Re: Determining the amperage mat a main disconnect fuse block

What the circuit will support is right on the breaker handle or fuse label. Why you and Vern will not believe this is beyond me.

I see that you are still not sure enough of your position to ask the same question on and electrical foruma and post a link here so others can see the correct answer.

You said the math is easy to prove and it is. Watch this: 60 amps x 120 volts = 7200 watts, 7200 x 2 for the number of legs in the panel = 14400 watts.

60 amps x 240 volts = 14400 watts.

Look they match.

Last edited by Jim Port; 08-09-2013 at 09:33 AM.

19. ## Re: Determining the amperage mat a main disconnect fuse block

There is not a single point in either circuit that will see more than 60 amps. In fact the second circuit would work without the grounded (center) conductor..

- - - Updated - - -

Originally Posted by Jim Port
What the circuit will support is right on the breaker handle or fuse label. Why you and Vern will not believe this is beyond me.

I see that you are still not sure enough of your position to ask the same question on and electrical foruma and post a link here so others can see the correct answer.

You said the math is easy to prove and it is. Watch this: 60 amps x 120 volts = 7200 watts, 7200 x 2 for the number of legs in the panel = 14400 watts.

60 amps x 240 volts = 14400 watts.

Look they match.
Here's the correct math

math.JPG

You are still mixing apples and oranges. you are taking a 240 volt calculation and using 120 volts to prove you point.

- - - Updated - - -

I don't need to check with anyone.. I just use math and science. You use smoke and mirrors..

20. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
What the circuit will support is right on the breaker handle or fuse label. Why you and Vern will not believe this is beyond me.

I see you have shifted your position again. So you agree that a 2 pole-60 amp CB or 2 60 fuses will only support 60 amps now. Amazing. Never the 120 amps you have been spouting about...This is more than funny..

21. ## Re: Determining the amperage mat a main disconnect fuse block

My position has NEVER changed. I have said since the beginning of this thread that the panel in question can support 120 amps at 120 volts or 60 amps at 240 volt. Go back and check.

Again you confused how many legs in the panel there are. Myself and several others have tried to point out your confusion and math errors. I see that you are going to continue to twist this however you want instead of admitting your blindness.

Good Day.

22. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
My position has NEVER changed. I have said since the beginning of this thread that the panel in question can support 120 amps at 120 volts or 60 amps at 240 volt. Go back and check.

Again you confused how many legs in the panel there are. Myself and several others have tried to point out your confusion and math errors. I see that you are going to continue to twist this however you want instead of admitting your blindness.

Good Day.
Thanks for saying you agreed with me from the very beginning. If you would drop the 120 amp thing you would get a passing grade. I am sorry I am still laughing... oh you have tried to confuse amps and watts, 240 volt calculations with 120 volt calculations and you are still loosing. Do you still have that roofers card? I hear it covers everything and what you are sitting on badly needs covered.

Math teaches a life skill called adaptive reasoning. Something you apparently don't have.

23. ## Re: Determining the amperage mat a main disconnect fuse block

I do not agree with you, you simply do not understand that there are TWO INDEPEDENT legs in the panel, EACH capable of allowing 60 amps to flow. Even if you were to remove one fuse you could still pull 60 amps from the other leg. The two 120 volt legs are the key to understanding this, not some extraneous number.

BTW, every time you post Diagram 1, you reinforce my position.

24. ## Re: Determining the amperage mat a main disconnect fuse block

Thanks for dropping the 120 amp stuff(you couldn't prove it anyway) and agreeing with me again. You are up to a D-, barely.

You don't seem to understand what this discussion has been all about--120/240 volt, single phase service with a 2-pole 60 amp breaker (close to diagram #2). Or do you even know what three elements are required to make up a circuit?

I know I should have stopped when my BS meter needle pegged and was bent, but when you accused me (and Vern) of costing some poor home owner money because we were spreading mis-information, I guess you raised my hackles. When in fact you and Robert are the ones doing this. What office are you guys running for? Are you Jerry's and HG's apprentices?

My suggestion for you two is to stick to topics you have some correct knowledge of and leave the rest to someone else.

Read my signature--and live it. You won't run into so many rocks

25. ## Re: Determining the amperage mat a main disconnect fuse block

Since you seem to like oranges. Suppose you have an orange juice factory with one machine that can produce 10 gallons of OJ per hour. You have plenty of extra oranges and enough floor space to add a second identical machine. How many gallons of OJ can you produce using both machines for one hour? I bet your answer is 10 gallons.

26. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
Since you seem to like oranges. Suppose you have an orange juice factory with one machine that can produce 10 gallons of OJ per hour. You have plenty of extra oranges and enough floor space to add a second identical machine. How many gallons of OJ can you produce using both machines for one hour? I bet your answer is 10 gallons.

“You are not entitled to your opinion. You are entitled to your informed opinion. No one is entitled to be ignorant.”
Harlan Ellison

You seem to take entitlement very seriously

27. ## Re: Determining the amperage mat a main disconnect fuse block

No, I feel that the truth and facts need to be told. I am kind of like the kid that told the emporer that he wasn't wearing any clothes. The truth doesn't change.

Thank you for this thread. I will use it as an example of what happens during so many home inpsection reports and why the "defects and issues" are so easy to refute. Thankfully all HI's are not so lacking.

BTW, the question posted in #122 remains unanswered. Quite a stumper wasn't it?

28. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
No, I feel that the truth and facts need to be told. I am kind of like the kid that told the emporer that he wasn't wearing any clothes. The truth doesn't change.

Thank you for this thread. I will use it as an example of what happens during so many home inpsection reports and why the "defects and issues" are so easy to refute. Thankfully all HI's are not so lacking.

BTW, the question posted in #122 remains unanswered. Quite a stumper wasn't it?
You are more then welcome. Make sure they get the whole thread to read because anyone with average intelligence and a 5th grade education will figure out you are wrong. Although they will need a Phd in Bull Crap to figure out how you got it so wrong.

- - - Updated - - -

Originally Posted by Robert Meier
Misinformation, definitely Jim nailed it. Actually Jim and I are trying to keep a few of you from embarrassing yourselves any further with more nonsense. Either there's a high level of ignorance coming from a select few in this thread or there are just trolls lurking about. I would vote for the former since even a troll would have quit long ago.
Both you guys are arguing with math and science. Hows it going? I am just pointing out the facts. One of which is --it is you that are doing a disservice by spreading misinformation.

I was once told by a very wise man--It is better to be thought of as a fool then to open one's mouth and remove all doubt like you two have...

29. ## Re: Determining the amperage at a main disconnect fuse block

And once again you ignored a another direct question asked of you. How much OJ can you get from the 2 machines? Can you get twice the water out of the two hoses attached to Hoover Dam as you would with just one?

You are arguing against the math facts as presented. You don't understand them so you think they are wrong despite numerous explanations and analogies to help you understand.

Last edited by Jim Port; 08-09-2013 at 02:34 PM.

30. ## Re: Determining the amperage at a main disconnect fuse block

Originally Posted by Jim Port
And once again you ignored a another direct question asked of you. How much OJ can you get from the 2 machines? Can you get twice the water out of the two hoses attached to Hoover Dam as you would with just one?

You are arguing against the math facts as presented. You don't understand them so you think they are wrong despite numerous explanations and analogies to help you understand.
Jim, take diagram or circuit #1 that you are so proud of and complete each side by connecting a load to each. You do know that no circuit will work unless it is a closed loop, right! Now counting the number of amps. With your method there are 240 amps (ya got to count each leg of each circuit with your method) Wow! now we have 240 amps. If we keep this up we can put Duke Power out of business in no time. Now because we can see this will not work, lets try circuit #2 . Put a load on between the neutral and one of the legs that draws 60 amps. Now all 60 amps obviously is gong through the neutral. That's ok, all is good, but do we have 60 amps or 120 amps? (Oh I do hope you said 60 amps) Now put a load across the other leg to neutral that draws 60 amps. Does any of the current flow through the neutral? No! So where does it go? It goes through the other leg. Should we measure it again? It didn't sound like a good idea for circuit #1 did it? No one has said you could get 240 amps so why would we now say we can get 120 amps?

31. ## Re: Determining the amperage mat a main disconnect fuse block

Keep trying Vern, wrong on both counts. You still have 60 amps on each ungrounded conductor. Each ungrounded conductor in the 120 volt branch circuit is also carrying the 60 amp return current. You do not count this towards the panel capacity. In the 240 example there would be no current on the system neutral if both legs are balanced. Also the current on the neutral has nothing to do with the capacity of the fuse or breaker in this example. The OP asked how much could the 2 pole 60 amp fused pullout supply.

No one has said anything about having 240 amps because you do not. The fuse or breaker would have opened at 60 amps and you do not count system neutral current unless sizing a service or feeder. Your attempts to disprove myself and Robert and the others gets more ridiculous each time.

It is a shame that two independent 120 volt 2 wire circuit has you so confused. Maybe you can answer the question in Post #122? How much current is needed to trip a 20 amp branch circuit?

32. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
What the circuit will support is right on the breaker handle or fuse label. Why you and Vern will not believe this is beyond me.

Look they match.
I guess you have made that pretty clear.

Last edited by Vern Heiler; 08-09-2013 at 05:51 PM. Reason: sp.

33. ## Re: Determining the amperage mat a main disconnect fuse block

Just another comment taken out of context. Let me spell it out for you. I will type slowly.
How two people can ignore how much current a fuse or breaker will allow before opening after numerous and different explanations defies logic. It is clearly labeled. I tried to give you the benefit of the doubt, but I see that was wasted.

Simple questions have been asked like how much current will a 20 amp breaker pass, how much will two pass and the answers, if given, are about the neutral or transformer winding or some other extraneous BS not germane to the original question.

Both your and Roland's attempts to prove the world to be flat again have failed.

34. ## Re: Determining the amperage mat a main disconnect fuse block

You have never answered this from post #9.

I guess you will have to show me where you could measure 120 amps on a 3-wire, 120/240, single phase transformer with the 120 volt phase/circuit each pulling 60 amps???

And don't get confused about the transformer thing. We all know it is way over your heads. This is the circuit under discussion, ie. apples..

In fact there are numerous questions Jim and Robert have failed to answer. They would all show their logic is screwy...

35. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
Do you really need someone to tell you that running equipment from a panel places a load on it? Amps are a measure of the load. A demand load calculation for a service gives you the expected load in amps.

The current got there by the equipment being used. If it were turned off there would be no load.

Go ahead and sit out. Robert and myself are sure of our answers and have given numerous examples to prove ourselves correct.
Kirchhoff's First Rule (Junction Rule) is based on the conservation of charge. It states that:

“At any junction point, the sum of all currents entering the junction must equal the sum of all currents leaving the junction.”

This means that when current reaches the branches in a circuit, it will split up and take different routes. When the branches come back together, the currents will add back together too.

36. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Roland Miller
I guess you will have to show me where you could measure 120 amps on a 3-wire, 120/240, single phase transformer with the 120 volt phase/circuit each pulling 60 amps???
You just answered this yourself. What does each leg pulling 60 amps add up to? A very simple thing you keep ignoring. 60 + 60 = ?????

37. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
You just answered this yourself. What does each leg pulling 60 amps add up to? A very simple thing you keep ignoring. 60 + 60 = ?????
You've done the easy part, now make this work: When the branches come back together, the currents will add back together too.

38. ## Re: Determining the amperage mat a main disconnect fuse block

Again you show your lack of understanding of the topic that has been debated for well over 100 posts. This has NOTHING to do with transformers, combining currents or anything else. Clear your mind of your preconceptions and read what is written. The statement was made by myself and others that the panel could SUPPLY 120 amps at 120 volts. You and your friend do not understand the basis of this statement and I do not think you ever will. You were given a chance to have your theory proven on a professional electrical forum but did not avail yourself of that opportunity, but as Robert said, you did avoid the embarrassment.

39. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
Again you show your lack of understanding of the topic that has been debated for well over 100 posts. This has NOTHING to do with transformers, combining currents or anything else. Clear your mind of your preconceptions and read what is written. The statement was made by myself and others that the panel could SUPPLY 120 amps at 120 volts. You and your friend do not understand the basis of this statement and I do not think you ever will. You were given a chance to have your theory proven on a professional electrical forum but did not avail yourself of that opportunity, but as Robert said, you did avoid the embarrassment.

THis was never the original question. You and Robert introduced this series of unrelated questions (oranges) to prove your ignorant answer. I will keep bringing you back to the original question which you have never answered. 120/240 volt, single phase AC source(can't use transformer cause it scares them) with 2-pole 60 amp breaker with a 60 amps on each phase..

It's simple addition why can't you solve it? Use Kirchhoff's circuit laws. They are simple addition also.

40. ## Re: Determining the amperage mat a main disconnect fuse block

I simply corrected your post where you said,

From Post #5.
Originally Posted by Roland Miller
At 120 volts you still only have 60 amps available.
I then corrected you by saying this in Post #8

Originally Posted by Jim Port
Fixed this for you. At 120 volts you still only have 60 amps available per leg.
From Post #4;

Originally Posted by Robert Meier
Those two guys are incorrect and you're right. The feeder is 60 amp @ 240 volts (or 208). At 120 volts you would have a capacity of 120 amps but that nothing to do with the rating of the feeder.
Since that point you have failed to understand. We have simply corrected your error.

41. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
Again you show your lack of understanding of the topic that has been debated for well over 100 posts. This has NOTHING to do with transformers, combining currents or anything else. Clear your mind of your preconceptions and read what is written. The statement was made by myself and others that the panel could SUPPLY 120 amps at 120 volts. You and your friend do not understand the basis of this statement and I do not think you ever will. You were given a chance to have your theory proven on a professional electrical forum but did not avail yourself of that opportunity, but as Robert said, you did avoid the embarrassment.
I have removed the transformer for you. I have also double-ended the arrows for you. Before you and your miss guided flock can analyse a circuit you will have to understand the basics of electricity.

42. ## Re: Determining the amperage mat a main disconnect fuse block

You obviously do not want to understand this simple subject. Hopefully your eyes will open one day.

43. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Vern Heiler
I have removed the transformer for you. I have also double-ended the arrows for you. Before you and your miss guided flock can analyse a circuit you will have to understand the basics of electricity.

This is not about the current on the neutral.

I will ask you a straight forward question. How much current does it take to open a 60 amp fuse or breaker? Does this matter whether the breaker is a single or double pole? If BOTH legs of the double pole breaker opened due to overload, how much current was flowing?

44. ## Re: Determining the amperage mat a main disconnect fuse block

The source of all the contention was started in Post #9.

Originally Posted by Roland Miller
I guess you will have to show me where you could measure 120 amps on a 3-wire, 120/240, single phase transformer with the 120 volt phase/circuit each pulling 60 amps
This is also where the transformer sidetrack came from.

No one ever said you could measure 120 amps on ONE conductor. It was said that there was 120 amps of capacity available.

Originally Posted by Robert Meier
Those two guys are incorrect and you're right. The feeder is 60 amp @ 240 volts (or 208). At 120 volts you would have a capacity of 120 amps but that nothing to do with the rating of the feeder.

45. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
"Fixed this for you. At 120 volts you still only have 60 amps available per leg."

You do see 60 amps on each leg, but they are the same 60 amps as we have been saying since the beginning! NOT PER!

You asked for and authority to settle this, I thought Kirchhoff would be enough for even you!

46. ## Re: Determining the amperage mat a main disconnect fuse block

Robert, I hope you don't expect an answer for your latest question. The question you posted days ago still has not been answered.

Vern, how do you explain the that half the panel will still function properly even with one fuse removed? How much capacity does that half have?

47. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Robert Meier
No laws of physics required, no diagrams required. I'll try one more example.

60 amp, 1Ø, 3 wire, 120/240 volt service with no loads:

How many 120 volt 60 amp heaters can I connect?

How many 240 volt 60 amp heaters can I connect?
The laws of physics does not apply to you, very interesting!

You are talking power again, you know I have already asked you to talk power OR current.

I am going to do some vector analysis. CE (center of effort) plotted against CLR (center of lateral resistance, to find DMG (distance made good).....I m going sailing.

48. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Vern Heiler
The laws of physics does not apply to you, very interesting!

.
Again an answer is taken out of context. It does not require the application of any laws of physics. It does not mean they do not apply. All you need is written on the breaker handle or fuse label and a calculator. This has always been a simple math problem.

49. ## Re: Determining the amperage mat a main disconnect fuse block

I have followed this thread very closely and have found very educational....and confusing .

My question is for Jim & Robert to help me, and probably others, understand the argument. Are you saying that a 120 amp balanced load would not trip the 60 amp OCPD?

I apologize in advance if this is a stupid question.

50. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Chris McIntyre
I have followed this thread very closely and have found very educational....and confusing .

My question is for Jim & Robert to help me, and probably others, understand the argument. Are you saying that a 120 amp balanced load would not trip the 60 amp OCPD?

I apologize in advance if this is a stupid question.
Not a stupid question. It appears you understand this better than others.

There are 2 ungrounded legs in a typical home panel that feed alternating fingers on the bus bars. Using a balanced 120 amp 120 volt load across the 2 legs would have each leg carrying 1/2 the current or 60 amps. This could be as simple as three fully loaded 20 amp 120 volt circuits operating on each leg of the panel.

If the load were 240 volts the breaker or fuse will open when the current exceeds 60 amps.The breaker or fuse would open when either or both sides saw more than 60 amps. In an extremely unbalanced load where everything was on one leg and exceeded 60 amps the breaker would open even with the other leg carrying 0 amps.

The key factor that has been ignored numerous times is that the number of amps will change with the voltage. For example 600 watts at 120 volts = 5 amps, change the voltage to 240 volts and the amps drop to 2.5. Using a higher voltage allows for smaller wire sizes to be used.

Last edited by Jim Port; 08-10-2013 at 02:16 PM.

51. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
Not a stupid question. It appears you understand this better than others.

There are 2 ungrounded legs in a typical home panel that feed alternating fingers on the bus bars. Using a balanced 120 amp 120 volt load across the 2 legs would have each leg carrying 1/2 the current or 60 amps. This could be as simple as three fully loaded 20 amp 120 volt circuits operating on each leg of the panel.

If the load were 240 volts the breaker or fuse will open when the current exceeds 60 amps.The breaker or fuse would open when either or both sides saw more than 60 amps. In an extremely unbalanced load where everything was on one leg and exceeded 60 amps the breaker would open even with the other leg carrying 0 amps.

The key factor that has been ignored numerous times is that the number of amps will change with the voltage. For example 600 watts at 120 volts = 5 amps, change the voltage to 240 volts and the amps drop to 2.5. Using a higher voltage allows for smaller wire sizes to be used.
Still mixing power and current huh!

In practical terms, the ampere is a measure of the amount of electric charge passing a point in an electric circuit per unit time with 6.241 × 1018electrons, or one coulombper second constituting one ampere.

59 amps will pass through a 60 amp breaker just fine. It does not matter if it is being pushed by 1 volt or 10,000 volts it will not trip. When it reaches 60 amps it will trip. Voltage is irrelevant. Tripping of a breaker or blowing of a fuse is due to power developed across the OCP device. All conductors have resistance and the power is the product of current squared times resistance. Resistance and current are the only two things a fuse knows. The voltage ratting on a fuse or circuit breaker is the voltage that the blown fuse will not arc across after it has blown.

This discussion has been about amps from the beginning, even though Jim & Robert keep asking questions regarding or insisting that power calculations be used.

There will never be more than 60 amps at one time on a 3-wire circuit protected by 60 amp breakers and I don't care if there are 100 breakers or fuses in the circuit.

Last edited by Vern Heiler; 08-10-2013 at 03:17 PM. Reason: reft and light mixed up

52. ## Re: Determining the amperage mat a main disconnect fuse block

Voltage is not irrelevant. The voltage something operates at determines the amp draw as I illustrated above showing the 600 watt load and the difference in amps being halved by the doubling of the voltage.

BTW, you appear to have little or no knowledge of breaker trip curves or the UL allowance for variation. Depending on the rate of rise a breaker will hold 125% for over an hour. It does not trip as soon as it sees 60.1 amps.

53. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
Voltage is not irrelevant. The voltage something operates at determines the amp draw as I illustrated above showing the 600 watt load and the difference in amps being halved by the doubling of the voltage.

BTW, you appear to have little or no knowledge of breaker trip curves or the UL allowance for variation. Depending on the rate of rise a breaker will hold 125% for over an hour. It does not trip as soon as it sees 60.1 amps.
Still can't see or admit that you are talking about power after I have posted the definition of current. And yes I do know about breaker ratings and the difference in a standard and slow blow fuse. Clouding the discussion with this or PF or current lag, would not help for anyone to understand the basics, and certainty didn't help you! Talk current or go home!

54. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Robert Meier
No such thing as a stupid question. Since you've been following this thread very closely and choose to ask Jim and myself for further information I'll assume that you value our knowledge. If you want distractions and hyperbole try to follow some of the other drawings, charts, copy and paste stuff from the Internet and other misinformation in this thread.

What we have said from the beginning is that if you have a 60 amp 1Ø, 120/240 volt system that you could connect either one 60 amp, 240 volt load or two 60 amp, 120 volt loads.
Post #4

"Those two guys are incorrect and you're right. The feeder is 60 amp @ 240 volts (or 208). At 120 volts you would have a capacity of 120 amps but that nothing to do with the rating of the feeder."

Post #10

"
Think about it, you could try to pull 75 amps on one leg of the 2 pole breaker while the other leg is at 0. Depending on the trip curve, the breaker will trip. You could also have each of the 2 hots pulling 60 amps and the breaker does not trip. 60 + 60=120."

Last edited by Vern Heiler; 08-11-2013 at 01:04 PM. Reason: and post 10

55. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port

This is not about the current on the neutral.

I will ask you a straight forward question. How much current does it take to open a 60 amp fuse or breaker? 60 Amps Does this matter whether the breaker is a single or double pole You don't know the difference? It would need to be a 2-pole....If BOTH legs of the double pole breaker opened due to overload, how much current was flowing? 60 Amps
It would be 60 amps, if it were more you could measure it.. Only in New England would it take more than 60 amps.............

- - - Updated - - -

56. ## Re: Determining the amperage mat a main disconnect fuse block

Sorry Roland, that diagram you posted was by Vern, not me.

It would not have to be a double pole in order to trip. The OP asked about a fused pullout disconnect. If there was more than 60 amps on one leg the fuse would still open. More than 60 amps on a double pole breaker would also cause the breaker to open.

57. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
Sorry Roland, that diagram you posted was by Vern, not me.

It would not have to be a double pole in order to trip. The OP asked about a fused pullout disconnect. If there was more than 60 amps on one leg the fuse would still open. More than 60 amps on a double pole breaker would also cause the breaker to open.

Thanks for agreeing with me. That's 4 times now. Are you convinced or still thrashing around with the laws of physics?

58. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
Sorry Roland, that diagram you posted was by Vern, not me.

It would not have to be a double pole in order to trip. The OP asked about a fused pullout disconnect. If there was more than 60 amps on one leg the fuse would still open. More than 60 amps on a double pole breaker would also cause the breaker to open.
Jim, don't try to spin this around! That was a simple diagram showing that YOUR interpretation of what is going on (120 amps) violates Kirchhoff's first law!

59. ## Re: Determining the amperage mat a main disconnect fuse block

I understand this issue quite well. Some just can't get past the fact that no one said you could measure the 120 amps on one conductor and that two conductors carrying 60 amps each equal 120 amps of capacity.

60. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
I understand this issue quite well. Some just can't get past the fact that no one said you could measure the 120 amps on one conductor and that two conductors carrying 60 amps each equal 120 amps of capacity.
If you understand this so well, just show us where each of the 60 amps goes. You can use my diagram or the one I stole from Code Check, we can probably get a group rate from the lawyer.

61. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
I understand this issue quite well. Some just can't get past the fact that no one said you could measure the 120 amps on one conductor and that two conductors carrying 60 amps each equal 120 amps of capacity.
Some of you may be wondering what this discussion is all about. At times I wonder myself.

Jim and Robert are using a mix of amps and volt-amps to try to prove that 120 amps of "loads or capacity" exists somewhere in the circuit under discussion(120/240 volt-single phase), but admit they cannot measure it. This should raise a big question mark for all of you...

Here are two definitions of "load" from two major publication textbooks.(one of which I am a technical editor of).

"Load-the power consumed by a piece of equipment or a circuit while performing its function."

"Load-The current demand on the output of a circuit."

And a quote from one--"There is a limit on the LOAD (current demand) that can be placed on any circuit, in many cases, this limit is indicated by the current rating of the circuit's fuse or circuit breaker."

quotes from --Delmar's Standard Textbook of Electricity and Introduction to Electricity-Paynter & Boydell

It was pointed out to me that my example might be confusing. I kept it real-world so 5- 20 amp circuit breakers or fuses. Three on A phase and two on B phase results in the loading I described. Certainly a completely balanced circuit would result in 0 amps on the neutral..

Last edited by Roland Miller; 08-12-2013 at 01:03 PM.

62. ## Re: Determining the amperage mat a main disconnect fuse block

Of course, the other issue here is the one of "self appointed experts" and who should you believe.

Jim, Robert, Jerry Peck, and HG all answer questions and promote them selves as "experts". The difference comes when someone disagrees with them. They then spin the question, redirect the issue, try to send you off to check with "someone that knows", accuse you of costing some innocent group money, say you can't even answer simple questions and are spreading misinformation. And call you a TROLL. And often they resort to insults and directly questioning whether you know anything about the subject. ..and add to that--They have checked with their buddy's and they agree with them.

This sure sounds a lot like BULLYING to me!

63. ## Re: Determining the amperage mat a main disconnect fuse block

You were right Robert, here we are over 200 posts and some still do not understand and are now blaming us for bullying them. If telling people the facts is bullying, so be it.

64. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Robert Meier
You know Jim I just asked a few simple questions in this thread and for the most part have yet to get a direct response. For example, here are two direct questions, look at the response:

I can make this one even easier, only a one word answer required:

TRUE or FALSE?

60 amp, 1Ø, 3 wire, 120/240 volt service with no loads:

This service have the capacity to supply one 240 volt, 60 amp heater or two 120 volt, 60 amp heaters.
E X I = P and the answer when asked of POWER is yes. All done with the same 60 amps of current.

Now answer the one I have been asking from the beginning. Can you show us where the two 60 amp currents you say are available go in a circuit?

65. ## Re: Determining the amperage mat a main disconnect fuse block

Originally Posted by Jim Port
You were right Robert, here we are over 200 posts and some still do not understand and are now blaming us for bullying them. If telling people the facts is bullying, so be it.

Of course, the other issue here is the one of "self appointed experts" and who should you believe.

Jim, Robert, Jerry Peck, and HG all answer questions and promote them selves as "experts". The difference comes when someone disagrees with them. They then spin the question, redirect the issue, try to send you off to check with "someone that knows", accuse you of costing some innocent group money, say you can't even answer simple questions and are spreading misinformation. And call you a TROLL. And often they resort to insults and directly questioning whether you know anything about the subject. ..and add to that--They have checked with their buddy's and they agree with them.

This sure sounds a lot like BULLYING to me! yup

- - - Updated - - -

Originally Posted by Robert Meier
You know Jim I just asked a few simple questions in this thread and for the most part have yet to get a direct response. For example, here are two direct questions, look at the response:

I can make this one even easier, only a one word answer required:

TRUE or FALSE?

60 amp, 1Ø, 3 wire, 120/240 volt service with no loads:

This service have the capacity to supply one 240 volt, 60 amp heater or two 120 volt, 60 amp

heaters.

Some of you may be wondering what this discussion is all about. At times I wonder myself.

Jim and Robert are using a mix of amps and volt-amps to try to prove that 120 amps of "loads or capacity" exists somewhere in the circuit under discussion(120/240 volt-single phase), but admit they cannot measure it. This should raise a big question mark for all of you...

Here are two definitions of "load" from two major publication textbooks.(one of which I am a technical editor of).

"Load-the power consumed by a piece of equipment or a circuit while performing its function."

"Load-The current demand on the output of a circuit."

And a quote from one--"There is a limit on the LOAD (current demand) that can be placed on any circuit, in many cases, this limit is indicated by the current rating of the circuit's fuse or circuit breaker."

quotes from --Delmar's Standard Textbook of Electricity and Introduction to Electricity-Paynter & Boydell

It was pointed out to me that my example might be confusing. I kept it real-world so 5- 20 amp circuit breakers or fuses. Three on A phase and two on B phase results in the loading I described. Certainly a completely balanced circuit would result in 0 amps on the neutral..

Good job Vern!!

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