# Right or wrong? Charlie would be proud **URL:** \ **Category:** Electrical Inspections\ **Created:** [February 20, 2013, 11:06pm UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689 "2013-02-20T23:06:48Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![sfogarty](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/sfogarty/32/58235_2.png) [@sfogarty](https://forum.nachi.org/u/sfogarty)\ **Post date:** [February 20, 2013, 11:06pm UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/1 "2013-02-20T23:06:48Z")
New construction 1800 sf condo 125 amp service All electric, no gas 10kw heat pump, compressor, water heater and range all running. No dryer to test. Got 126 amp draw. šŸ˜ƒ ![003.jpg](https://global.discourse-cdn.com/internachi/original/3X/9/d/9db473da4fdb0f91a27f3b8ca16044e3d73c7102.jpeg) ---
**Author:** ![Jim\_Port](https://avatars.discourse-cdn.com/v4/letter/j/bc8723/32.png) [@Jim\_Port](https://forum.nachi.org/u/Jim_Port)\ **Post date:** [February 20, 2013, 11:46pm UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/2 "2013-02-20T23:46:45Z")
Considering the artificial conditions you created I donā€™t see any value to those figures. ---
**Author:** ![sfogarty](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/sfogarty/32/58235_2.png) [@sfogarty](https://forum.nachi.org/u/sfogarty)\ **Post date:** [February 20, 2013, 11:51pm UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/3 "2013-02-20T23:51:26Z")
> [@Jim\_Port](#): > > Considering the artificial conditions you created I donā€™t see any value to those figures. Why not? explain? My review with a master electrican said it was incorrect. ---
**Author:** ![rmeier2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/rmeier2/32/59909_2.png) [@rmeier2](https://forum.nachi.org/u/rmeier2)\ **Post date:** [February 21, 2013, 12:16am UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/4 "2013-02-21T00:16:01Z")
Did that master electrician do a load calculation? ---
**Author:** ![cevans](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cevans/32/244194_2.png) [@cevans](https://forum.nachi.org/u/cevans)\ **Post date:** [February 21, 2013, 12:26am UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/5 "2013-02-21T00:26:33Z")
> [@Jim\_Port](#): > > Considering the artificial conditions you created I donā€™t see any value to those figures. Because people never use use hot water cook and heat at the same time? My 200A mains usually trip once or twice a winter. I would have liked to know that they might do that when I bought the house. ---
**Author:** ![wwilson3](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/wwilson3/32/58197_2.png) [@wwilson3](https://forum.nachi.org/u/wwilson3)\ **Post date:** [February 21, 2013, 12:28am UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/6 "2013-02-21T00:28:17Z")
I say it is wrong . And yes all the above could be on , I would say someone fu ---
**Author:** ![sfogarty](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/sfogarty/32/58235_2.png) [@sfogarty](https://forum.nachi.org/u/sfogarty)\ **Post date:** [February 21, 2013, 12:30am UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/7 "2013-02-21T00:30:17Z")
> [@Robert\_Meier](#): > > Did that master electrician do a load calculation? We went over the basic stuff, but it was inconsistent with almost everything else built in that size range with all electric and no gas. ---
**Author:** ![jpope](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jpope/32/59425_2.png) [@jpope](https://forum.nachi.org/u/jpope)\ **Post date:** [February 21, 2013, 12:40am UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/8 "2013-02-21T00:40:02Z")
I donā€™t do load-calcs, but my understanding is that the service should be sized to accommodate a percentage (not 100%) of the maximum potential load. There is a whole ā€œformulaā€ to a proper load calculation, which is above my pay grade šŸ˜ƒ I wouldnā€™t make a judgement call on this without running past someone who knows how to do these calculations. ---
**Author:** ![sfogarty](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/sfogarty/32/58235_2.png) [@sfogarty](https://forum.nachi.org/u/sfogarty)\ **Post date:** [February 21, 2013, 12:49am UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/9 "2013-02-21T00:49:03Z")
> [@jpope](#): > > I donā€™t do load-calcs, but my understanding is that the service should be sized to accommodate a percentage (not 100%) of the maximum potential load. There is a whole ā€œformulaā€ to a proper load calculation, which is above my pay grade šŸ˜ƒ > > I wouldnā€™t make a judgement call on this without running past someone who knows how to do these calculations. The only call I made is a secondary review to ensure proper sizing. NO repairs or corrections at this point, just really unusual for the build. Talked with a state inspector who are the ones who make the calls in regards to this, and he said he would have to come take a look at this one once he found out all the information. ---
**Author:** ![evandeven](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/evandeven/32/373798_2.png) [@evandeven](https://forum.nachi.org/u/evandeven)\ **Post date:** [February 21, 2013, 1:25am UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/10 "2013-02-21T01:25:20Z")
> [@sfogarty](#): > > Why not? explain? > My review with a master electrican said it was incorrect. When I do my inspections, everything is on for the very reason Chuck mentioned. I have had a few homes where the main did trip. There is an excel load calculation sheet out on the net. I have a copy. ---
**Author:** ![Jim\_Port](https://avatars.discourse-cdn.com/v4/letter/j/bc8723/32.png) [@Jim\_Port](https://forum.nachi.org/u/Jim_Port)\ **Post date:** [February 21, 2013, 1:46am UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/11 "2013-02-21T01:46:17Z")
A demand load calculation is the only proper way to size a service. Not a trumped up lets turn everything on and see if the main trips. Using that method you could say every circuit in the house is too small by plugging in multiple space heaters on high. ---
**Author:** ![Jim\_Port](https://avatars.discourse-cdn.com/v4/letter/j/bc8723/32.png) [@Jim\_Port](https://forum.nachi.org/u/Jim_Port)\ **Post date:** [February 21, 2013, 1:48am UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/12 "2013-02-21T01:48:35Z")
> [@cevans](#): > > My 200A mains usually trip once or twice a winter. I would have liked to know that they might do that when I bought the house. Have you checked the ampacity being drawn or for other problems in the panel? Sounds like it is time for some diagnostics. A properly sized service should not be doing this. A breaker will typically hold 125% for over an hour depending on how fast it gets to capacity. ---
**Author:** ![canderson5](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/canderson5/32/1814_2.png) [@canderson5](https://forum.nachi.org/u/canderson5)\ **Post date:** [February 21, 2013, 1:49am UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/13 "2013-02-21T01:49:57Z")
Am I missing something? How is this a question of right or wrong? If there is 126 amp draw coming through a 125 amp service without the main tripping, how is that not wrong? ---
**Author:** ![canderson5](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/canderson5/32/1814_2.png) [@canderson5](https://forum.nachi.org/u/canderson5)\ **Post date:** [February 21, 2013, 1:50am UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/14 "2013-02-21T01:50:49Z")
> [@Jim\_Port](#): > > Have you checked the ampacity being drawn or for other problems in the panel? Sounds like it is time for some diagnostics. A properly sized service should not be doing this. > > \*\* A breaker will typically hold 125% for over an hour depending on how fast it gets to capacity\*\*. Ah, you just answered it. šŸ™‚ ---
**Author:** ![Jim\_Port](https://avatars.discourse-cdn.com/v4/letter/j/bc8723/32.png) [@Jim\_Port](https://forum.nachi.org/u/Jim_Port)\ **Post date:** [February 21, 2013, 1:51am UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/15 "2013-02-21T01:51:54Z")
> [@canderson5](#): > > Am I missing something? How is this a question of right or wrong? If there is 126 amp draw coming through a 125 amp service without the main tripping, how is that not wrong? Search ā€œbreaker trip curvesā€. As I said above a breaker will hold quite a bit more than its rating for a substantial period of time. A breaker simply does not trip at .1 over the rating. ---
**Author:** ![Jim\_Port](https://avatars.discourse-cdn.com/v4/letter/j/bc8723/32.png) [@Jim\_Port](https://forum.nachi.org/u/Jim_Port)\ **Post date:** [February 21, 2013, 2:00am UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/16 "2013-02-21T02:00:15Z")
> [@sfogarty](#): > > New construction 1800 sf condo 125 amp service > All electric, no gas > 10kw heat pump, compressor, water heater and range all running. No dryer to test. > Got 126 amp draw. šŸ˜ƒ Sizes out to 112 amp service. Note: 100 is the smallest allowed for a dwelling. ---
**Author:** ![sfogarty](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/sfogarty/32/58235_2.png) [@sfogarty](https://forum.nachi.org/u/sfogarty)\ **Post date:** [February 21, 2013, 2:16am UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/17 "2013-02-21T02:16:32Z")
> [@Jim\_Port](#): > > Sizes out to 112 amp service. Note: 100 is the smallest allowed for a dwelling. Wow thats the best answer yet. Thanks Jim. šŸ˜ƒ What always kills me is that electrical disscusion always seem to find lots who donā€™t agree. One person tells me its wrong, the next one says it s fine, etc. I could only imagine what it must be like to sit around at some convention and listen to everyone hash it out. ---
**Author:** ![rmeier2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/rmeier2/32/59909_2.png) [@rmeier2](https://forum.nachi.org/u/rmeier2)\ **Post date:** [February 21, 2013, 2:24am UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/18 "2013-02-21T02:24:00Z")
> [@canderson5](#): > > Am I missing something? How is this a question of right or wrong? If there is 126 amp draw coming through a 125 amp service without the main tripping, how is that not wrong? It may not be wrong because the testing procedure was flawed. Standard load calculations take into account load diversity where not every given load will be on at the same time. The test used here lacks diversity. ---
**Author:** ![canderson5](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/canderson5/32/1814_2.png) [@canderson5](https://forum.nachi.org/u/canderson5)\ **Post date:** [February 21, 2013, 2:32am UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/19 "2013-02-21T02:32:20Z")
> [@Robert\_Meier](#): > > It may not be wrong because the testing procedure was flawed. Standard load calculations take into account load diversity where not every given load will be on at the same time. The test used here lacks diversity. Is the assumption that a load like Sean applied would not remain for the length of time needed to trip the main (e.g. the water heater would cycle off, the dryer cycle would end) so itā€™s not logical to assume that load in a normal household setting? ---
**Author:** ![rhensel](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/rhensel/32/283_2.png) [@rhensel](https://forum.nachi.org/u/rhensel)\ **Post date:** [February 21, 2013, 2:36am UTC](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689/20 "2013-02-21T02:36:10Z")
Great find Sean. Gives you are reason to defer it to a licensed tradesman. Awesome job and way to go above and beyond. How did you ever think of using your meter? Your a freakin Genius! [Next page](https://forum.nachi.org/t/right-or-wrong-charlie-would-be-proud/75689.md?page=2)