Home owner calculation
- Thread starter Mdowdy@lsmech.com
- Start date
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What I can't get my head round is why you would need almost 100 kVA for a residence.
drktmplr12
Senior Member
- Location
- South Florida
- Occupation
- Electrical Engineer
:slaphead::slaphead::slaphead::slaphead::slaphead:
i can only express my outrage to this article in emojis or memes. :blink:
i can only express my outrage to this article in emojis or memes. :blink:
growler
Senior Member
- Location
- Atlanta,GA
200 amp service is less than 50 KVA.
They don't size the transformers that big because you are normally not drawing anywhere near that much current.
MAC702
Senior Member
- Location
- Clark County, NV
So did you install this and there is a complaint? Are they holding up payment for it?
Don't do another load calc for free unless it's just the easier way to get paid for the job.
Welcome to a real electricians' forum.
Don't do another load calc for free unless it's just the easier way to get paid for the job.
Welcome to a real electricians' forum.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
It looks like this is the source of the calculation done by the homeowner:
https://www.hunker.com/12285752/how-to-calculate-a-breaker-panel-load
I'm tempted to write to their editorial team, and ask how much they would pay for a _correct_ calculation
-Jon
https://www.hunker.com/12285752/how-to-calculate-a-breaker-panel-load
I'm tempted to write to their editorial team, and ask how much they would pay for a _correct_ calculation
-Jon
It looks like this is the source of the calculation done by the homeowner:
https://www.hunker.com/12285752/how-to-calculate-a-breaker-panel-load
I'm tempted to write to their editorial team, and ask how much they would pay for a _correct_ calculation
-Jon
I like why they think to multiply by .80; power surges...
We should notify the NFPA; This would have been a lot easier method in apprentice school! And the wire guys would love it!
Your mobile home with a 600 amp service!
romex jockey
Senior Member
- Location
- Vermont
- Occupation
- electrician
I usually don't, It's my way or the highway as a hired sprak....
That can be problematic....
W/out looking, i'm sure it's lousy with disclaimers.....
But i digress , what if you exist w/in a screwed up permit process that allows DIY intervention? I.E.--- I can walk away , but the state inspectors can not. It frustrates the daylights outta them to have to deal with these sorts
~RJ~
growler
Senior Member
- Location
- Atlanta,GA
It looks like this is the source of the calculation done by the homeowner:
https://www.hunker.com/12285752/how-to-calculate-a-breaker-panel-load
I'm tempted to write to their editorial team, and ask how much they would pay for a _correct_ calculation
-Jon
I think they should remove the article before it causes any more problems.
growler
Senior Member
- Location
- Atlanta,GA
This is the calculation I received from a homeowner. The house is roughly 3000 S.F single family with attached garage. Gas heat, Gas water heater (tankless), Gas cooking. How do you respond when this math is on DIY internet?
Thanks,
Mike
Mike there is still one thing that bothers me. The article only tells the HO to get a count of the breakers and their amperage. So the breaker count is possibly real.
If they have gas heat, gas W/H, gas cooking then why are there 2 ea. 30 amp breakers, 2 ea, 40 amp breaker and 2 ea. 60 amp breakers. I assume that one of the 30s is a clothes dryer and the 2 ea. 40s are for AC units but what are the 2 ea. 60 amp breakers for? And there is still an extra 30 that's not accounted for.
kwired
Electron manager
- Location
- NE Nebraska
Pretty much the theme of this thread.
Or a scam to sell them an upgrade, bet they didn't put in true 840+ amp service if they did do any upgrading.
Most dwellings don't need that capacity. Occasional large ones do. I had one with 60 kW of electric heat plus two laundry rooms, 5 4.5 kW water heaters, and then 10,000+ square feet of space with otherwise relatively normal loads. Can't remember if POCO set a 75 or a 100 kVA transformer. I ran 4 sets of 200 amp conductor to 4 200 amp service disconnects on that one, was better design choice as it was less cost on gear but maybe extra conductor made up that difference, plus left more future capacity if ever needed than putting on a single 400 amp main which would have been enough from recollection but wouldn't have had much room for additions.
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
And I like to strongly discourage such statements. With 200 amps on phase A and 200 amps on phase B, you have a "total" of 200 amps. For the moment let us assume that the loads are balanced. Current that leaves the panel on phase A will return to the panel on phase B. It is the same current.
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
His claim is based on a meaningless collection of data. The service is not undersized, there is no code violation, and there is no safety hazard. If he wants a 320 amp service, give him a cost proposal for the upgrade. You own them nothing.
How many 3000 square foot houses have 200 amp services. Many!
Plus, it has Gas, which makes this even more obvious that you count on this service as fine.
You can only put so much crap in a 3000 square house and have it turned on at the same time.
One solution, change all the breakers to 15 amp!
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
Of course, if they really are using $5000 worth of electricity each month, then they shouldn't quibble about paying a few K for an upgraded service
(If the DIY calculation was correct, then they would be using some 72kW, at 24 hours per day 30 days a month, it adds up pretty quick ....
-Jon
(If the DIY calculation was correct, then they would be using some 72kW, at 24 hours per day 30 days a month, it adds up pretty quick ....
-Jon
growler
Senior Member
- Location
- Atlanta,GA
To change breakers to 15 amps doesn't change anything in a load calculation. General lighting load is calculated at 3 VA pr sq ft . Small appliance circuit at 1500 VA each.
AC load at FLA on name plate and not breaker size.
You can put lots of things in a 3000 sq ft house that will cause the load to go way up.
Tankless electric water heater.
Heat pump with electric heat strip back up or even worse a big electric furnace.
Couple of of the big tesla car chargers
hot tub or pool heater (if electric)
What I'm getting at is the size of the house has less to do with the service load than major appliance loads.
MAC702
Senior Member
- Location
- Clark County, NV
And why does it differentiate the two sides of the panel?
If you do the calculation the way hunker is doing it, it sure will. I was being sarcastic...
kwired
Electron manager
- Location
- NE Nebraska
If they think $5k a month is too much, then they will quibble if the energy bill doesn't decrease after upgrading the service/equipmentOf course, if they really are using $5000 worth of electricity each month, then they shouldn't quibble about paying a few K for an upgraded service
(If the DIY calculation was correct, then they would be using some 72kW, at 24 hours per day 30 days a month, it adds up pretty quick ....
-Jon
Instead you need to sell them those magic black boxes that will reduce their energy bill
Sure it does put that heat pump on a 15 amp breaker instead of a 40 and the load will only run for a little while before it is automatically reduced by a tripping breaker
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