adding 8 1000w loads to a 100A service

[benmin]

Have a customer that wants to add receptacles to operate 8 1000w 120V laminate machines in his basement. wants to know if it can be done with his 100A service. it is a 1200 sq/ft home with 2 kitchen circuits, 1 washer, 1 Garbage disp, 1 Dish, 1 range, 1 dryer, no electric heat or AC. Do not know the VA of the appliances.

Not so confident in my calculation

 

[Tony S]

What have you calculated so far?

 

[benmin]

came up with 137. guessing at the dryer and stove.

 

[Tony S]

Is this not 120-N-120 ?

 

[benmin]

correct

 

[Electric-Light]

Have a customer that wants to add receptacles to operate 8 1000w 120V laminate machines in his basement. wants to know if it can be done with his 100A service. it is a 1200 sq/ft home with 2 kitchen circuits, 1 washer, 1 Garbage disp, 1 Dish, 1 range, 1 dryer, no electric heat or AC. Do not know the VA of the appliances.

Not so confident in my calculation

How permanent is this?

I suppose a 50A welder receptacle can be added, then utilize it with a spider box pod built into four duplexes each setup as MWBC with each duplex getting its own 15A two-pole breaker. A properly added 50A receptacle can possibly have some value to the next HO, but WTF would someone do with eight 120v outlets in one cluster each on its own breaker?

And the spider box does give him the ability to get lots of 15A outlets from from a 50A outlet should he move somewhere else.

240v 50A is split into four 15A 120v on one side, four 15A 120v on the other side.
If ANY one receptacle exceeds 15A, one of the four 15A two pole trips and take out two outlets. If combined total causes either pole to exceed 50A, the breaker in panel trips.

When all eight are plugged in and powered up, it will be 8kW and current will be as if it was 240v. So, it's only 33.3A.

 

[Tony S]

correct

I?ll assume 120-N-120 is correct which @100A gives you 13.8KVA to play with in total.

Will all the laminators ran continuously? Are they thermostatically controlled? Can a diversity factor be applied?
With all machines running with thermostatic control the load will at an educated guess be around 5KVA or even less.

 

[Barbqranch]

Are they really laminating machines, or are they grow lights? If grow lights, then continuous operation.

 

[Tony S]

And I thought I had a suspicious mind.

 

[GoldDigger]

And I thought I had a suspicious mind.

Laminate, Luminate, close enough.... :angel:


Reminds me of the Holmes on Homes episode where there was a bank of about 20 duplex receptacles on four MWBCs next to the basement stairs, and a garden hose attached to the plumbing under the sink of the basement bathroom.

 

[Electric-Light]

Laminate, Luminate, close enough.... :angel:


Reminds me of the Holmes on Homes episode where there was a bank of about 20 duplex receptacles on four MWBCs next to the basement stairs, and a garden hose attached to the plumbing under the sink of the basement bathroom.

My own private 50kVA 7200v to 480v transformer please.

 

[kwired]

The thing about this setup is, does a single person utilize said equipment? Does all of them run at same time if only one person is using them? Even if they do run at same time, they likely cycle to maintain temperature and maybe do not put as continuous of a draw on the supply as one may think. Then one must consider what other load may likely be in the house at same time these are loaded, again if a single person lives there and is operating their own business from home - maybe not much else load would be typically running at same time. Of course NEC art 220 doesn't necessarily recognize everything I said here, but reality is often you could run such items from the 100 amp feed and never trip main overcurrent protection because of the low load diversity that is typical for dwellings in the first place.

 

[Electric-Light]

The thing about this setup is, does a single person utilize said equipment? Does all of them run at same time if only one person is using them? Even if they do run at same time, they likely cycle to maintain temperature and maybe do not put as continuous of a draw on the supply as one may think. Then one must consider what other load may likely be in the house at same time these are loaded, again if a single person lives there and is operating their own business from home - maybe not much else load would be typically running at same time. Of course NEC art 220 doesn't necessarily recognize everything I said here, but reality is often you could run such items from the 100 amp feed and never trip main overcurrent protection because of the low load diversity that is typical for dwellings in the first place.

Single person utilize eight laminate machines? unpossible.
Do they use plain resistive elements or ballasted arc lamps? :ashamed1:

 

[Rampage_Rick]

My own private 50kVA 7200v to 480v transformer please.

Had one of those up the hill from me. They tapped right into the 14.4kV aerial primary and transitioned to a 350 foot underground run. At the end there was a 100kVA pad feeding a 12-foot long panel in an underground bunker. Somebody was definitely working off the clock...



It was built sometime between Sept '03 and March '04 according to Google Earth. Wasn't busted until Sept '09
http://www.cbc.ca/news/canada/briti...rground-grow-op-busted-in-chilliwack-1.815729

 

[Electric-Light]

Wasn't busted

"wasn't" busted or did they wait to grow the loss amount ?
"they estimated more than $400,000" of electricity.

If a group of people skipped fares in what would've retailed $1,000 on a deserted line, that'll give them a much needed excuse to ask for funding or raise fares so they can say the $1,000 on seats that wouldn't have sold anyways is the same as a smashed out window that costs $1,000 to repair.

Pretty sure the cost to BC Hydro didn't increase anything close to $400,000. They don't pay for fuel. I'm sure they're itching for a reason to ask for a rate hike to increase the revenue stream to pay for other stuff :lol:

 

[Electric-Light]

Wasn't busted

"wasn't" busted or did they wait to grow the loss amount ?
"they estimated more than $400,000" of electricity.

If a group of people skipped fares in what would've retailed $1,000 on a deserted line, that'll give them a much needed excuse to ask for funding or raise fares so they can say the $1,000 on seats that wouldn't have sold anyways is the same as a smashed out window that costs $1,000 to repair.

Pretty sure the cost to BC Hydro didn't increase anything close to $400,000. They don't pay for fuel. I'm sure they're itching for a reason to ask for a rate hike to increase the revenue stream to pay for other stuff :lol:

If there wasn't the legal issue and if they pay the bills, these are angel customers, like data centers. They love customer owned transformers that can feed directly from primary with plenty of reserve capacity and away from the city core. It's a steady revenue stream. 80kW demand at 100% utilization factor of 24/7/365 means 701MWh a year or a steady revenue stream of $14,000/yr even at 2c/kWh.

If you use 18.15kWh/day:
They love people who use 250W bulbs lit up around the clock. You're making revenue on 18.15kWh with only 250VA of capacity used up.

They hate customers who use 150W all day long but wants to use 5,000W for 3 hours at 5PM to 8PM. You're only making 18.15kWh of revenue, but using up 5kVA of capacity in the transformer which has the capacity to sell 120kWh/day

 

[benmin]

The thing about this setup is, does a single person utilize said equipment? Does all of them run at same time if only one person is using them? Even if they do run at same time, they likely cycle to maintain temperature and maybe do not put as continuous of a draw on the supply as one may think. Then one must consider what other load may likely be in the house at same time these are loaded, again if a single person lives there and is operating their own business from home - maybe not much else load would be typically running at same time. Of course NEC art 220 doesn't necessarily recognize everything I said here, but reality is often you could run such items from the 100 amp feed and never trip main overcurrent protection because of the low load diversity that is typical for dwellings in the first place.

Guy uses laminating machines occasionally as part of his business for comic books. wants to have 8 to use at the same time since he can only do it for short periods of time when he can. They take about 10min to heat up and do there thing so he doesn't have time to do then 1 or 2 at a time. Looking at what he has for loads, I see no issue. No electric heat, sump pump, electric hot water or ac. just a small house. Thought I would do a calc and see how close it was (don't do calcs often so not that great at it). I came up a lot higher then What I would expect for a small house like this so I think I made an error. What would you use for numbers for a range, dryer, disposal and dish you did not know the nameplate ratings are?

 

[kwired]

Guy uses laminating machines occasionally as part of his business for comic books. wants to have 8 to use at the same time since he can only do it for short periods of time when he can. They take about 10min to heat up and do there thing so he doesn't have time to do then 1 or 2 at a time. Looking at what he has for loads, I see no issue. No electric heat, sump pump, electric hot water or ac. just a small house. Thought I would do a calc and see how close it was (don't do calcs often so not that great at it). I came up a lot higher then What I would expect for a small house like this so I think I made an error. What would you use for numbers for a range, dryer, disposal and dish you did not know the nameplate ratings are?

And as I mentioned earlier - if he is busy with his laminating projects chances are he is not cooking Thanksgiving dinner at the same time - something the NEC doesn't take into consideration in load calculations. Good chance he has little problems with the arrangement - especially if he lives there alone, if he has a family, roommates, etc. then you need to consider what others may be utilizing at same time. Also these machines would draw full power for about 10 minutes until warmed up then average load would drop some as they would only cycle as needed for maintenance of the heat level.

But do keep in mind that you will be adding quite a bit of heat to the space these are located in, so during heating season it gives heating equipment a break, but does add to needed cooling load or possibly at least add the need for an exhaust fan. Something else the NEC doesn't consider.

8000 watts of electric heat is plenty for heating some small homes.

 

[iwire]

I would say it would work.

I will also say it will not be NEC compliant.

 

[Tony S]

Guy uses laminating machines occasionally as part of his business for comic books. wants to have 8 to use at the same time since he can only do it for short periods of time when he can. They take about 10min to heat up and do there thing so he doesn't have time to do then 1 or 2 at a time. Looking at what he has for loads, I see no issue. No electric heat, sump pump, electric hot water or ac. just a small house. Thought I would do a calc and see how close it was (don't do calcs often so not that great at it). I came up a lot higher then What I would expect for a small house like this so I think I made an error. What would you use for numbers for a range, dryer, disposal and dish you did not know the nameplate ratings are?

Well that?s just spoilt some fun.

I can?t say for NEC codes but the loading gives me no concern.