800 amp service connect to (4) 200 amp panels

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Kevin Carpenter

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NE Missouri, USA
Hi all -

I'm new to the forum. I have decades of around-the-house&farm experience with wiring, but to date, I've maxed out with 200 amp services.

I'm about to put up a building that will eventually consume about 300kw of singe phase power 220V. The initial phase will be half of that. My local rural utility is helpful and confirmed they can (barely) support the 300kw. They have offered me (2) 167kw transformers, at their cost, including the underground power runs. All of my major internal needs will be 220V based, with an initial load from (80) 1372w computers (e.g. continuous load, no major inrush issues beyond what the power supplies will consume when powered up). That will eventually grow to (200) sources, IF my business model holds up to reality. Since the power supplies require 220v and a C13 plug, I intend to wire (40) 20-amp circuits to single dual NEMA 6-15R recepticas for the initial (80) units, and use C13 -> 6-15P power plugs. Since each socket is rated at 15amps, and I'll be drawing about 6.23 amp, I believe I'll be fine current wise on the receptical, the 20 amp wire, and the resulting 62% loaded 20amp breaker.

The building is split into 2 equal halves, each designed to hold up to (100) sources. I will be wiring one transformer to each side, once I grow enough to justify the 2nd one.

The rest of the path back to the transformers is a bit less definitive. Please correct any statements below that are inaccurate!

I'm thinking of installing (4) Homeline 225amp main lug 30-space panels. Since each 220V breaker will consume (2) spaces, this will allow for the targetted (50) 20 amp 220V circuits with room left for trivial loads like LED lighting. (Math check: 4*30 space, 2 spaces/breaker = 60 potential double breakers... yeah, good.) If I place a max of (13) load circuits in each panel, at 6.23*2 amps each, I'd have a total panel load of 162 amps for a 72% panel breaker load on (2) panels, and a 66% load on the other (2). That works for the individual panels. Total load back on the system would be 623 amps continuous, for a 78% load on a 800 amp main breaker.

Side note: For a long time, I have always used QO panels and breakers, even in static setup situations. Alas, those breakers are almost twice as expensive as Homelites, and I won't be changing the wiring during the life of this project, so I'm having a tough time justifing QO. Please feel free to convince me otherwise.

So: so far we have (80) computers connected to (4) panels, thirsty for juice from one of the 167kw transformers a dozen or two feet away. This is the point where my experience fails me (or if you prefer: I'm exposed to a growth opportunity!). I see that Schneider has an I-line series of panels, some conveniently rated at 800 amps which would mate to the load from my (4) 225 amp panels.

Basically I need to get the power from the meter near the transformer, into a distribution panel, and out to my (4) breaker panels. Without really understanding the I-line series, I presume I can bring the power into one of them, install (4) 225 amp breakers, and just run power to each of the main lug breaker panels? Beyond that I'm lost. NEMA class 1 is fine for this project. Looking at the Schneider and Graybar sites (Graybar to get a feeling for actual vs. msrp pricing) I see I-Line enclosures (the metal box), pricy I-Line interiors (presumably "the guts"), something called a "solid neutral", and last but not least, a seperately priced door (really? People build these without doors???).

Suffice it to say that I always do my best to follow national codes, but the area I live in enforces none (really... not a single government person cared when I built our home beyond the tax collector). As with most projects, money is somewhat tight so looking for ways to save any, usually at the expense of my time and effort.

Any insight and guidance , both in general and specifically around the I-Line portions, would be greatly appreciated. Trying to learn here, please do not simply say "Go hire a licensed electrician". I may end up doing that anyhow, but if I do, I want to be able to intelligently question their proposals.
 
Kevin Carpenter said:
Hi all -

I'm new to the forum. I have decades of around-the-house&farm experience with wiring, but to date, I've maxed out with 200 amp services.

I'm about to put up a building that will eventually consume about 300kw of singe phase power 220V. The initial phase will be half of that. My local rural utility is helpful and confirmed they can (barely) support the 300kw. They have offered me (2) 167kw transformers, at their cost, including the underground power runs. All of my major internal needs will be 220V based, with an initial load from (80) 1372w computers (e.g. continuous load, no major inrush issues beyond what the power supplies will consume when powered up). That will eventually grow to (200) sources, IF my business model holds up to reality. Since the power supplies require 220v and a C13 plug, I intend to wire (40) 20-amp circuits to single dual NEMA 6-15R recepticas for the initial (80) units, and use C13 -> 6-15P power plugs. Since each socket is rated at 15amps, and I'll be drawing about 6.23 amp, I believe I'll be fine current wise on the receptical, the 20 amp wire, and the resulting 62% loaded 20amp breaker.

The building is split into 2 equal halves, each designed to hold up to (100) sources. I will be wiring one transformer to each side, once I grow enough to justify the 2nd one.

The rest of the path back to the transformers is a bit less definitive. Please correct any statements below that are inaccurate!

I'm thinking of installing (4) Homeline 225amp main lug 30-space panels. Since each 220V breaker will consume (2) spaces, this will allow for the targetted (50) 20 amp 220V circuits with room left for trivial loads like LED lighting. (Math check: 4*30 space, 2 spaces/breaker = 60 potential double breakers... yeah, good.) If I place a max of (13) load circuits in each panel, at 6.23*2 amps each, I'd have a total panel load of 162 amps for a 72% panel breaker load on (2) panels, and a 66% load on the other (2). That works for the individual panels. Total load back on the system would be 623 amps continuous, for a 78% load on a 800 amp main breaker.

Side note: For a long time, I have always used QO panels and breakers, even in static setup situations. Alas, those breakers are almost twice as expensive as Homelites, and I won't be changing the wiring during the life of this project, so I'm having a tough time justifing QO. Please feel free to convince me otherwise.

So: so far we have (80) computers connected to (4) panels, thirsty for juice from one of the 167kw transformers a dozen or two feet away. This is the point where my experience fails me (or if you prefer: I'm exposed to a growth opportunity!). I see that Schneider has an I-line series of panels, some conveniently rated at 800 amps which would mate to the load from my (4) 225 amp panels.

Basically I need to get the power from the meter near the transformer, into a distribution panel, and out to my (4) breaker panels. Without really understanding the I-line series, I presume I can bring the power into one of them, install (4) 225 amp breakers, and just run power to each of the main lug breaker panels? Beyond that I'm lost. NEMA class 1 is fine for this project. Looking at the Schneider and Graybar sites (Graybar to get a feeling for actual vs. msrp pricing) I see I-Line enclosures (the metal box), pricy I-Line interiors (presumably "the guts"), something called a "solid neutral", and last but not least, a seperately priced door (really? People build these without doors???).

Suffice it to say that I always do my best to follow national codes, but the area I live in enforces none (really... not a single government person cared when I built our home beyond the tax collector). As with most projects, money is somewhat tight so looking for ways to save any, usually at the expense of my time and effort.

Any insight and guidance , both in general and specifically around the I-Line portions, would be greatly appreciated. Trying to learn here, please do not simply say "Go hire a licensed electrician". I may end up doing that anyhow, but if I do, I want to be able to intelligently question their proposals.
Click to expand...

My guess is looking at individual component pricing for the I line panel will yield a much higher overall price then putting together a complete order with all the components needed - and include all other Square D items you may need, such as the Homeline panels and breakers and let them give you a quote for the whole shebang. I can buy an I line full of breakers for less then I can buy just 2 or 3 breakers to add into one in most cases, they want to sell these by the job or make big $$ off the random pieces.

They don't come with a cover because there are multiple options available for covers, so you order the one you desire.
 
kwired said:
My guess is looking at individual component pricing for the I line panel will yield a much higher overall price then putting together a complete order with all the components needed - and include all other Square D items you may need, such as the Homeline panels and breakers and let them give you a quote for the whole shebang. I can buy an I line full of breakers for less then I can buy just 2 or 3 breakers to add into one in most cases, they want to sell these by the job or make big $$ off the random pieces.

They don't come with a cover because there are multiple options available for covers, so you order the one you desire.
Click to expand...

Makes perfect sense. Had planned on buying all 100 breakers at once.

Any suggested vendors to get quotes from, or even more importantly, NOT to use (Grainger is on the NOT list...)

Thanks.
 
For situations where you have 6 or fewer panels, using a MLO service rated main distribution panel is typically the most cost effective way to go because you dont have to buy that big main breaker. I-Line is a good choice. Just talk to a supply house and get a quote for the whole package with all 4 breakers, it wont be that much. Keep in mind that if you do build the other half, your new panel will need to be grouped with the existing one (unless you can call it another building or occupancy), and you cant have more than 6 mains. You will have 4 with the existing, so unless you need only 2 distribution breakers in the new panel, you would get a main breaker panel for the second one which would give you 5 service disconnects total and you could have as many breakers as you wnat below it.
 
electrofelon said:
For situations where you have 6 or fewer panels, using a MLO service rated main distribution panel is typically the most cost effective way to go because you dont have to buy that big main breaker. I-Line is a good choice. Just talk to a supply house and get a quote for the whole package with all 4 breakers, it wont be that much. Keep in mind that if you do build the other half, your new panel will need to be grouped with the existing one (unless you can call it another building or occupancy), and you cant have more than 6 mains. You will have 4 with the existing, so unless you need only 2 distribution breakers in the new panel, you would get a main breaker panel for the second one which would give you 5 service disconnects total and you could have as many breakers as you wnat below it.
Click to expand...

Thank you. The good news, I suspect, is that the two halves of the building are electrically 100% independent and will be fed from two separate transformers. Basically what I do for 100 computers will simply be mirrored on the other half of the building. If there is some code thing about having 2 main distribution panels in one building... well... no codes out here. Can't see why it would matter though, but I'm likely not educated enough yet.
 
Kevin Carpenter said:
If there is some code thing about having 2 main distribution panels in one building... well... no codes out here. Can't see why it would matter though, but I'm likely not educated enough yet.
Click to expand...

The general rule is that service disconnects must be grouped in one location. Doesnt the utility require an inspection or underwriters approval before they will energize a service?
 
ptonsparky said:
I would be concerned with the fault current available from your transformer exceeding that of the Homeline breakers. Have you had that calculation done yet?
Click to expand...

Yeah I was had some concern about that too. May need main breakers in the sub-panels which will get him up to 22K but that might not be enough. He could be around 35K at the transformer secondary and not sure what it would be at the loadcenters.. Not sure if the MB in a homeline panel series rates with I-line or not.
 
electrofelon said:
Yeah I was had some concern about that too. May need main breakers in the sub-panels which will get him up to 22K but that might not be enough. He could be around 35K at the transformer secondary and not sure what it would be at the loadcenters.. Not sure if the MB in a homeline panel series rates with I-line or not.
Click to expand...

How close are the transformers to the service equipment?
 
electrofelon said:
The general rule is that service disconnects must be grouped in one location. Doesnt the utility require an inspection or underwriters approval before they will energize a service?
Click to expand...

The last time I hooked up a building I called them and stated I was ready to have the service connected to the meter. They responded "So pull the meter and connect it...". Which I was comfortable doing and did. About 4 months later they came out and put a seal on the meter box. Such is life in Rural America.
 
mwm1752 said:
How close are the transformers to the service equipment?
Click to expand...

The transformers will be placed on pads right outside of the building. Each will be connected to an I-Line, from which I will distribute to (4) main lug 225 amp panels (at 81% load on (2) of the (4) panels if I use 200 amp main breaker panels (combined across all four panels though I'm below the 80% mark on the I-Line 800 amp breaker)).

Total wire distance from each transformer to each I-Line will likely be less than 20 feet, perhaps 15 feet presuming I bottom feed the I-Lines.
 
You will need to get the impedance off the transformers to calculate the fault current. Alternatively you could ask for the fault current at the secondary from the utility, but that will often result in a much higher than actual value. Then you need to coordinate the AIC of all your equipment to that value. If you can't get what you need from those loadcenters, you will need to get full panelboards.
 
Kevin Carpenter said:
Makes perfect sense. Had planned on buying all 100 breakers at once.

Any suggested vendors to get quotes from, or even more importantly, NOT to use (Grainger is on the NOT list...)

Thanks.
Click to expand...
An electric supply house that is an authorized Square D distributor is where you would have to order from, Graybar may be one of those, I use a local supplier, when they give me such quotes they submit them to Square D and Square D tells them how much they will sell the package for, of course I never know what the distributor makes on it but Square D is who sets my price, not the distributor.
 
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