4awg big enough from pole to house? 400a panel

[roger]

He didn't say it was a 400A service. He said it was a 400A panel, and a 300A load.

Service conductors do not have to have the same rating as the service entrance equipment, under the NEC.

Also, 310.15(B)(7) gives him an extra 63 amps on that 350, if it's copper.

He said it was from the "service point" (his electrician said connection point) to the panel which indicates it is a service and by saying 400 A it would seem he is implying a 400 A service.

If it isn't a 400 A service the OP needs to tell us what it is, in any case the POCO conductors don't fall under the NEC.

Roger

 

[romex jockey]

He said it was from the "service point" (his electrician said connection point) to the panel which indicates it is a service and by saying 400 A it would seem he is implying a 400 A service.

If it isn't a 400 A service the OP needs to tell us what it is, in any case the POCO conductors don't fall under the NEC.

Roger

Understood , so all those goofy 310 'free air 2000V' charts apply to the consumer side, i'm just at a loss as to where we'd apply them

~RJ~

 

[roger]

Understood , so all those goofy 310 'free air 2000V' charts apply to the consumer side, i'm just at a loss as to where we'd apply them

~RJ~

When I have had to use them (only a couple) it was in industrial facilities such as paper mills.

Roger

 

[romex jockey]

I wonder about them Roger, check out Table 310.15(B)(19) (formerly Table 310.19)

It claims we can do #4 cu @ 220A> 392°F

i'm at a loss as to what kind of equipment, connectors or whatever makes onto that would do?


~RJ~

 

[mivey]

Not trying to be funny or rude, but is there not a RIGHT or WRONG here? Pretty much everything else in electrical work has specific guidelines and sizing requirements but this is the one situation that is a “just do what works till it catches fire” kinda thing?

again, I honestly am not trying to be funny or sarcastic....just a lil confused.


Also, I’d like to make sure I’ll be getting what I’m paying for. I’ve got some hi powered TIG and MIG machines that I’d rather not short on incoming power.

Thanjs again for all the replies!

What you paid for? If your load is not a typical residential load then it does not fit the parameters used for the residential rate. Proper residential rate design covers costs for service to typical residential loads. It will not usually recover costs well for atypical loads and those costs would get subsidized by other customers.

It may be that you should be moved to a commercial demand rate which will normally be much higher and covers costs associated with larger services with abnormal load factors similar to what you seem to be describing.

 

[electrofelon]

Understood , so all those goofy 310 'free air 2000V' charts apply to the consumer side, i'm just at a loss as to where we'd apply them

~RJ~

When running triplex or quad between structures.

 

[Onlyincali]

What you paid for?.

Yes. Meaning, I just paid about 8 grand for a panel upgrade to go from 100 amps to 400 amps and I did it so I can run high powered shop equipment and welders while also adding a spa and an electric tankless water heater/2 electric driers in the house. I just want to make sure I will be provided the power without issue in the future.

They haven’t reconnected yet and I figured now would be the time to address it. I thought there would be a simple “yes” or “hell no” to my question of whether or not the two 4gauge solid copper wires that run 80ft through the air (from pole to house connect) would do this but it’s becoming clear as mud.

Thank you you guys for the replies! Greatly appreciated. So far, it sounds like no one really knows the answer other than “it might work, it might not. You might get house damage if they are insufficiently sized, you might not” and “it’ll probably work but they are probably undersized”. Haha. Sounds like power companies play by no written rules.
. I’m all ears to new answers!! Thanks!

 

[mbrooke]

Yes. Meaning, I just paid about 8 grand for a panel upgrade to go from 100 amps to 400 amps and I did it so I can run high powered shop equipment and welders while also adding a spa and an electric tankless water heater/2 electric driers in the house. I just want to make sure I will be provided the power without issue in the future.

They haven’t reconnected yet and I figured now would be the time to address it. I thought there would be a simple “yes” or “hell no” to my question of whether or not the two 4gauge solid copper wires that run 80ft through the air (from pole to house connect) would do this but it’s becoming clear as mud.

Thank you you guys for the replies! Greatly appreciated. So far, it sounds like no one really knows the answer other than “it might work, it might not. You might get house damage if they are insufficiently sized, you might not” and “it’ll probably work but they are probably undersized”. Haha. Sounds like power companies play by no written rules.
. I’m all ears to new answers!! Thanks!

Ok- electric tankless water heater- thats code for call and let the POCO know. I know that around here electric tankless water heaters change things. Around me a home got a trafo upsize from 25 to 50kva because of it.

 

[guschash]

G oing through the same thing today. HO wants to upgrade from 200amp panel to a 400 amp panel. He is building a barn and wants 200 amps in the barn. He has one barn with 100 amps in it. Power company gave him a huge meter/disconnect. I'm going to double lugs wires on load side. There is 4/0 coming from pole. I question this and HO said Poco said he was fine. Called inspector and he said no way. If I use copper at 90 deg. 4/0 is good 260 amps., al. only for 205 amps. I'm going to talk to HO and on maybe changing 200 amp CB to 150 amp and then 100 amp to new barn.

 

[electrofelon]

Yes. Meaning, I just paid about 8 grand for a panel upgrade to go from 100 amps to 400 amps and I did it so I can run high powered shop equipment and welders while also adding a spa and an electric tankless water heater/2 electric driers in the house. I just want to make sure I will be provided the power without issue in the future.

They haven’t reconnected yet and I figured now would be the time to address it. I thought there would be a simple “yes” or “hell no” to my question of whether or not the two 4gauge solid copper wires that run 80ft through the air (from pole to house connect) would do this but it’s becoming clear as mud.

Thank you you guys for the replies! Greatly appreciated. So far, it sounds like no one really knows the answer other than “it might work, it might not. You might get house damage if they are insufficiently sized, you might not” and “it’ll probably work but they are probably undersized”. Haha. Sounds like power companies play by no written rules.
. I’m all ears to new answers!! Thanks!

Around here, whenever a service upgrade is done the poco asks if the loads have changed. Not sure if that was done or asked for in your case. As someone else said express your concerns to your utility rep. Probably it will be fine, there will be lots of diversity.

 

[romex jockey]

Ok- electric tankless water heater- thats code for call and let the POCO know. I know that around here electric tankless water heaters change things. Around me a home got a trafo upsize from 25 to 50kva because of it.

Yup.

dropped a 200A commercial service into a 9 unit place for a huge tankless

poco changed out for a 50K trafo

the unit never gets a break (despite holding tanks) , the 'lectric bill went china

but boy do I feel green! ~RJ~

 

[LarryFine]

So far, it sounds like no one really knows the answer other than “it might work, it might not. You might get house damage if they are insufficiently sized, you might not” and “it’ll probably work but they are probably undersized”. Haha. Sounds like power companies play by no written rules.
. I’m all ears to new answers!! Thanks!

I suggest doing an old-fashion load calc.

 

[mbrooke]

Yup.

dropped a 200A commercial service into a 9 unit place for a huge tankless

poco changed out for a 50K trafo

the unit never gets a break (despite holding tanks) , the 'lectric bill went china

but boy do I feel green! ~RJ~

That usually how it works- when you have endless hot water, people tend to use more of it. I've known people go tankless and their bill be it gas or electric went up 2 or even 3 fold fold.

 

[roger]

I suggest doing an old-fashion load calc.

:thumbsup:

Heck, I'm still waiting for an answer to how the EC came up with his wire size?

Roger

 

[kwired]

Yes. Meaning, I just paid about 8 grand for a panel upgrade to go from 100 amps to 400 amps and I did it so I can run high powered shop equipment and welders while also adding a spa and an electric tankless water heater/2 electric driers in the house. I just want to make sure I will be provided the power without issue in the future.

They haven’t reconnected yet and I figured now would be the time to address it. I thought there would be a simple “yes” or “hell no” to my question of whether or not the two 4gauge solid copper wires that run 80ft through the air (from pole to house connect) would do this but it’s becoming clear as mud.

Thank you you guys for the replies! Greatly appreciated. So far, it sounds like no one really knows the answer other than “it might work, it might not. You might get house damage if they are insufficiently sized, you might not” and “it’ll probably work but they are probably undersized”. Haha. Sounds like power companies play by no written rules.
. I’m all ears to new answers!! Thanks!

As others have asked, was POCO informed the load has changed?

They can still supply this with whatever they want but if they still want to supply with what was there, sure seems there is a good chance of voltage drop issues. They likely are supposed to supply you within 10% of nominal voltage.

Possible they maybe even need to upgrade transformer with what you have added to be able to deliver proper voltage at the load levels you might expect at times.

 

[mivey]

Yes. Meaning, I just paid about 8 grand for a panel upgrade to go from 100 amps to 400 amps and I did it so I can run high powered shop equipment and welders while also adding a spa and an electric tankless water heater/2 electric driers in the house. I just want to make sure I will be provided the power without issue in the future.

They haven’t reconnected yet and I figured now would be the time to address it. I thought there would be a simple “yes” or “hell no” to my question of whether or not the two 4gauge solid copper wires that run 80ft through the air (from pole to house connect) would do this but it’s becoming clear as mud.

Thank you you guys for the replies! Greatly appreciated. So far, it sounds like no one really knows the answer other than “it might work, it might not. You might get house damage if they are insufficiently sized, you might not” and “it’ll probably work but they are probably undersized”. Haha. Sounds like power companies play by no written rules.
. I’m all ears to new answers!! Thanks!

The #4 CU would not be big enough if you have a big enough instant water heater. #2 CU would be marginal and probably #1/0 or 2/0 CU would be more in the range of what you would need.

CU is probably out anyway so you are looking at #1/0 AL marginal with #3/0 or #4/0 AL more like what you need.

Larger transformer probably as well: 37.5 to 50 kVA.

 

[LarryFine]

Earlier this year I upgraded a 200a service to 400a (320) to accommodate a tankless water heater that required four 40a circuits. I asked the POCO about the underground conductors being up-sized.

"Nope."

In fact, I received the same response when inquiring about a 200-to-600a upgrade for a bitcoin-farming installation.

 

[electrofelon]

Earlier this year I upgraded a 200a service to 400a (320) to accommodate a tankless water heater that required four 40a circuits. I asked the POCO about the underground conductors being up-sized.

"Nope."

In fact, I received the same response when inquiring about a 200-to-600a upgrade for a bitcoin-farming installation.

Yeah you never know what you will get. I added a 5th meter for a 5th apartment on an existing service. POCO did upgrade the drop but not the tranny. They say if a utility doesnt burn up a few transformers and service drops now and then, they are sizing them too big

 

[mivey]

Yeah you never know what you will get. I added a 5th meter for a 5th apartment on an existing service. POCO did upgrade the drop but not the tranny. They say if a utility doesnt burn up a few transformers and service drops now and then, they are sizing them too big

That is a fair enough statement as strange as it seems. If you assume that they put in an adequately sized transformer and service most of the time and might miss some every now and then, the losses associated with oversizing everything would far exceed the cost of the occasional replacement.

Most of the time however I see utilities oversizing transformers unless they have a good sizing program in place with good data tables.

 

[Onlyincali]

The #4 CU would not be big enough if you have a big enough instant water heater. #2 CU would be marginal and probably #1/0 or 2/0 CU would be more in the range of what you would need.

CU is probably out anyway so you are looking at #1/0 AL marginal with #3/0 or #4/0 AL more like what you need.

Larger transformer probably as well: 37.5 to 50 kVA.

Thank you very much!!!!!!!