1600 kW service, 3400 Amp conductors;

[herding_cats]

We are working on an application with 480vac service, 1600 kW, or 3400 Amp. This is for the Tesla Semi truck charging system.

I know this is insane. I'm coming here to the group to see what you guys recommend to set up in parallel for conductors.

What would be the most cost-effective method to use parallel conductors?

The conduit is PVC, burial, non-conductive so the single wire transformer rule can be used here. Running similar phases in different 4" PVC tubing is possible here without heat build up.

The runs are short. no more than 30'. There are 2-3 90 degree bends, depending, with a 45 here and there. I thought 500 k mil welding cable might be a good choice for the pull. 8 per phase.

The Tesla semi truck charger situation is a mess. Utility companies are routinely denying the permit for this kind of monster service.

 

[herding_cats]

We are trying to fix the issue with the utility companies.

 

[LarryFine]

Can the load be divided?

 

[zbang]

Why not good ol' THHN/THWN or XHHW? People pull that all the time through multiple bends.
Is aluminum cable acceptable? Might save some $$ but you'll have to price it out.

Forget about something called "welding cable", that's not an NEC cable type. You're probably thinking of "fine-stranded cables" which are mostly listed in article 400 (types W, SC, G), but could also get RHH/RHW in fine strand. Unless there's a real need for flexibility after installation, it'll be better to stick to Article 310 types.

 

[Birken Vogt]

The Tesla semi truck charger situation is a mess. Utility companies are routinely denying the permit for this kind of monster service.

I suspect that what this really means in the end is that the Tesla architecture was conceived by a bunch of tech bros that have no idea what it takes to get a monster service like this approved.

I wonder when they are going to start saying you have to take service at primary 12 kv or whatever or even subtransmission, 40-69 kv, and/or construct such service back to some point miles away, and maintain it.

 

[infinity]

A 3400 amp or even a 4000 amp service is nothing special or out of the ordinary. For a 4000 amp service we would use 10-sets of 600 kcmil THHN or XHHW copper conductors. As zbang suggested forget about any type of welding cable.

 

[herding_cats]

the welding cable was suggested only because of the ease of management. bending, pulling, etc.

 

[infinity]

the welding cable was suggested only because of the ease of management. bending, pulling, etc.

30' of conduit run with a few bends isn't hard to pull with the right equipment for THHN or XHHW. And pulling rubber insulated conductors in any raceway, although more flexible, can still be a nightmare because the insulation tends to bind in the raceway.

 

[don_resqcapt19]

the welding cable was suggested only because of the ease of management. bending, pulling, etc.

If you don't get 100% of the surface covered with wire lube, it will not pull very easy, and unless is is dual marked you can't use it for any NEC application. It is also typically a larger OD than THWN or XHHW and might require a larger raceway. Since it is underground my choice would be XHHW.

 

[electrofelon]

A 3400 amp or even a 4000 amp service is nothing special or out of the ordinary. For a 4000 amp service we would use 10-sets of 600 kcmil THHN or XHHW copper conductors. As zbang suggested forget about any type of welding cable.

Agree, done all the time. It's interesting the responses people get when "Tesla" or "EV charging" gets put in the title.

OP mentioned ISO phase, have you done that on a 4,000 amp service? I'm guessing it is not real practical due to the de-rating.....although 2 sets of 4 may work with 600CU or maybe even 500 depending on the setting of the OCPD.

 

[electrofelon]

.
What would be the most cost-effective method to use parallel conductors?

You're just going to have to run the numbers and see what works best. CU or AL? It goes without saying, but aluminum is cheaper but you will need more or larger raceways. If you go ISO phase, investigate all eight in one pipe or two sets of four for less derating. I don't think eight in one is a very good idea, will not fit in 4-in. (8 500 compact will fit barely, doesn't sound enjoyable however). 500 CU or AL will go in 3".

 

[herding_cats]

My thoughts were to do 8 runs of 4" PVC.

Yes I know the "Tesla" comments get attention. We are seriously working with a charging company to land the right power service to the rectifier and eliminate the battery bank that Tesla wants to put in. When we got this gig I looked at this thinking WTF 1600 kW ? Can you land another sub station out here?!? coming of 12kv primary uses the power of a medium sized hospital...

look up the Baker, CA semi truck install example we were given to design this. The Tesla semi truck infrastructure has serious issues with delivery of a charging infrastructure.

 

[petersonra]

Instead of going underground you might consider using bus bar above ground.

 

[herding_cats]

yes bus bar considered for sure. They wanted a clean look. But you are right something with this level of kW needs to be bus bar driven.

 

[electrofelon]

My thoughts were to do 8 runs of 4" PVC.

It's going to be tough to squeeze it in with only eight pipes. You would need 700 copper with a 3500 ocpd and no derating. Personally I don't like to go that big, such a hassle to work with.

When we got this gig I looked at this thinking WTF 1600 kW ? Can you land another sub station out here?!? coming of 12kv primary uses the power of a medium sized hospital...

4000A from 15kv class distribution is generally not an issue at all, done all the time. Look into New York city's distribution, you're going to be surprised at the voltages they do and do not have

 

[herding_cats]

I know it's common. The problem is that the chargers are supposed to go into truck stops that do not have the infrastructure to handle 1600 kW.

We came up with a holistic solution for them but it's controversial.

 

[herding_cats]

We specified a natural gas turbine based power generation system that is taken from an oil rig platform:

 

[herding_cats]

calculating the gas usage, and the costs of the turbine, it's actually pretty cost effective.

nearly 70% of all electricity currently uses natural gas as the fuel source.

 

[augie47]

There's just something fundamentally wrong with using a natural gas generator to drive a turbine to charge an electric truck

 

[herding_cats]

we don't see any other way to do it. All we are doing is displacing power. Natural gas is where the power comes from regardless.