Service Cable -What should I use

I am installing the electric in my new house (in Ohio) and need some advice.

The main service is 320/400 amps (single phase), per power company based on Sq ft, and geothermal heating / toaster back up…

I have two 200 apm fused panels next to the meter box which I am using as the main panels, so that I can locate my “sub” panels through out the house (one on each floor).

By doing this, I understand I will need a HHNG set up for the subs back to the main.

What type of wire do I need to use? Can I run THHN 2/0 STR cu, individually without a conduit (through floor I-joists)?

If not, what kind of cable will work? :neutral:

PS, I understand Ohio is not following the new 2008 NEC.

I’m going to have an electrician check everything out, but I’m just trying to do as much of it as is possible.

If you are trying to run 3 phase and need to ask a group of Home Inspectors ,you bettor call a real Electrician.

It Sounds like you are feeding 2-200amp subpanels if so you should be using SER cable which carries an isolated neutral and separate ground for each panel and at the sub panel you need to make sure the Neutral is isolated from the panel and ground (do not install the bonding jumper from the panel can to the neutral bar or remove it already installed), the neutrals should be only landed on the neutral bar and grounds only to the ground bar. If you are needing to ask these kinds of questions try to find a retired electrician to help with the job and to guide you. eletrical installation is very critical to a safe enviroment not a good place for a doit yourselfer to get thier feet wet

Robert, I don’t see where he said anything about 3-phase, but after this question:

…I am also convinced he would be MUCH safer having a pro do this work.

It always makes me wonder why folks feel the need to “save money” on one of the most critical systems in the house by doing things themselves. Especially a 320/400 service.


What is the current rating of the sub panels you are feeding from the 200 amp fused main panels? How many sub panels are there?

Damn you caught me
I read fast as voltage. oppps

Original opinion stands though.

lol…anyway whom ever asked…just use SER Cable and you are fine. However, I do agree…call an electrician to assist you here before you have problems later.

If you have 200A remote distribution panels on different floors simply use 4/0 AL SER to each panel with the proper SER connector at each panel and dont forget to pick up that extra busbar[s] ( unless one is provided already in the panel setup )