DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   Electrical (
-   -   100A Fuse Panel Replacement (

Charlie1101 07-22-2009 03:54 PM

100A Fuse Panel Replacement
As part of an addition project, I need to replace a 100A main panel and a 60A sub panel. My plan is as follows:

1. Gut 60A fuse panel and use as junction box to run circuits back to main panel. This sub panel is in a cabinet and violating the 30" rule.

2. Place new 100A breaker panel next to current 100A fuse panel. Run #4 Cu, #6 ground to new panel. I'm thinking to keep the main fuse in the old box, gut the rest and use the rest as a junction box. I would have to use junction boxes to make the branch connections anyway so this eases that and also eliminates the need to have the meter pulled.

I plan to install a ground rod to the old panel to accompany the existing water pipe connection. A permit will be pulled and inspections performed. I know about isolating the ground and neutral in the new panel.

My questions are:

A) Is this a proper use of the old boxes? I can easily fix the door on the 60A to require a screwdriver to open it. The old 100A panel is more of a challenge. I need to leave the fuse accessible but cover the junctions. A piece of sheet metal screwed to the cover could accomplish this.

B) Is the wire sizing above correct for the 100A connection? What size neutral?

Anything else I'm missing?

Thanks for the help.

J. V. 07-23-2009 11:41 AM

You can use blanks to cover the open slots where the breakers resided. Yes, you can use the old panels as j-boxes. But do not modify the cover or panel enclosure in any way. Just cover the slots with UL listed blanks that will fit your panel. Also mark the outside of the converted panel enclosures.

For the 100 amp panel you need #3 Cu plus a #8 ground.
For the 60 amp panel you need #6 Cu plus a # 8 ground.

4 wires for both H-H-N-G.

Charlie1101 07-24-2009 12:49 PM

Thanks. I hadn't thought of the blanks.

I had this idea while at work. Well, I forgot about the cast iron drain pipe just to the right of the panel so nevermind.

Looks like I am stuck with replacing the panel. The concerns I have with this are having the power cut off, replacing panel, getting it inspected and getting the power back on within a day.

I think it is possible but I could see it dragging out an extra day. Also, I'm not sure if I will be able to use the existing service wires. I don't know if they will reach the lugs on the new panel. Needing to run new wiring from meter to the panel would be a pain.
Is there a compelling reason to replace these anyway? It looks like they are #2 Al.

J. V. 07-25-2009 11:37 AM

Build your new service panel (meter main) before you remove the existing one. Temporarily power the new panel with the existing service conductors. Have everything ready for the POCO to plug in the new meter. Heres how I do it if I need more than one day.

1) Pull meter (Professional only) or switch OFF disconnect. (Much safer)
2) Disconnect all wires in panel (mark them)
3) Pull out old panel.
4) Install new panel and connect the existing service conductors to a 2 pole breaker (100 amp) is ideal.
5 Install new breakers.
6) Connect all circuits

Now you have an operational panel, but you still need to upgrade your service conductors.

1) Install new meter main as per POCO regulations.
2) Run service entrance conductors to the main breaker or lugs in new panel. (you should do this while you are doing step #6 above.
3) Connect new service conductors in panel.
4) Turn off main breaker for the new service and lock it if possible.

Now, you must be present for the power up by the POCO. Remove old service conductors from breaker after POCO pulls the old meter. Then you can give them the okay to plug in the new meter to the new service.

This is how I did mine at home. If I were doing this for you I would bring a generator. This may not be a DIY project. Unless you are totally comfortable with the work, please get help. Hire someone that is qualified.

Charlie1101 07-25-2009 02:22 PM

I'm comfortable with the work. I am planning to rent a generator for lights and maybe to temporarily run the refrigerator.

I am a little confused by your some of your reply. I have a 100A fuse panel and am replacing it with a 100A breaker panel.

I don't think I need to upgrade the service conductors and meter. Am I missing something? If this is needed, then I may change my mind about doing this.

Otherwise, I'm not sure if I have enough length on the existing service conductors to reach a new panel. Worst case I think I'll have to run new service conductors from the existing meter to the new panel.

thanks for the reply.

All times are GMT -5. The time now is 12:22 AM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

Search Engine Friendly URLs by vBSEO 3.6.1