DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   Electrical (
-   -   Maxed out main panel and sub panel - additional 240v needed (

netcustoms 03-12-2011 10:44 AM

Maxed out main panel and sub panel - additional 240v needed
Kind of new to electrical and I am thinking about purchasing a 240v air compressor but I think I have a big problem. The Main Panel is Maxed out and so is the sub-panel. I am running the sub-panel from the main panel using a 70amp breaker at the main panel. The sub panel currently has two 40amp two-pole 240v circuits in it and i need another one for an air compressor. Can I change the sub-panel to be able to be allow for a 3rd 240v circuit to be run to my additional 40amp disconnect panel outside?

My friend wanted me to tap into the dryer outlet but I don't think that is a good idea since I wouldn't be able to use the dryer and the air compressor at the same time.

Thank you for any input you can provide. I do have a photo of the panel if you would like to see it.

a7ecorsair 03-12-2011 10:48 AM

How many open spaces are available in the sub panel? Will the circuit be in the same building as the sub panel?

netcustoms 03-12-2011 10:53 AM

The sub panel is right next to main panel and it is maxed out too. The 40amp disconnect panel for the air compressor will be in the garage.

J. V. 03-12-2011 11:20 AM

1 Attachment(s)
Check either or both panels and see if they will accept tandem breakers. You could use a couple of these to free up the two spaces you require for the third sub panel.
See the picture of a tandem breaker below. The panel must be listed to allow the use of tandem breakers and where they can be place in the panel board.

However, You make no mention of your service size or how big or small your house is. You don't say if you have gas appliances. You do mention an electric dryer.
If you have less than a 200 amp service, I would be thinking service upgrade.

netcustoms 03-12-2011 11:40 AM

The box doesn't accept the tandem breakers and all but one of the breakers for 120v are slim breakers. 4 of the circuits are already 240v - one for main disconnect, one for subpanel, one for oven and one for hot water heater (i think). This is a large house built in 1901 and has a 200amp service i am pretty sure. The sub panel is only used for a dryer and another subpanel for the pool pump which i would just like to disconnect but i know my wife will want to use it in the next couple of months. My thought is to upgrade the Cutler Hammer sub-panel to one with 8-10 poles and then just add the circuit there.

All times are GMT -5. The time now is 02:45 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