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View Full Version : Liquidtight Flexible Metal Conduit (LFMC) to connect subpanels to service entrance


RTSlater
Feb 4, 2011, 12:48 PM
Can I use Liquidtight Flexible Metal Conduit (LFMC) to connect 5 or 6 subpanels to the service entrance panel in a domestic dwelling?
I know it is expensive but I have a lot of it from a commercial overstock sale, so price is not a consideration. Ease of installing the conduit runs is.
David

donf
Feb 4, 2011, 02:20 PM
Is this for a residence?

Yes, you can do this, however, why would you is none of the cable runs require protection. 5 or 6 subpanels makes me immediately question the adequacy of your main service.

Do you have enough amperage to safely feed all of these subpanels.

RTSlater
Feb 7, 2011, 10:34 AM
No, but a 200 Amp Main Panel is part of the upgrade. I have an electronics workshop on the top floor, a woodworking shop in the basement and a metal shop in a detached garage. I want the subpanels near their loads: less walking to reset CB's
David

donf
Feb 7, 2011, 12:41 PM
Okay.

You have 200 amp service for the entire residence, correct?

From the Main Service Panel you have three feeders to three sub panels. Panel "B" upstairs electronics workshop, Panel "C" to downstairs woodshop and Panel "D" to a remote structure, correct?

Can you please tell us the amperage being sent to each panel.

Also, each subpanel requires a four wire feed. Panels "B" and "C" can use the grounding system provided by the Main Service Panel because they are in the same structure. However, Panel "D" must have it's own grounding system.

None of the sub panels ( "B", "C" or "D") can have Neutral and Grounded together at the panel, they must be isolated.

The only place I would use conduit would be between the Main Service Panel and the remote structure and I would use 2" Schedule 80 or RMC conduit, not the stuff you have.

I would use 2" just in case I would ever need to replace a damaged cable or increase service to sub panel.