Large gauge taps

[johnfluevogs]

Bigger picture for those interested...

-- the main panel is located on one side of the garage, and I wanted to locate the sub-panel on the other side of the garage. The garage is 30' wide, therefore, the feeder run will be approximately 35-40'. (still unclear if this qualifies under the tap rule)

-- the sub-panel will be a main lug panel relying on overcurrent protection of the main panel. (I believe this is allowed since the sub panel will be in the same building, and same room (garage).)

-- the sub-panel will be surface mounted to make running surface mount EMT easy. The feeder from the main (eg SER) will be run in the wall cavity. What is the best way to bring the feeder (eg SER) into the sub-panel? Through the back? Via a "deep" jbox which would function as an elbow?

Thanks.

 

[electrofelon]

What the disconnect feed currently? If you stick with 200 amp conductors (including next size up rule) to the new panel that it is not a tap. If it is less than 200, then you would need to comply with one of the tap rules.

 

[electrofelon]

I would just run the SER surface mounted with some straps and into the top of the panel

 

[johnfluevogs]

What the disconnect feed currently? If you stick with 200 amp conductors (including next size up rule) to the new panel that it is not a tap. If it is less than 200, then you would need to comply with one of the tap rules.

Main panel in garage is 200 amp disconnect that feeds a 200 amp sub-panel in the basement. I planned on using suitable "200" conductors.

Thanks!

 

[johnfluevogs]

I would just run the SER surface mounted with some straps and into the top of the panel

That works for me, but the main panel is flush mount, so how do I route SER from surface of drywall to the main panel...

Also, I figured surface mount SER in a garage would need sole protection.

 

[electrofelon]

That works for me, but the main panel is flush mount, so how do I route SER from surface of drywall to the main panel...

Also, I figured surface mount SER in a garage would need sole protection.

I would drill a hole just below the top plate, then cut in one of these access panels for access and bring it into the top of the panel.

Everbilt 14 in. x 14 in. Adjustable Spring Loaded Plastic Access Panel APS14 - The Home Depot

Keep unsightly connectors hidden with this spring fit access panel. Safely stow plumbing, spa pumps, wires and cables for residential and commercial applications. Constructed with durable white polystyrene,

www.homedepot.com

What are you doing in this garage, practicing hatchet throwing? Unless you're doing something like that I don't really see what is going to happen to the SER.

 

[kwired]

Main panel in garage is 200 amp disconnect that feeds a 200 amp sub-panel in the basement. I planned on using suitable "200" conductors.

Thanks!

Use 200 amp conductors and a 200 amp panel, doesn't need to have a main, and it is not a feeder tap and no distance limitations.

That works for me, but the main panel is flush mount, so how do I route SER from surface of drywall to the main panel...

Also, I figured surface mount SER in a garage would need sole protection.

I'd likely use a 6 or even 8 inch deep junction box, cut out wall and intercept the existing 200 amp feeder and mount so that part of depth is in the wall and part outside the wall so you can surface mount your new portion to new garage panel. Might also be easier than splicing in the existing disconnect as there likely not much extra room in there to do this.

 

[johnfluevogs]

I would drill a hole just below the top plate, then cut in one of these access panels for access and bring it into the top of the panel.

Everbilt 14 in. x 14 in. Adjustable Spring Loaded Plastic Access Panel APS14 - The Home Depot

Keep unsightly connectors hidden with this spring fit access panel. Safely stow plumbing, spa pumps, wires and cables for residential and commercial applications. Constructed with durable white polystyrene,

www.homedepot.com

What are you doing in this garage, practicing hatchet throwing? Unless you're doing something like that I don't really see what is going to happen to the SER.

Hatchet throwing...touché.

 

[johnfluevogs]

Use 200 amp conductors and a 200 amp panel, doesn't need to have a main, and it is not a feeder tap and no distance limitations.

I'd likely use a 6 or even 8 inch deep junction box, cut out wall and intercept the existing 200 amp feeder and mount so that part of depth is in the wall and part outside the wall so you can surface mount your new portion to new garage panel. Might also be easier than splicing in the existing disconnect as there likely not much extra room in there to do this.

I had not thought about "intercepting" the existing 200 amp feeder - great idea! The existing feeder runs vertically into the attic above the garage, perhaps I should just slice in the attic can intercept and splice in the attic (which is accessible by ladder)? OR, would it be preferable to have the junction box in the wall above the main disconnect and thus "accessible" to all?

 

[kwired]

I had not thought about "intercepting" the existing 200 amp feeder - great idea! The existing feeder runs vertically into the attic above the garage, perhaps I should just slice in the attic can intercept and splice in the attic (which is accessible by ladder)? OR, would it be preferable to have the junction box in the wall above the main disconnect and thus "accessible" to all?

In attic is easier yet, most cases, and a junction/splice box only needs to be accessible vs readily accessible.

 

[johnfluevogs]

@kwired thank you for the candid direction!

 

[johnfluevogs]

@kwired same project - different question: what are your thoughts on are using a 50a exterior receptacle box (eg RV box) in place of an LB where 2/0, 2/0, 2/0, 1 THHN (or equivalent conductors) enter a building in conduit. Said differently, do you think an RV Box would have enough room to double as an LB for 4 conductors (2/0, 2/0, 2/0, 1).

314.28 should control whether or not the RV Box will have enough room....right?

I be crystal clear, the 2/0 condcutors will only pass through the RV Box. The receptacle will be powered directly from a breaker in a panel. I am only contemplating sharing the box space to avoid unnecessary conduit and boxes on the outside of the garage

 

[kwired]

@kwired same project - different question: what are your thoughts on are using a 50a exterior receptacle box (eg RV box) in place of an LB where 2/0, 2/0, 2/0, 1 THHN (or equivalent conductors) enter a building in conduit. Said differently, do you think an RV Box would have enough room to double as an LB for 4 conductors (2/0, 2/0, 2/0, 1).

314.28 should control whether or not the RV Box will have enough room....right?

I be crystal clear, the 2/0 condcutors will only pass through the RV Box. The receptacle will be powered directly from a breaker in a panel. I am only contemplating sharing the box space to avoid unnecessary conduit and boxes on the outside of the garage

need 6 times raceway size to opposite wall. Did not verify but your conductor combination likely will need 2 inch raceway so box would need to be at least 12 inches tall. If 1.5 inch raceway will contain these conductors then box must be at least 9 inches tall.
Conduit bodies need to follow this sizing as well, unless they are marked with maximum conductors and number of them they have been tested for.

Most RV receptacle boxes I've seen won't be this large, particularly if they only have a single outlet and no other accessories in them.

 

[johnfluevogs]

need 6 times raceway size to opposite wall. Did not verify but your conductor combination likely will need 2 inch raceway so box would need to be at least 12 inches tall. If 1.5 inch raceway will contain these conductors then box must be at least 9 inches tall.
Conduit bodies need to follow this sizing as well, unless they are marked with maximum conductors and number of them they have been tested for.

Most RV receptacle boxes I've seen won't be this large, particularly if they only have a single outlet and no other accessories in them.

I too was skeptical that an RV Box would not have the space....