200 amp main service, 100 amp subpanel in an attached garage. Need to run power to a pole barn about 130′ away. Easier access/dig to the 100 amp subpanel.
Can I feed a 50 amp subpanel from the 100 amp subpanel?
Expect only to have a lighting circuit and receptacle circuit on the 50 amp subpanel in the pole barn.
Thanks.
Andy
Replies
I wonder about sizing for voltage drop, if that comes into play at all.
Tu stultus es
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
Nothing wrong with cascading panels. In fact in commercial, it is the norm.
It's going to be cheaper to just run the 110 legs.
Huh?
I think what rob is saying is if there is no need for 220 it is cheaper just to run 110 to a small disconnect panel with say two 15 or 20 amp breakers in it. But if you may at some point want a large compressor or welder out there by all means 220.
That is correct.
#10 should easily cover receptacles @ 20A and #12 cover any lighting. I guessed at the size due to the run. Both can be run in PVC conduit so no need for direct burial and I hate the stuff anyway.
"IF" you think you may want more, then a 60 amp sub panel is needed along with larger wire more labor, and additional materials.
While we're talking about sub-panels, I've got a question. My barn has a disconnect fed from my main panel in the house.
This disconnect controls a sub-panel in a finished space in the barn. Can I use this same disconnect to control a second sub-panel I'd like to add to the unfinished part of the barn?
Rich
Any building needs a disconnect "close" to where power enters that building or exterior to the build, but accessible. Whether a primary building where the POCO connects or another building feed off the main one or a farm feed where power comes a central pole and is distributed from that location the most common disconnect is the main breaker in a panel.But for several reasons a separate disconnect is used. Two of the most common is where it is more logical to have the distribution panel near large loads which is not close to the where the power enters or an addition has put that panel in the middle of the structure.If the new sub-panel is in the same structure and feed from the same power source then it does not need a separate disconnect.
.
William the Geezer, the sequel to Billy the Kid - Shoe
So Bill, I'm being a little dense here, please bee patient if you would. The disconnect in the barn is fed from underground from the main panel in the house. It is located very close to where power enters the building. The panel it controls extends probably another 30 feet to the finished space.
Is ok to simply add connections in the disconnect to supply the new panel?
"Is ok to simply add connections in the disconnect to supply the new panel?"Yes..
William the Geezer, the sequel to Billy the Kid - Shoe
Got it, thanks Bill
Andy,
As has been said, it's OK to pass through multiple subpanels. I ran into the same problem feeding power to a building on my property,....easier to tap a 40' run from a 100 amp sub than a 300' run from a 200 amp main panel.
Now, you do know you need a ground rod for that building? I put in two, as I live on a hill, and have had four lighting strikes in 13 years. Now some people on this site will tell you that's overkill, maybe it is, but the last strike killed alot of electronics in neighbors homes, but only fried a surge suppresser in mine.
WSJ
Edited 4/29/2009 11:16 am ET by WorkshopJon
Thanks everyone.
Spoke to elec. inspector. he recommended #6 URD wire in 1 1/4" conduit.
What can you run off of 50amp subpanel? 220 for welder or compressor OK? Project is evolving.
Hi Andy:Your best bet is to get amperage readings off all of your powered devices (or anticipated future powered devices) and then try to figure out what you are likely to be running simultaneously.For example, a heater + compressor + lights + ???.Add up the amperage - if this is more than 80% of your subpanels protection (say, 40 amps on a 50 amp panel) then you're probably pushing too much, and you should upgrade the wires + protection to a larger sub. Better to overbuild a little now then rebuild later.And just to chime in again - you have to have a pair of ground rods for that new panel.-t
"What can you run off of 50amp subpanel? 220 for welder or compressor OK?"
andy,
Funny you ask. I have a Lincoln Electric 220v AC/DC stick welder........ They recommend I think min 8 gauge to feed it, so I open it up, It's wired with 12 (obviously 20- amp max). Shake my head. So yeah, you can run a welder or a fairly large compressor off it.
BTW, It work just fine, and I've never blow a breaker using it.
WSJ
And just for my own question? Would this new subpanel off the existing subpanel also be required to have the ground and neutral busses separated like the first subpanel would?
Sorry for the hijack...just curious.
Short answer, Yes.Long answer, the whole idea is that the neutral and grounds are only bonded together at ONE and ONLY ONE point. That is at the main disconnect which is often the first panel, but not always..
William the Geezer, the sequel to Billy the Kid - Shoe