[DaveMcSF]

I am retired so decided to pour a slab and install a little electric for my "RV" and I ran in to a few situations that I cannot seem to research and get an adequate answer too. So I thought maybe I should ask the "experts" here! A. ----If I decide to go the 6 "Offs" instead of a main breaker at the sub panel--are the 220 outlets with a double breaker counted as one or 2 ?--I intend for the panel to have 1-110V-light duplex receptacle, 1-110 power duplex receptacle 1 -250 30 amp L-6-30R (compresser outlet) and 1-50 amp 120/240V RV service---I think this adds up to 6 breakers---2 double pole and 2 single pole-----SO--do I need a main breaker---or will the 6 strokes off rule make me legal? B. --I intend to go with all GFCI breakers at the sup panel----Is that a good idea?--I am coming off a 200 amp main service panel ---should the 50 amp there for the sub also be a GFCI?

 

[rjniles]

Your count is 4 handle throws, you do not need a main breaker. Do no use a GFCI for the 50 amp in the 200 amp panel. GFCI is not required for the circuits other than 120 volt 15 & 20 amp.

 

[DaveMcSF]

RV parking slab with elect in it

Thank you for that answer--can I ask a few more questions?
1. If I opt to put in a GFI breaker at the L6-30R and the 14-50R---won't that be a "safer" install and then just put in GFI outlets at the 110 outlets?
2. How do I exit the concrete slab vertically as I have installed 1-1/2 inch sched 40 up to surface of slab for the panel and 3/4 sched 40 pvc up to the surface of the slab for the outlets (l6-30R & 14-50R)---I put a threaded coupling at the surface of the concrete thinking I would install rigid threaded conduit from surface of concrete up to the panel and boxes---am I doing this correctly???--Should I use a waterproofing caulk in the threads?
3. At the house I came up out of the trench to +18" above soil with the sched 40 pvc 1-1/2 inch (for my 4,4,4,8 ---4 wire service to the sub panel)---then an accessable pvc "elbow" into the house and a pvc box---Am I ok with pvc here or does it need to convert at some point to metal or waterproof conduit?

 

[sirsparksalot]

Thank you for that answer--can I ask a few more questions?
1. If I opt to put in a GFI breaker at the L6-30R and the 14-50R---won't that be a "safer" install and then just put in GFI outlets at the 110 outlets?
2. How do I exit the concrete slab vertically as I have installed 1-1/2 inch sched 40 up to surface of slab for the panel and 3/4 sched 40 pvc up to the surface of the slab for the outlets (l6-30R & 14-50R)---I put a threaded coupling at the surface of the concrete thinking I would install rigid threaded conduit from surface of concrete up to the panel and boxes---am I doing this correctly???--Should I use a waterproofing caulk in the threads?
3. At the house I came up out of the trench to +18" above soil with the sched 40 pvc 1-1/2 inch (for my 4,4,4,8 ---4 wire service to the sub panel)---then an accessable pvc "elbow" into the house and a pvc box---Am I ok with pvc here or does it need to convert at some point to metal or waterproof conduit?

A GFCI breaker is no more safe than a GFCI receptacle. And why do you need a 30a GFCI breaker for the 6-30 recep.?

Schedule 40 is good underground, but above ground you need schedule 80 if the location is subject to physical damage,

Just to be clear, the rule is that the trench needs to 18" deep, NOT 18" above soil. How deep is the trench.

 

[DaveMcSF]

I thought that a ground fault interrupter--- breaker is safer than not having one--so that if anything down stream is not right then the breaker will shut off---like rain/faulty equipment , anything in the RV going to ground ---etc (this is all outside on a new 32' x 48' slab)--the 2 outlets that I would like to have the gfi's are the 30 amp 250 L6-30 compressor and the 50 amp 125/250 14-50R 3P 4W "RV" outlet---wouldn't the set up be safer with a gfi up stream?
there are 2 questions about the sched 40 pvc:
1. At the main panel I have the sched 40 pvc in an 18" deep trench--it goes verticle from the bottom of the trench to 18 inches above the ground level---above soil line--grade and then in to an elbo (pvc) and a box inside the house---it is not subject to damage a t the location it is--imho--I still have time to switch to sched 80 or to rigid---maybe I should just not do it and ask on my first inspection but the web search seems to say that it is a sugjective answer--is it in danger or not--who decides?--My inspector in the long run.
2. at the surface level of my slab where the sub panel will go and the 2 outlets---I put a threaded coupling on the sched 40 so the top of the threaded coupling is at the top surface of the slab and I planned to screw rigid in to that coupling and go up to the panel/outlets--is that Kosher?

 

[DaveMcSF]

I guess you lost patience with me!--O well, #1-this panel and the outlets are outside ona slab where I park and RV---I think it is safer--to have 110 GFI outlets and ---for the 220 and 125/250 have ;GFI breakers---I think this is safer because there will be rain-water--danger---Am I correct or not? #2 I am pulling 3-#4 and 1-#8 from the sub panel to the main house panel a---less than 200 feet in 1-1/2 inch sched 40 PVC buried 18 inch----at the house I need to go thru a pull box--in with rigid 1-1/2 and out with 1" flex--to the panel--- A---what is the min pull-box size and can it be a Cantex/PVC box (plastic sched 40)?-------B------Is one inch flex ok for 3-#4 thwn and 1-#8 G -Thanks guys

 

[Philly Master]

I guess you lost patience with me!--O well,

#1-this panel and the outlets are outside ona slab where I park and RV---I think it is safer--to have 110 GFI outlets and ---for the 220 and 125/250 have ;GFI breakers---I think this is safer because there will be rain-water--danger---Am I correct or not?


#2 I am pulling 3-#4 and 1-#8 from the sub panel to the main house panel a---less than 200 feet in 1-1/2 inch sched 40 PVC buried 18 inch----

at the house I need to go thru a pull box--in with rigid 1-1/2 and out with 1" flex--to the panel--- A---what is the min pull-box size and can it be a Cantex/PVC box (plastic sched 40)?------

B------Is one inch flex ok for 3-#4 thwn and 1-#8 G -Thanks guys

4 #4 in 1" Liquidtight Flexible Nonmetallic Conduit (LFNC-B)

does this help

 

[Philly Master]

now ....
#4 THHN is about $1 a foot .. or for you x3 ...$3 a foot plus ur ground ...


# 2-2-2-4 URD cable ( alum ) is about $1.25 per foot for everything ....and its wet location //

Next Panel ..

Main Breaker there is "almost" no savings on getting a main lug .. and you will need to buy extra Ground Bar since it is a sub panel

http://www.lowes.com/pd_374128-1318...t=main+breaker+panel&page=1&facetInfo=Siemens


Is this a covered space ?? do you need a wet/damp location panel also ??

 

[DaveMcSF]

Thank you so much for those answers---I had viewed a Murry 100Amp main sub and it looks to be the same as the Seimaqns you suggested I guess the min pulol box could be an "Elbo 1-1/2---thanks 1" liquid tite fles helps me get around the service feed in the wall at the main service panel--thanks Yes the slab is outlsid--the sub and all the outlets are outside so I am trying to look for rain tight/proof enclosures and THWN wire and gfi's---am I on the right track?

 

[Jim Port]

The panel will need to be 3R rated. The device boxes will need to be weatherproof with in use covers. The 120 volt receptacles will need GFI protection.

 

[DaveMcSF]

Thank you all for your comments and patience!
I have another question (of course) I just discovered "RV pedestal's"---but I cannot find what size wire nor how many wires need to go to the pedestal--so:
1. how many wires including ground?
2. What size wires?
It appears that at least in some the breaker is in the pedestal--maybe all---so no need for gfi bvrfeaker but what size would the panel breaker be?

 

[rjniles]

In an RV pedestal the 30 amp receptacle is 120 volt, you initial post said you needed a 240 volt 30 amp.

NEMA TT-30

Below is a 30 amp 240 volt 3 wire receptacle

NEMA Configuration10-30R

 

[DaveMcSF]

To clarify--
1. RV likes a NEMA 14-50R, 1-50 amp 120/240V RV service but will work on a 30 amp RV circuit or even a 20--all three are prewired in to a pedestal
--from what I see on the web
2. The 220 amp I mentioned is for 220 equipment that I have--like a compressor which needs true 220 (2 hots and a ground)-this would be in a separate enclosure 10 foot away from the RV enclosure

So what I am asking is how many wires and what size wire to a prewired pedestal that has the nema 14-50R and a 30 amp RV tyope outlet and a 20 amp--convenience outlet---are the feed wires shared?

Once I have these answers the question will be--will a 3/4 pvc be ok for these required wires and sizes?

 

[Philly Master]

nema 14-50R needs 4 wire, 2 hot, 1 neutral , 1 ground ... #8 copper

 

[DaveMcSF]

Sub panel to RV pedestal

A prewired pedestal has 3 outlets--- Nema 14-50R/3P,4W----30 Amp (TT30R)----- and 20 Amp GFCI Receptacle (5-20R2GFI)---the schematic shows Feeding this is 4 wires---Hot ,Hot, Neutral and ground

I would be going 30 foot from a sub panel--aI have 2 questions
1. What size wires from sup panel to prewired pedestal (50 amp sub panel)
2. Would those wire fit in a 3/4 pvc consuit?

One unrelated question---which I think would be NO:
1. Can I use regular 1-1/2 galvanized pipe to go from buried 1-1/2 sched 40 pvc---to an 1-1/2 elbow and then in to the garage wall to a pvc pull box--if I ream the pipe ?

 

[DaveMcSF]

Here is the pedestal schematic--no mention of wire size--should I make it 3 #6 +1 #10????--Whatis the correct size wire from the 50 amp sub panel to this pedestal??
Witt that wire fit in a 3/4 pvc conduit-(in concrete)