Looking for a 50 Amp plug in box.
 

Looking for a 50 Amp plug in box.

Started by Wax-um, July 25, 2010, 06:37:14 PM

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Wax-um

Anyone know were I can find a 50 amp 4 prong box with male inlet to plug in standard shore power extension cord. I could hard wire in shore power cord into a junction box but I thought a plug would be alot cleaner.

Sean

The standard "inlet" used for detachable 50-amp shore cords is a Marinco item.  It has three "prongs" and a grounding collar, and is the twist-to-lock style.  They are available in either plastic or metal from a variety of marine suppliers (e.g. West Marine, Defender, etc.) and also Camping World as well as many other RV suppliers:

http://www.marinco.com/product/50a-125250v-standard-rv-power-inlet

-Sean
http://OurOdyssey.BlogSpot.com
Full-timing in a 1985 Neoplan Spaceliner since 2004.
Our blog: http://OurOdyssey.BlogSpot.com

Stormcloud

Mark Morgan  
1972 MCI-7 'Papabus'
8v71N MT654 Automatic
Brandon, Manitoba, Canada in summer
somewhere near Yuma, Arizona in winter(but not 2020)

belfert

What I have on my bus is the inlet Sean linked to.  It was easy to install.  The other kit seems like a lot more parts.

Hubbell also makes compatible parts, but I mostly have seen the Hubbell in 30 amp.
Brian Elfert - 1995 Dina Viaggio 1000 Series 60/B500 - 75% done but usable - Minneapolis, MN

Wax-um

Quote from: Sean on July 25, 2010, 07:21:37 PM
The standard "inlet" used for detachable 50-amp shore cords is a Marinco item.  It has three "prongs" and a grounding collar, and is the twist-to-lock style.  They are available in either plastic or metal from a variety of marine suppliers (e.g. West Marine, Defender, etc.) and also Camping World as well as many other RV suppliers:

http://www.marinco.com/product/50a-125250v-standard-rv-power-inlet

-Sean
http://OurOdyssey.BlogSpot.com


I like that, now If I can find an affordable 30ft cordset for under 150 bucks I might order it if not Ill hard wire my cord I have now.

Sean

Quote from: Wax-um on July 25, 2010, 08:29:58 PM
I like that, now If I can find an affordable 30ft cordset for under 150 bucks I might order it if not Ill hard wire my cord I have now.

I've seen such cords for as little as $75, but you need to hunt around.  They come up on eBay occasionally, so set yourself an email alert there.

If you already have an appropriate 6-gauge, 4-wire cord, all you really need is the female end to mate with the bulkhead connector, and those can be had for $20-$30 if you hunt.  The link that Stormcloud posted is a kit that includes the male inlet that goes on the coach, as well as the mating female connector that goes on your existing cord, all for $160.  That's a good price, but you can do better with fortuitous timing on eBay;  I once picked up two of the female ends for $15 apiece (they were mated to 18" cords with molded 30-amp plugs).

-Sean
http://OurOdyssey.BlogSpot.com
Full-timing in a 1985 Neoplan Spaceliner since 2004.
Our blog: http://OurOdyssey.BlogSpot.com

steve wardwell

I found the 50/240 female end for my cord at a RV store for $20. It makes rolling and storing it a breeze.  I'll Never go back to the hard wire !
Sometimes the more I think about something the less I think about something.    As soon as I save a little money my bus finds out.                                      Why grab a plane when you can take the bus ?                         If I'm wrong 10% of the time how can the "Queen" be right 100%

BG6

I decided not to spend an extra hundred-plus dollars to make it easy for someone to steal my shorepower line.  I hardwired.  It is SLIGHTLY more work to coil up the line that way (compared to unhooking both ends, coiling and tossing it into the service bay), but I saved money, saved the effort of installing the box, and my cable is still there even after the guys on each side of me (and a dozen others) lost theirs one night in a park in the People's Republic of California.

steve wardwell

Sometimes the more I think about something the less I think about something.    As soon as I save a little money my bus finds out.                                      Why grab a plane when you can take the bus ?                         If I'm wrong 10% of the time how can the "Queen" be right 100%

Sean

Quote from: BG6 on July 26, 2010, 09:17:56 AM
I decided not to spend an extra hundred-plus dollars to make it easy for someone to steal my shorepower line.  I hardwired.

FWIW, an easy way to achieve the same objective yet still have the convenience of a detachable cord, is to mount the inlet inside of a locking bay, rather than on the coach exterior.  This has the additional advantage of allowing you to be more lax about sealing up the whole contraption.

There are other advantages of a detachable cord system as well.  We carry three different cordsets; one is the traditional 6-gauge, four-wire, 25' long 50-amp shore cord.  One is a 10-gauge, three-wire, 50' cord for use with 30- 20-, and 15-amp services that is much easier to manage and reaches farther.  The last is a 10-gauge 3-wire cord that is only 18" long and terminated with a 20-amp plug.  We use this in places where someone has provided us power in the form of an extension cord running out of their facility.

QuoteIt is SLIGHTLY more work to coil up the line that way (compared to unhooking both ends, coiling and tossing it into the service bay), ...

Probably true if you have designed your bay floor/door setup with a notch or similar arrangement such that the cord does not first need to be fished through an exit hole in the floor or door to deploy or retrieve.  Many coaches will not have this option, because to make such a notch would require cutting through structural tubes.  I know we could not do it, for example.  When I had a Fleetwood motorhome, it had a permanently attached cord, and to properly set up, I'd have to feed the entire length of it through the circular hole they provided in the bottom of the compartment, and it was a total PITA.  If I was just spending a single night I would more often than not just leave the bay door ajar with the cord hanging out.

The other issue here is that it means your service entrance must be in the same bay that has room for the cord storage.  Having a detachable cord gives you the flexibility to install the entry J-box in a place that is more convenient for wiring purposes, or more appropriately located along the length of the coach, and letting you store the cord(s) elsewhere.

There is no doubt whatsoever, though, that a detachable cordset is more expensive than a hard-wired one. Moreover, if the inlet is mounted on the coach exterior, it additionally mandates the more expensive transfer-switch option versus the less expensive tried-and-true receptacle method of generator attachment.

Quote... my cable is still there even after the guys on each side of me (and a dozen others) lost theirs one night in a park ...

FWIW, if the thieves' objectives are to salvage the copper (far more likely than trying to fence the cord itself), they'll just cut it off anyway.  So you dodged a bullet, probably because there were easier targets on either side of you.  We avoid this scenario by staying out of target-rich environments  ;) and I will say that we've never had a cord stolen in six full years on the road.  Of course, we're not plugged in very often, either.

Quote
... in the People's Republic of California.

JMO, but I don't think this sort of a political slam belongs here.  FWIW, we have not found California any worse than most other states in any respect that matters to RV visitors.  As long-time Californians, I probably have other things I could say about the state, but the bottom line is nobody forced me to live there for 20-odd years, so clearly I felt the benefits outweighed the costs.

Crimes of opportunity happen in every state, and California is not anywhere near the top of the list.  But in any case, such a discussion probably belongs at least in a separate thread.  As I said, JMO.

-Sean
http://OurOdyssey.BlogSpot.com
Full-timing in a 1985 Neoplan Spaceliner since 2004.
Our blog: http://OurOdyssey.BlogSpot.com


steve wardwell

 Got to say this, After using marine 50/240's for 20 years I'm happy I don't have to spend the money for them anymore, and Ive spent a lot on them !while they are nicely made and sometimes water resistant the problem as I see it  is the contacts are so small and  don't last nearly as long as an RV plug will...In usage everyday a plug would last not more than 3 years tops.I was twin 50s over the years I musta bought a dozen or more.  Ho boy ! I used grease and kept the amps down. But they didn't hold up well.I do realize the salt water environment is harsh but heck Marineco or hubbell was about $80 and up for a half a plug.............................my 2 cents ........s...........
Sometimes the more I think about something the less I think about something.    As soon as I save a little money my bus finds out.                                      Why grab a plane when you can take the bus ?                         If I'm wrong 10% of the time how can the "Queen" be right 100%

belfert

Marinco is just a standard NEMA locking plug with a waterproof cover if I recall correctly.  I would have to go out and look at mine to see for sure.  I have no idea why they wouldn't last in RV use.  These types of plugs are used in industrial settings without the covers all the time.

Edit: Per Sean, this is not a NEMA standard plug although it is the same concept as a NEMA locking plug.  I guess I should have gone out and looked before posting.  It sure looks like most NEMA standard locking plugs.
Brian Elfert - 1995 Dina Viaggio 1000 Series 60/B500 - 75% done but usable - Minneapolis, MN

steve wardwell

I always felt the contacts were small. Periodic bursts,  the AC running while the coffee pot on and then oops the toaster ...possable lo voltage on the docks  whatever the pins would start to show tiny points of heat then grow until they failed taking out 3 feet of cord with it. I just think the bigger the contacts the less problems....remember those old switchblade throws? lots of copper,big, good stuff....don't get me wrong, marine is good,but if I had a choice I'd go for overbuilt  and cheaper.
Sometimes the more I think about something the less I think about something.    As soon as I save a little money my bus finds out.                                      Why grab a plane when you can take the bus ?                         If I'm wrong 10% of the time how can the "Queen" be right 100%

Sean

Quote from: steve wardwell on July 26, 2010, 06:28:44 PM
Got to say this, After using marine 50/240's for 20 years I'm happy I don't have to spend the money for them anymore, ...

Unfortunately, it is the only game in town if you want a detachable cordset.  The only other legal alternative would be a NEMA L14-50, however, I have never seen a listed L14-50 male inlet and I don't think anyone makes one today.  Marinco pretty much defined the market for this, and now everyone else makes a compatible part (Hubbell, Bryant, etc.).

FWIW, the tangs on a Marinco or compatible 6365 connector have no less contact surface than a NEMA L14-50, and only slightly less surface than a non-locking 14-50 (where the tang surface also serves as the retention mechanism).

Quote from: belfert on July 26, 2010, 07:26:26 PM
Marinco is just a standard NEMA locking plug with a waterproof cover if I recall correctly. ...

Many people think that, but it is not correct.  The industry, which one might argue is the definitive constituent of NEMA, has adopted the Marinco standard de facto, however, NEMA itself has not adopted this as a standard.  The correct NEMA standard for twist-to-lock, 50-amp, 125/250 VAC, four-wire, split phase service is the L14-50P/L14-50R, which has three circumferential tangs for the current-carrying conductors, and a round axial tang in the center for the ground.  It is similar in size and identical in function, but the two will not mate.

The industry uses the number 6365 to identify the Marinco-style part.  This system has only three circumferential tangs, with the ground being provided by a grounding collar on the connector.  This means that a "plug" (the male connector) must have its three tangs recessed into a round well the depth of the ground connection, making for an unusual looking plug, and thus substantially different from any NEMA style.  However in practice, "plugs" are seldom seen loose in this arrangement, almost universally being recessed into a bulkhead inlet, which is what the connector was originally designed for.

Here is a photo of a loose 6365 plug, so you can visualize how different it looks from any other type of twist-to-lock plug:



Note that such a plug really only sensibly mates to loose female connectors (no pun intended) such as the ones on the ends of shore cords, because a flush surface-mounted female outlet would require an annular recess to accommodate the grounding collar.

For "conventional" cord-and-plug connected appliances requiring locking arrangement, the cord would be more appropriately fitted with a NEMA L14-50P and the permanent receptacle would be a NEMA L14-50R, which has no need for the annular recess and resulting additional receptacle depth.

-Sean
http://OurOdyssey.BlogSpot.com
Full-timing in a 1985 Neoplan Spaceliner since 2004.
Our blog: http://OurOdyssey.BlogSpot.com