Receptacle Configurations

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steve66

steve66

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Illinois
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Engineer
Can anyone identify the receptacle configurations for the 50A, and 30A outlets below? Is the middle pin just a pin, or is it an electrical ground?

If its a ground, I'm not sure why the 50A receptacle has 5 connections? Its supplied with a 2 pole breaker, so it can't be 3 phase.

Also, is it code compliant to supply this pedestal with either 208 or 240 volts?


IMG_2129.jpg

They don't appear to be standard NEMA configurations, so I thought they might be "California" style devices, but they don't seem to match those either. I also did a search for "non-nema receptacle configurations" and still couldn't find any that look like these.

Thanks:
Steve
 
The middle holes are not contacts, they're for the rivets that hold the front and back half of the receptacles together. The 50-a receptacle is the same as a 120/240v, 50a 4-wire range receptacle (14-50R), and the 30-a receptacle is a 120v, 30a TT-30R (travel trailer).
 
Yep, that's a common box at RV parks so any RV can plug in without adapters.

Small RV's will just have your standard household type 120V 15A plug for a NEMA 5-15R or 5-20R.
Medium RV's will have the RV-only non-NEMA 120V 30A TT30 (TT = travel trailer).
Large RV's will use the 120/240V NEMA 14-50, same as most electric ranges, but the RV doesn't have 240V loads, but uses it as basically a feeder for the panel in the RV and balances the 120V loads.

As mentioned, that middle hole in the larger two is a screw or rivet holding it together.

The fact that your pole-to-pole voltage is 208V instead of 240V won't matter to an RV. It only uses the pole-to-ground voltage.
 
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OK, thanks. I only have the photo, and the rivets were throwing me off. Especially on the 50A - that really looks like another connection.

But this photo makes it a little more obvious:
NEMA_14-50R.jpg
 
jumper said:
What is “California” style?
Click to expand...

https://www.stayonline.com/reference-california-standard.aspx

I didn't know where the name came from until now:
NoteEarly Non-NEMA 50 Amp wiring devices were eventually rejected by the State of California governing agencies. The next generation of Non-NEMA 50 Amp North American Twist-Lock products have a CS proceeding the balance of the part number to note California Standard (CS). These products have gained popularity in number of applications from marinas to data centers.
Click to expand...
 
Keep it on topic please. This is not campfire....

But my opinion is that when there is a missing configuration in a standard product lineup (like NEMA receptacles) that fills a regulatory need in CA, the market is large enough that it will be produced without a national standard.
 
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