Power supply confusion...

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Joined
May 20, 2022
Posts
6
Location
New Hampshire
Might not be the place for this but I'm desperate! Any advice would be so appreciated. I've recently gotten a travel trailer that was originally manufactured in China, and I'm trying to figure out how to power it but I'm really confused as to the setup. The outer plug is an L14-30P that was labeled (with a sticker) 110v. There are two mini 230/400v circuit breakers inside and 6 standard outlets, as well as a couple LED lights. I have a Honda eu7000 that I connected it to and I wasn't able to get anything at all working on 120v 30A. The generator has a voltage selector so I momentarily switched it to 240v (I know, I've learned this was probably a bad idea) and when I did that the lights powered on and an appliance that I had plugged in did as well. I shut it off pretty quickly to be cautious. I did a multimeter test and with the generator running at 120v the outlets were only putting out 50v, and with it running at 240v the outlets were putting out 253v! Can anyone help me figure out how this is wired and how I should be powering it?? I want to be safe, of course, and don't want to be providing too high a voltage but it just will not power up at 110v. What am I missing?! Any help would be amazing, thanks so much.
 

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The pictured breakers are labelled for 230 VAC.

Don't any of you onboard appliances have a name plate that says what voltage they need?

The company has no on-line information and provided no "packing material literature?" The trailer just showed up on your doorstep?

Is there no company name on the trailer so you can google it and make contact?

What is the year and make - perhaps you don't know? Even if the characters are all in Chinese we have a world-wide forum and some member may be able to read and name or documentation and help direct you.
 
What am I missing?! Any help would be amazing, thanks so much.
China uses 220 VAC at 50 hz. That includes Hong Kong and Macau. If that rig is made for China it is expecting to see 220VAC at 50 hz. But I would expect 60hz to still work for most of the stuff in it.

A L14-30P can be either for 120 or 240 VAC.

What I would do first is check the voltage input labels on all the AC equipment inside and see what voltages they are designed to run from.

-Don- Auburn, CA
 
Thanks for the reply! I'm in contact with the company and they're insisting that the trailer is wired for 110v and all appliances are 110v, but the plug for the fridge/freezer is clearly a 240 and nothing on board will work when hooked up to the gennie at 120v. Do you know of any reason why the full voltage (roughly 250v) would be coming through the outlets when the selector is on 240v and only 50v coming through the outlets when the selector is on 120v? That's the part that I'm really confused by... Thanks for taking the time.
 
China uses 220 VAC at 50 hz. That includes Hong Kong and Macau. If that rig is made for China it is expecting to see 220VAC at 50 hz. But I would expect 60hz to still work for most of the stuff in it.

A L14-30P can be either for 120 or 240 VAC.

What I would do first is check the voltage input labels on all the AC equipment inside and see what voltages they are designed to run from.

-Don- Auburn, CA
The trailer was made in China but was supposed to be to American standards, but there are both 240v (fridge/freezer) and 120v (water pump) appliances on board, which has me super confused!
 
nothing on board will work when hooked up to the gennie at 120v
Because the devices don't operate at that voltage, or the current isn't reaching the devices? You are playing with fire to arbitrarily apply 240VAC to anything until you conclusively verify that's the power source. How are the sockets actually wired? I would be rooting through the service panel to see what's coming in, how it's divided (2 hots + neutral? 2 hots? 1 hot?) and how devices are connected.

Mark B.
Albuquerque, NM
 
Do you know of any reason why the full voltage (roughly 250v) would be coming through the outlets when the selector is on 240v and only 50v coming through the outlets when the selector is on 120v?
What type of outlets? Are they all 14-30's? If so, measure the 120 VAC voltages to neutral, not ground. Across the "x" and "y" as shown above in message number 7, for the 240 VAC.

-Don- Auburn, CA
 
Because the devices don't operate at that voltage, or the current isn't reaching the devices? You are playing with fire to arbitrarily apply 240VAC to anything until you conclusively verify that's the power source. How are the sockets actually wired? I would be rooting through the service panel to see what's coming in, how it's divided (2 hots + neutral? 2 hots? 1 hot?) and how devices are connected.

Mark B.
Albuquerque, NM
and verify that all appliances are 60hz not 50hz
 
Another very important detail is to understand the 2 electrical supply plugs shown in your original post. Typically, there would only be a single supply method to plug into the RV. Yours has two separate plugs presumably for 30amp and 50amp. It is important to know how they have this wired and how the unused plug is being isolated if it is at all. They may claim to have set this up to American standards but to really follow that rule, it would take an understanding of what is being done and how. Not everything is written. There is also a possibility that everything is not done by American standards and that there may be some risks involved with the design.

If you are finding 250volts at all your outlets, that alone is safe to say that something is very wrong. There should not be anyway to do this other than wiring it specifically for 250volt with the proper outlets or the supply wiring (generator, pedestal, cord etc) has been wired incorrectly and you plug it into the RV.
 
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It sounds like you need to map out the entire electrical system before you proceed. If there is no mfg. Info available, you have to create your own. There are economical tracing devices available, or contact a capable electrician to help. Good luck, and be safe!
 
It is possible that it is using both, as an L14-30P can have 120 VAC as well as 240 VAC.

View attachment 154050
Thanks, Don- just disassembled the camper side of the L14-30 plug and the hot and neutral were connected to the left and right prongs, there were two grounds attached to the ground prong and no wires attached to the other one. Does this tell me anything? Trying to get an electrician out here but I'm pretty rural and they're booking months out.
 
Another very important detail is to understand the 2 electrical supply plugs shown in your original post. Typically, there would only be a single supply method to plug into the RV. Yours has two separate plugs presumably for 30amp and 50amp. It is important to know how they have this wired and how the unused plug is being isolated if it is at all. They may claim to have set this up to American standards but to really follow that rule, it would take an understanding of what is being done and how. Not everything is written. There is also a possibility that everything is not done by American standards and that there may be some risks involved with the design.

If you are finding 250volts at all your outlets, that alone is safe to say that something is very wrong. There should not be anyway to do this other than wiring it specifically for 250volt with the proper outlets or the supply wiring (generator, pedestal, cord etc) has been wired incorrectly and you plug it into the RV.
Thanks, Henry. Learning a lot with this project and appreciate your insight. Trying to get an electrician out but having a very hard time. Disassembled the supply plugs and the wiring is shown below- do you have any insight on this? the L14-30 has a hot and neutral on the left and right prongs, two grounds on the ground prong and no wires connected to the neutral. Thanks so much for taking the time to provide info.
 

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Because the devices don't operate at that voltage, or the current isn't reaching the devices? You are playing with fire to arbitrarily apply 240VAC to anything until you conclusively verify that's the power source. How are the sockets actually wired? I would be rooting through the service panel to see what's coming in, how it's divided (2 hots + neutral? 2 hots? 1 hot?) and how devices are connected.

Mark B.
Albuquerque, NM
Here's a photo of the socket wiring as well as the outer plug I've been connecting to- I unplugged everything and the sockets say they're rated to 250V but I was still definitely hesitant to apply 240v.
 

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Here's a photo of the socket wiring as well as the outer plug I've been connecting to- I unplugged everything and the sockets say they're rated to 250V but I was still definitely hesitant to apply 240v.

Looking at your pictures trying to make sense of this. Hopefully others are doing the same.

My only suggestion at this point is to not apply voltage to anything until you are absolutely sure of what it is doing and where it is going. I say this reading your post above and just want to remind you that the rating of any plugs, outlets wire etc, is not a pass to connect 250 volts to them. Be careful and it looks like you will need to start mapping things out and wait for an electrician to come and get you going in the correct direction.
 
Does this tell me anything?

Thanks, Don- just disassembled the camper side of the L14-30 plug and the hot and neutral were connected to the left and right prongs, there were two grounds attached to the ground prong and no wires attached to the other one. Does this tell me anything? Trying to get an electrician out here but I'm pretty rural and they're booking months out.
What it looks like to me is neutral and ground is tied together with the two yellow wires.


The red to blue will be 240 VAC.

Red to ground/neutral as well as blue to ground/neutral will be 120 VAC.

-Don- Reno, NV
 
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