RV News RVBusiness 2021 Top 10 RVs of the Year, plus 56 additional debuts and must-see units → ×
 

Go Back   Thor Forums > Thor Tech Forums > Motorhome Tech Topics
Click Here to Login
Reply
 
Thread Tools Display Modes
 
Old 01-19-2021, 01:48 AM   #1
Junior Member
 
Cozy Cone's Avatar
 
Brand: Thor Motor Coach
Model: Hurricane
State: Michigan
Posts: 25
THOR #21795
Plugging 50 amp MH into 30 amp 240v socket

Hello, I have a 2011 Thor Hurricane class A motorhome. It has the large shore power cable with a 4-prong plug. I understand this is a 50 amp plug but does that mean the coach runs on a 240 volt power system? I have a 3-prong 30 amp, 240 volt plug socket in my garage that is used for a compressor or welder. Would it be safe to plug the coach into this socket using the 4-prong female to 3-prong male "dogbone" adapter? We don't really need to run much inside the coach over winter except maybe some occasional lights and occasional furnace. The main concern would be keeping the batteries charged. Any advice or help on this would be greatly appreciated! I don't want to risk damaging anything by using this plug socket. Thanks in advance for your help!
__________________

__________________
Cozy Cone is offline   Reply With Quote
Old 01-19-2021, 02:25 AM   #2
Site Team
 
EA37TS's Avatar
 
Brand: Entegra
Model: Accolade 37TS
State: Virginia
Posts: 4,904
THOR #1469
Don't do it because you'll fry the coach. 50 amp is basically 240 broken down into 2 separate 120 V circuits.
__________________

__________________
Dave
US Army (Ret)
2020 Entegra Accolade 37TS
2019 Jeep Grand Cherokee Trailhawk (Toad)
FMCA - F432054
EA37TS is offline   Reply With Quote
Old 01-19-2021, 02:34 AM   #3
I Think We're Lost!
 
Bob Denman's Avatar
 
Brand: Still Looking
Model: Tiffin Wayfarer 24 BW
State: New York
Posts: 18,501
THOR #8860
What he said...
__________________
Bob Denman is offline   Reply With Quote
Old 01-19-2021, 02:38 AM   #4
Senior Member
 
Brand: Still Looking
Model: Newmar Bay Star Sport 300
State: Alabama
Posts: 3,268
THOR #6826
Plugging 50 amp MH into 30 amp 240v socket

X2. Donít do it!
__________________
Pete'sMH is offline   Reply With Quote
Old 01-19-2021, 02:47 AM   #5
Axis/Vegas Enthusiast
 
JamieGeek's Avatar
 
Brand: Thor Motor Coach
Model: Axis 24.1
State: Michigan
Posts: 9,242
THOR #1150
If you just want to run the furnace and keep the batteries charged use an adapter and plug into the normal 120V 15a house plug.

Just don't try to run an A/C or something that way.
__________________
2014 Thor Axis 24.1
2021 Mach-E
blog - https://spareelectrons.wordpress.com/
JamieGeek is offline   Reply With Quote
Old 01-19-2021, 02:49 AM   #6
Junior Member
 
Cozy Cone's Avatar
 
Brand: Thor Motor Coach
Model: Hurricane
State: Michigan
Posts: 25
THOR #21795
Quote:
Originally Posted by Pete'sMH View Post
X2. DON’T DO IT! But you should be able to replace the outlet with the needed 4 hole one. The “extra” hole allows the two legs to be separate which your coach needs. With a bit more work and a junction box you could add the proper outlet adjacent to the one you have.
I thought the "Dogbone" adapter would allow for this by consolidation of the neutral and ground? So that's not the case? I am new to 50 amp powered coaches so that's why I want to gather as much info as possible. So would it be better in the interim to just step the 4-prong 50A plug down to a standard 3-prong 110v house socket and use that to keep the batteries topped off? Any problems associated with that?
__________________
Cozy Cone is offline   Reply With Quote
Old 01-19-2021, 02:51 AM   #7
Senior Member
 
Brand: Thor Motor Coach
Model: Citation
State: Texas
Posts: 506
THOR #8139
X3

Do not do it, however like Pete says if you no longer need the 240v it can be converted to a 120v 50amp outlet.

FYI don't think of the 120v50a cord going to your mh as 240v50a it is NOT.

Next time your in a 50a campground take a look at the breakerS in the pedestal, they'll both be 50a.

Then you can start thinking of you power cord as 2 120v 50a circuits wrapped in 1 sheath.



__________________
abjbrtd is offline   Reply With Quote
Old 01-19-2021, 02:52 AM   #8
Junior Member
 
Cozy Cone's Avatar
 
Brand: Thor Motor Coach
Model: Hurricane
State: Michigan
Posts: 25
THOR #21795
Quote:
Originally Posted by JamieGeek View Post
If you just want to run the furnace and keep the batteries charged use an adapter and plug into the normal 120V 15a house plug.

Just don't try to run an A/C or something that way.
Ok. I can do that. I don't intend to run anything except maybe the occasional light or two and the furnace on occasion but probably not for more than an hour or so at a time.
__________________
Cozy Cone is offline   Reply With Quote
Old 01-19-2021, 02:57 AM   #9
Junior Member
 
Cozy Cone's Avatar
 
Brand: Thor Motor Coach
Model: Hurricane
State: Michigan
Posts: 25
THOR #21795
Quote:
Originally Posted by abjbrtd View Post
X3

Do not do it, however if you no longer need the 240v it can easily be converted to a 120v 50amp outlet.

FYI don't think of the 120v50a cord going to your mh as 240v50a it is NOT.

Next time your in a 50a campground take a look at the breakerS in the pedestal, they'll both be 50a.

Then you can start thinking of you power cord as 2 120v 50a circuits wrapped in 1 sheath.



This does make sense. I have seen what you describe at the campground power pedestal. Thanks for the info!
__________________
Cozy Cone is offline   Reply With Quote
Old 01-19-2021, 04:18 AM   #10
Site Team
 
16ACE27's Avatar
 
Brand: Thor Motor Coach
Model: ACE 27.1
State: Florida
Posts: 5,674
THOR #7035
Quote:
Originally Posted by abjbrtd View Post
X3

Do not do it, however like Pete says if you no longer need the 240v it can be converted to a 120v 50amp outlet.

FYI don't think of the 120v50a cord going to your mh as 240v50a it is NOT.

Next time your in a 50a campground take a look at the breakerS in the pedestal, they'll both be 50a.

Then you can start thinking of you power cord as 2 120v 50a circuits wrapped in 1 sheath.




Actually, that's exactly what it is.

The OP could utilize the 240 VAC 3 prong source except it has no neutral, only a ground (or is it the other way around), and there is no "dogbone" adapter that would convert his 50 Amp plug to this receptacle.
__________________
Ted & Melinda
2016 ACE 27.1
2016 Chevy Sonic Toad
2020 Chevy Colorado Z71 Trail Runner Alternate Toad
16ACE27 is offline   Reply With Quote
Old 01-19-2021, 04:42 PM   #11
Junior Member
 
Cozy Cone's Avatar
 
Brand: Thor Motor Coach
Model: Hurricane
State: Michigan
Posts: 25
THOR #21795
Quote:
Originally Posted by 16ACE27 View Post
Actually, that's exactly what it is.

The OP could utilize the 240 VAC 3 prong source except it has no neutral, only a ground (or is it the other way around), and there is no "dogbone" adapter that would convert his 50 Amp plug to this receptacle.
As I have had explained to me, my understanding was that the 240vac 3-prong has the ground and neutral combined. So this would not be split properly into the two legs of 120vac that go into the coach by using a 4-prong female to 3-prong male dogbone (which does fit into that receptacle). Am I understanding that correctly?
__________________
Cozy Cone is offline   Reply With Quote
Old 01-19-2021, 05:32 PM   #12
Thor Palazzo 33.3 diesel
 
TurnerFam's Avatar
 
Brand: Thor Motor Coach
Model: Palazzo 33.3 34'bunkhouse
State: Georgia
Posts: 2,460
THOR #4735
no '3 prong' 240v outlet has any 'combined' Neutral and Ground - it actually has NO Neutral, ONLY a ground.

now, your 50amp 240v RV NEEDS both, not just one, so, no, you can't just 'plug into' this 240v outlet, even with an adapter.

technically: the reason a 50amp 240v RV needs the Neutral is because there is NEVER time when both 'sides' of the 240v power is balanced - the Neutral wire then provides that balancing. RVs, like your home's Main Panel, have a a Neutral because many things can be powered at the same time, but not 'equally' between the two 120v 'sides' of the panel.
For most other 240v outlets with only 3 wires, and no Neutral, they work for those appliances because the 'heating' element/power needs are exactly the SAME on both 'sides' of the power - so no Neutral is required, though most NEW Clothes Dryers use a 4-wire scheme now since a human can be TOUCHING the metal appliance WHEN a power leakage might happen - the Neutral wire then provides a secondary path, versus the human.
__________________
the Turners
'14 Palazzo 33.3 bunkhouse 34' diesel
KingTailgater2 Dish HD, 100w/5a SOLAR, BlueOx
110,000+mi since '14 - US, Alaska, Canada (also, '14 Gulfstream Amerilite and '07 ForestRiver Rockwood) : )b
TurnerFam is offline   Reply With Quote
Old 01-19-2021, 06:10 PM   #13
Junior Member
 
Cozy Cone's Avatar
 
Brand: Thor Motor Coach
Model: Hurricane
State: Michigan
Posts: 25
THOR #21795
Quote:
Originally Posted by TurnerFam View Post
no '3 prong' 240v outlet has any 'combined' Neutral and Ground - it actually has NO Neutral, ONLY a ground.

now, your 50amp 240v RV NEEDS both, not just one, so, no, you can't just 'plug into' this 240v outlet, even with an adapter.

technically: the reason a 50amp 240v RV needs the Neutral is because there is NEVER time when both 'sides' of the 240v power is balanced - the Neutral wire then provides that balancing. RVs, like your home's Main Panel, have a a Neutral because many things can be powered at the same time, but not 'equally' between the two 120v 'sides' of the panel.
For most other 240v outlets with only 3 wires, and no Neutral, they work for those appliances because the 'heating' element/power needs are exactly the SAME on both 'sides' of the power - so no Neutral is required, though most NEW Clothes Dryers use a 4-wire scheme now since a human can be TOUCHING the metal appliance WHEN a power leakage might happen - the Neutral wire then provides a secondary path, versus the human.
Fully understood. This was the kind of info I was looking for. I will not be using that receptacle. I would like to eventually convert it over to a 4-prong setup that will be appropriate for my MH. Thanks very much for your help and advice!
__________________
Cozy Cone is offline   Reply With Quote
Old 01-19-2021, 06:21 PM   #14
Member
 
droregon's Avatar
 
Brand: Thor Motor Coach
Model: Omni RB34
State: Oregon
Posts: 57
THOR #20891
This is a great forum! I learn new things everyday!
Thank you to all contributors.
__________________
droregon is offline   Reply With Quote
Old 01-19-2021, 06:46 PM   #15
I Think We're Lost!
 
Bob Denman's Avatar
 
Brand: Still Looking
Model: Tiffin Wayfarer 24 BW
State: New York
Posts: 18,501
THOR #8860
Question: I've got this old receptacle that was used for a dryer in my garage...What (if anything....); can I do with it?

https://www.thorforums.com/forums/at...1&d=1611082306
Attached Thumbnails
Click image for larger version

Name:	20210119_134716.jpg
Views:	55
Size:	154.7 KB
ID:	28126  
__________________
"The World is full of Kings and Queens; who blind your eyes, and steal your dreams."
Good Sam Member 843599689
Current coach: Tiffin Wayfarer 24 BW
Bob Denman is offline   Reply With Quote
Old 01-19-2021, 07:06 PM   #16
Member
 
Brand: Thor Motor Coach
Model: Miramar 35.3
State: Pennsylvania
Posts: 47
THOR #20808
So.... is the house side 3 prongs or 4 prongs, more importantly how many wires were run there?
The National Electrical Code currently requires 4-prong dryer outlets in all new home construction. Existing homes may still use 3-prong outlets. The switch to a 4-prong outlet was due to a flaw in the 3-prong outlet design. In a 3-prong outlet, the ground and neutral wires are contained in the same prong.
The little difference is the how the ground (or neutral) appears.... as an angle or round or U prong? Tells you the NEMA configuration of the receptacle. Note that RV plugs grounds are all U or round shaped..... NOT angle shaped.

So don't do it directly, the mentioned adapters would fit any how. However, can you replace the house side receptacle with the proper one for the RV? Depends. IF you have four wires (black, red, white and green) inside the house AND they are all connected at the panelboard properly you can install what you need. But this is more of a local electrician project to insure that you have the 120VAC from black to white and 120VAC red to white with ground connected (4 prong).

If the wiring in the house side is Black White and Green in the cable you can still get this wired but would need to change the breaker in the panelboard to single pole 30A then install a RV receptible. If the cable is Black Red and white or green (older) as a 3 - wire then you would need to wire and relabel the conductors.

Or just use the dogleg to 30A to 20A and run a few items that you need to keep it alive. Can't run an A/C much on 15A, 20A OK for just one.
__________________
pneumatics is offline   Reply With Quote
Old 01-19-2021, 07:14 PM   #17
Senior Member
 
macdaddy1111's Avatar
 
Brand: Thor Motor Coach
Model: Hurricane 35m
State: North Carolina
Posts: 274
THOR #13505
Unless I am missing something here?

I have 30 amp plug on side of house, I hook my RV up to it all the time. Had it install to keep power to our rig 24/7

240 volts is 240 volts.

I have 50 amp plug from rv, I plug into 30 amp dongle, 30 amp surge. Works like a champ!! Just can't run both ac's at same time.

If you are a 50amp rig and go to a park that only has 30 amp plug, what do you do if this is unsafe?
Attached Thumbnails
Click image for larger version

Name:	20210119_140202_resized.jpg
Views:	43
Size:	100.8 KB
ID:	28127   Click image for larger version

Name:	20210119_140232_resized.jpg
Views:	31
Size:	65.6 KB
ID:	28128  

Click image for larger version

Name:	20210119_140220_resized.jpg
Views:	28
Size:	90.5 KB
ID:	28129  
__________________
Retired Squid who has a retired squid that drives him around in a RV!
macdaddy1111 is offline   Reply With Quote
Old 01-19-2021, 07:41 PM   #18
Junior Member
 
Cozy Cone's Avatar
 
Brand: Thor Motor Coach
Model: Hurricane
State: Michigan
Posts: 25
THOR #21795
Quote:
Originally Posted by pneumatics View Post
So.... is the house side 3 prongs or 4 prongs, more importantly how many wires were run there?
The National Electrical Code currently requires 4-prong dryer outlets in all new home construction. Existing homes may still use 3-prong outlets. The switch to a 4-prong outlet was due to a flaw in the 3-prong outlet design. In a 3-prong outlet, the ground and neutral wires are contained in the same prong.
The little difference is the how the ground (or neutral) appears.... as an angle or round or U prong? Tells you the NEMA configuration of the receptacle. Note that RV plugs grounds are all U or round shaped..... NOT angle shaped.

So don't do it directly, the mentioned adapters would fit any how. However, can you replace the house side receptacle with the proper one for the RV? Depends. IF you have four wires (black, red, white and green) inside the house AND they are all connected at the panelboard properly you can install what you need. But this is more of a local electrician project to insure that you have the 120VAC from black to white and 120VAC red to white with ground connected (4 prong).

If the wiring in the house side is Black White and Green in the cable you can still get this wired but would need to change the breaker in the panelboard to single pole 30A then install a RV receptible. If the cable is Black Red and white or green (older) as a 3 - wire then you would need to wire and relabel the conductors.

Or just use the dogleg to 30A to 20A and run a few items that you need to keep it alive. Can't run an A/C much on 15A, 20A OK for just one.
House side is a 3-prong, 240v receptacle. Like you'd use for a dryer or welder (or in my case, an air compressor). My motorhome shore power cable has the 4-prong plug connector.
__________________
Cozy Cone is offline   Reply With Quote
Old 01-19-2021, 08:44 PM   #19
Member
 
Brand: Thor Motor Coach
Model: Miramar 35.3
State: Pennsylvania
Posts: 47
THOR #20808
macdaddy1111 has the set up. The 30A on the wall is 120VAC and runs from one single pole breaker in the panelboard. In fact this is the best way when a park only has 30A on the pedestal. One A/C with a few other items only.

What Bob has is old. Old. Don't use it, remove it. BUT you can repurpose the cable but need to replace the receptacle itself and then change the wiring in the panelboard to match. Written on the cable should be the wire size and # of conductors.

Search for NEMA plugs charts on the web and you can see the multitude of stuff that is out there.
__________________
pneumatics is offline   Reply With Quote
Old 01-19-2021, 09:24 PM   #20
I Think We're Lost!
 
Bob Denman's Avatar
 
Brand: Still Looking
Model: Tiffin Wayfarer 24 BW
State: New York
Posts: 18,501
THOR #8860
Thanks!
I know that setup is 58 years old...
__________________

__________________
Bob Denman is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Thor Industries or any of its affiliates. This is an independent, unofficial site.




All times are GMT. The time now is 07:51 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0 PL2
×