30 amp to 50 amp extension cords

[ron130fe]

I’ll be going camping in a couple of weeks and the campsite has old power and limited to 30 amps and quite a few campers in my group. My question is: I want to go from the power box with a 30’ 30amp extension cord and hook it into my 35’ 50amp cord to my 5er, I’m aware that I’m limited to 30 amps I just want to know if I’ll be overloading my 30 to 50 adapter or anything else. I’m also aware that I can only run 1 AC and will try and keep as much electrical equipment down to a minimum as I can. Does anyone see a problem with this situation, I’m new to the 5er and 50amp world.

Thanks for any input

[chuckster57]

We have done what your describing on numerous occasions in the shop. I can’t say the electrical system at my work is better than the campground your going to be at. Do you have an EMS or voltage monitor?

[ron130fe]

Yes I have a voltage regulator 30 and 50

[5J's]

I'd be real cautious. If you have a good EMS you'll be fine. The issue will be voltage drop over that length. Being you're only limited to 30 Amps you should be good. If you use a GOOD QUALITY EMS you should be fine.

[TheGriz]

I do exactly as you are describing when I am parked at home...50A 30' cord to my 30A 50' extension to my 30A RV receptacle on my house (dogbone in between). Maybe a minimal voltage drop...1 or 2 volts at most. I am always between 123V and 115V at the TT. FYI...I do have a PI hardwired 50A EMS.

UPDATE: I just decided to check under load. Before load, the EMS read both L1 and L2 at 123V. I turned on the 15K BTU A/C unit, and the voltage still was well within the safe zone of 118V with 0A on L1 and 26A on L2.

Mike

[shinobu8]

Depending on your AC type, you may be able to run both. We have a stock 15k BTU and added a second in the garage and we can run both on 30 amp.

[ron130fe]

How can you find the size of ac unit

[ron130fe]

What’s a dogbone

[chuckster57]

A “dog bone” is an electrical adapter with a male end and a female end with both ends being “different” as in the configuration (50A,30A,15A) you can pretty much get any combination. In my box I have a 50-30, 50-15, 30-15, 15-30.

[chuckster57]

Depending on your AC type, you may be able to run both. We have a stock 15k BTU and added a second in the garage and we can run both on 30 amp.



With only 30A TOTAL, I wouldn’t do it. Each AC unit is going to use about 13 amps when operating, leaving only 6 Amps for anything else. IF your second AC does start, I’m betting the compressor is slowly dying. Think of it as a mini heart attack, can only survive so many.

[sourdough]

I do exactly as you are describing when I am parked at home...50A 30' cord to my 30A 50' extension to my 30A RV receptacle on my house (dogbone in between). Maybe a minimal voltage drop...1 or 2 volts at most. I am always between 123V and 115V at the TT. FYI...I do have a PI hardwired 50A EMS.

UPDATE: I just decided to check under load. Before load, the EMS read both L1 and L2 at 123V. I turned on the 15K BTU A/C unit, and the voltage still was well within the safe zone of 118V with 0A on L1 and 26A on L2.

Mike

I know it has served you well but 80' of cable, some of questionable gauge, feeding my trailer from 30A would have me worrying a lot. Sounds like it works so...….

[TheGriz]

I know it has served you well but 80' of cable, some of questionable gauge, feeding my trailer from 30A would have me worrying a lot. Sounds like it works so...….

30A...10AWG. 50A...6AWG. If I saw voltage drop, or heating at any connection I'd be concerned. Also, not pushing the amp limits, nor is the OP from what he stated. Certainly though everyone has different comfort levels. :twocents:

[ron130fe]

Ok I have a couple of those 20-30 30-50

Thanks for great info

[TheGriz]

What’s a dogbone

Here is an example of a 50A female to a 30A male.

[Alpine]

Soooo can you just use a "dog bone" from the power post to your rv using only the 50amp cord? Or do you need the extra length... and that is why you would be using the 30amp cord as well? I may have missed something in translation!

[sourdough]

30A...10AWG. 50A...6AWG. If I saw voltage drop, or heating at any connection I'd be concerned. Also, not pushing the amp limits, nor is the OP from what he stated. Certainly though everyone has different comfort levels. :twocents:


I agree..if you are happy then no worries. I wouldn't run an 80' extension cord on a 30A/50A service with multiple connections, plugs and various size cables for anything....especially mixing gauges. JMO

[TheGriz]

Soooo can you just use a "dog bone" from the power post to your rv using only the 50amp cord? Or do you need the extra length... and that is why you would be using the 30amp cord as well? I may have missed something in translation!

If I understand correctly the first part of your post, you have a 50A RV and you want to plug into a 30A CG receptacle. Yes...plug the 30A male end of the dogbone into the 30A CG receptacle, and plug your 50A RV cord into the 50A female end of the dogbone. No need for the 30A extension cord unless you are too far from the CG receptacle and need the extra length.

Understand though that you are limited to just 30A in you RV when doing this.

Mike

[dmorgan64]

If the box only puts out 30 amps there will be no harm to the cord adapters! You will be limited to 30 amps (usage) on the RV. Adapter shall be fine.

[SummitPond]

How can you find the size of ac unit

I had to remove the interior grill holding the filter to find the sticker with the information on it. Not sure if it is in the same place for all units.

[JRTJH]

To expand on dmorgan64's comment: If you plug a 30/50 amp dogbone into a 30 amp outlet, the dogbone is designed to support 30 amps and no harm. If, on the other hand, you plug a 50/30 amp dogbone into a 50 amp outlet, then plug the 30 amp end into a 30 amp extension cord, plug that into a 50 amp service cord (which is protected by a 50 amp breaker in the trailer, the 30 amp section of the cord is not protected and can melt, burn or be destroyed if there is a draw greater than 30 amps inside the trailer. In other words, there are no safeguards to protect the "smallest" part of the cord, the 30 amp section. All of the circuit breakers are rated at 50 amps and that section of 30 amp cord can be overloaded with no properly rated circuit breaker protection.

[flybouy]

To expand on dmorgan64's comment: If you plug a 30/50 amp dogbone into a 30 amp outlet, the dogbone is designed to support 30 amps and no harm. If, on the other hand, you plug a 50/30 amp dogbone into a 50 amp outlet, then plug the 30 amp end into a 30 amp extension cord, plug that into a 50 amp service cord (which is protected by a 50 amp breaker in the trailer, the 30 amp section of the cord is not protected and can melt, burn or be destroyed if there is a draw greater than 30 amps inside the trailer. In other words, there are no safeguards to protect the "smallest" part of the cord, the 30 amp section. All of the circuit breakers are rated at 50 amps and that section of 30 amp cord can be overloaded with no properly rated circuit breaker protection.

Yup, in that scenario it would become a fusible link. Anyone who owed or worked on a Chrysler Corp vehicle in the late 60's -70's learned to curse at them.:banghead:

[66joej]

Yup, in that scenario it would become a fusible link. Anyone who owed or worked on a Chrysler Corp vehicle in the late 60's -70's learned to curse at them.:banghead:

^ YES. I remember working on the 60s Fords. They actually made the fusible link look like any other wire in the wiring harness.:banghead:

[sourdough]

Yup, in that scenario it would become a fusible link. Anyone who owed or worked on a Chrysler Corp vehicle in the late 60's -70's learned to curse at them.:banghead:

That extended right on up to the 90s Dodge trucks. Had a 90 Ramcharger leave me high and dry in the middle of absolutely nowhere due to blowing one. Found the bundle and figured that's what it was but didn't bring a test light, meter....zip. Pulled it out of the mountains back to the nearest town (65 miles), got some test equipment and fixed it. And yes, over the course of that day I had a few choice words for the link...and the truck:banghead:

[JRTJH]

Back in the day, I had a 87 YUGO that I bought to go back and forth to med school. That entire wiring harness was one big fusible link..... That said, that YUGO was less reliable than the Hyundai's of the period, if you can imagine..... No thanks, I'm not a fan of fusible links (or YUGO's) !!!!!

[66joej]

That extended right on up to the 90s Dodge trucks. Had a 90 Ramcharger leave me high and dry in the middle of absolutely nowhere due to blowing one. Found the bundle and figured that's what it was but didn't bring a test light, meter....zip. Pulled it out of the mountains back to the nearest town (65 miles), got some test equipment and fixed it. And yes, over the course of that day I had a few choice words for the link...and the truck:banghead:

How about those resistors on the firewall that you didn't know expired until your points burned out or welded together from too high a voltage?

[flybouy]

Yup, today's vehicles require the computers at NASA to diagnose and fix. Anyone else use the tinfoil from a pack of cigarettes to wrap around a glass fuse to get home?

[66joej]

Yup, today's vehicles require the computers at NASA to diagnose and fix. Anyone else use the tinfoil from a pack of cigarettes to wrap around a glass fuse to get home?

Hate to admit it but I used to have a short piece if 3/16" copper tubing in the toolbox. Put it in place of the buss fuse and quickly watch for smoke to locate the short/ground and take it out before anymore damage. Crude way of troubleshooting but hey it was the 50s and it worked.:hide:

[JRTJH]

Yup, today's vehicles require the computers at NASA to diagnose and fix. Anyone else use the tinfoil from a pack of cigarettes to wrap around a glass fuse to get home?

I remember those days far too well.... On my 71 LandCruiser, I remember building a new fuel pump diaphragm from an old inner tube so we could get back home. Ain't doing that on today's trucks....

And the first part of your statement ties into another thread very well..... Those NASA computers can readily detect that "performance chip" that you took out of the ODB connector just before you took it in for that slipping transmission or missing engine....... There's not much hiding anything from the onboard computers when the mechanic can tell you how fast you were driving, the date/time you did it and how much fuel was remaining when you started decelleration..... :facepalm:

[sourdough]

Hate to admit it but I used to have a short piece if 3/16" copper tubing in the toolbox. Put it in place of the buss fuse and quickly watch for smoke to locate the short/ground and take it out before anymore damage. Crude way of troubleshooting but hey it was the 50s and it worked.:hide:


Ha! Now I like that kind of trouble shooting - the smoke test. Earlier this year while in FL my HWH stopped working. Ran it down to the tiny fuse on the control board indicating something on the board was faulty. Been a long time since I ran trouble at a component level on a circuit board, plus they were all covered in plastic, so took a jumper wire and put it across the fuse connectors....poof! the faulty diode just smoked under the plastic. Problem found - new control board was 2 1/2 hours away in GA.

[66joej]

Ha! Now I like that kind of trouble shooting - the smoke test. Earlier this year while in FL my HWH stopped working. Ran it down to the tiny fuse on the control board indicating something on the board was faulty. Been a long time since I ran trouble at a component level on a circuit board, plus they were all covered in plastic, so took a jumper wire and put it across the fuse connectors....poof! the faulty diode just smoked under the plastic. Problem found - new control board was 2 1/2 hours away in GA.

Well I'll be Danny didn't think that sophisticated (think crude) method was still used.:D

[sourdough]

Well I'll be Danny didn't think that sophisticated (think crude) method was still used.:D

When the day is progressing, there's no hot water and DW WANTS hot water, and you're frustrated that a 1 yr. old hot water (I had just replaced it last year when the OE failed) heater has failed, and, I threw it away with a perfectly good control board, I was at the point in my frustration that I just wanted to see what "smoked"; hence my crude, but effective, trouble shooting method:D:hide: I could have just went to get the new board but I wanted the satisfaction of "seeing" the faulty component PAY for my inconvenience!:banghead::lol:

[flybouy]

When the day is progressing, there's no hot water and DW WANTS hot water, and you're frustrated that a 1 yr. old hot water (I had just replaced it last year when the OE failed) heater has failed, and, I threw it away with a perfectly good control board, I was at the point in my frustration that I just wanted to see what "smoked"; hence my crude, but effective, trouble shooting method:D:hide: I could have just went to get the new board but I wanted the satisfaction of "seeing" the faulty component PAY for my inconvenience!:banghead::lol:

Ah the price of revenge, I know it well....:banghead: