Amps and Volts

Verna

This discussion was created from comments split from: Alde heat and hot water.

fwillison

Amps and Volts are independent.  A 30 Amp cord can carry 110/120V or 220/240V depending on how it is put together. A 30 Amp service can be supplied as 110/120V or as 220/240V.  Stating 30 Amps relative to the cord only means the size wire in the cord can safely carry up to that current regardless of the voltage.  It can flow additional current and does not limit the current - It just gets hot and burns the insulation at the higher current.  

The current is only limited by the breaker.  Not the cord.

lapowers57

Having rewired a boat and a house, electricity is a very interesting subject.  There are many books out there that will give you some basic theory and then provide cookbook steps on how to perform many basic wiring projects.  While everything that fwillison said is correct I have found that in the world of RV's and generators that 30 amp usually refers to a source that is single phase (can only be 120 volt), that provides 30 amps of power and uses a plug with one hot prong one neutral prong and one ground prong.   While 50 amp usually implies that it is two phase (can be 120 or 240 volts) and uses a plug with two hot prongs, one neutral prong and one ground prong.  It is all very confusing and that is why being able to recognize what type of power source is at campsite is important.  And also to have some adapters so you can make do when the standard 30 amp receptacle that the T@B's use is not what you find at your campsite.

Michigan_Mike

For the most part the majority of campgrounds will have 30 amp hook-ups and a standard residential style GFI equipped electric receptacle inside their pedestals.  Some updated pedestals do have dual 30A & 50A equipped receptacles.  The 50A hook-ups are for the larger motor coach type rigs that need power for things like ovens, clothes dryers or anything using 240V.  It can be a bit confusing to people who are new to RV use and that comes with the turf and is expected as we were all new users (or newbies) at one point in time and this is how we learn, gain experience and become more comfortable with each outing.  

On the flip side I have stayed in older RV parks down in places like Florida where there are still some old 20A electrical systems that exist and that require a 20A adapter for the standard 30A power cord that comes equipped on T@B units and other Little Guy units wired for 30A service.  

YouTube has many helpful/useful videos dealing with the above and a quick search will yield many dealing with this topic.  The first video deals with a brand specific trailer but it does give a basic over view as does the following video.  

https://youtu.be/mRD-baSYyUM?t=9

https://youtu.be/7DpIzugALqc?t=3

Ratkity

In many state parks in DE, MD and VA there are only specific sites that offer 50A service. The other electrical pedestals have just a 30A and a couple 20A receptacles. Interestingly, I found out from a friend who bought a huge land yacht camper recently that he only has a 30A converter!! Companies are expecting people to use gas appliances (hot water heater and frig specifically) when on shore power - even with these huge campers! (30+ feet and 2 slide outs).

We found out while camping with them and their land yacht that when he ran his frig, air, and microwave at the same time that the main breaker flipped. A little sleuthing found his hot water heater and frig gas modes weren't functioning. Some online folks said the trifecta of hot water heater with the air and microwave was a sure bet that the breaker would flip off.