Community Forums

mikeye74 · 08-03-2011, 05:59 PM

Hi I just purchased a 1974 Kencraft trailer and it seems to have
240v 80 amp power. It has a 40amp rated cord into a power
box that starts with two 40amp curcits. my problem is that I need
to hook up to dry outlet and cant find an adapter with those type
of blades...I have adapters to power off of 115v 15amp but this is
not enough power. Does anyone know about these trailers or any
ideals what to do. Thank you for any help you can send my way.

mahon1993 · 08-03-2011, 06:23 PM

Before you plug anything in be sure you know what you are dealing with. I am not familiar with a 1974 Kencraft trailer but I don't think it needs 240 volts to operate. The 240 volt 80 amps you mention, are those just the maximun power ratings of the breaker box and the power cord that are stamped or printed on them? Do you have an owners manual for it? That would tell you a lot. If not, I would suggest that you get a friend that is familiar with RV's to look at it, or an electrician to see what you are dealing with. Somebody might of changed the power plug to fit an outlet they had at home not using a standard RV plug. You don't want to plug anything in until you know what you are dealing with. You could blow things up and/or cause a fire. Can you post some pictures of what you are talking about?
Greg

mikeye74 · 08-03-2011, 06:40 PM

thanks for the reply. I currently have it powered on 115v and its working good,
but Im only using the lights and a small fridge I put in. I will post pic's shortly and would appriciate your feedback on what you think on what you see. Pretty much yes to all your questions except no to the owners manual. I thinks it is240v split at the box into two seperate 40amp 115v circuits. Would this be
normal for the time era??? thanks again back shortly with pic's

TXiceman · 08-03-2011, 06:46 PM

VintageTrailerEnthusiasts : Vintage Trailer Enthusiasts

Check this vintage group as well. They may know more about the Kencraft.

I doubt if a trailer of that age was factory wired for 240 volts. If was probably modified.

Ken

mikeye74 · 08-03-2011, 07:17 PM

Yes I will check that out and thanks here are the pic's of this unit thanks again

wa8yxm · 08-04-2011, 10:36 AM

If the plug it came with has 3 flat blades and one round or U shaped one then the service is not 240 volt, it's 120/240 volt and hooking to a dryer outlet is.. DANGEROUS.

I will explain why... (And I will talk about 50 amp rv's since this unit should plug into a 50 amp outlet)

In a 50 amp RV, generally speaking everything runs on 120vac or 12vdc, We will pay attention only to the AC side.. It's all 120 volt, no 240 volt anything save for possibly a sensor in the EMS if you have one (Energy Management System) that is the only 240 volt device, it's job, to detect when you are plugged into a proper 50 amp outlet.

Now, the reason for the 120/240/120 volt system is power loss. Let's say I'm running one air conditioner, nothing more.. Well there is power loss in the HOT wire coming to the rig from the transformer.. And more in the NEUTRAL hauling the current back to the transformer. Let's say 1 volt each way, 2 volts total or 200/120 volts percent loss

Now let's fire up the OTHER Air conditioner, same size, same requirements.

Now we have a voltage loss in the hot leg for the first, and we have an identical loss in the hot leg for the second. NO CURRENT FLOWS IN THE NEUTRAL since it's returning via the other hot leg.. Our loss is now 200/240 percent (1/2 of what it was)

This is the reason for doing it that way.

Now the danger:

The dryer outlet has 3 wires, not 4, the missing wire is often the NEUTRAL.. People think "Well I can use the ground, after all , they connect together at the main service entrance panel" which is true as far as it goes.

But if you have say 6ga wires feeding the hots.. You may well have 12 ga for the safety ground (Smaller wire for that lead is often within code) and when you try to haul a full 50 amps on just one leg.. The fire department still makes house calls.

mahon1993 · 08-04-2011, 11:57 AM

Hows bout a picture of the plug you have.
Greg

mikeye74 · 08-04-2011, 03:52 PM

thanks guys for the info and yes it is a 3 flat blade and 1 round one here is a pic of it,,, so what type of set up do I need to plug into to get the proper power at home.

ernieh · 08-04-2011, 04:05 PM

The black plug looks like a 50A RV.

A 50A 4 wire range plug is virtually identical.

Lowes has both surface and flush mount recepticles that will work.

If you need more information, someone else should probably make the connection.

Be safe out there.

mikeye74 · 08-04-2011, 04:06 PM

not burned just old so I guess my thought that this is 240v split at the box (similar to a dryer, two 120v in one plug) is incorrect then. So is what I need
a 50amp 120v outlet??

Road Pilot · 08-04-2011, 04:57 PM

Mike, a 50 amp rv connection has a ground , a neutral and two 120 vac hots. If you measure from hot to hot you get 240 vac. Each leg(neutral to one hot) is good for 50 amps. Most rv's don't use the 240 vac that's available, but some do. Mine uses the 240 vac, so when I'm on a 30 amp connection I can't use my dryer.

If your dryer is one of the newer 4 wire connections it's very similar to the rv connection and an adapter will work well. If it's an older style 3 wire, you want to be very careful. Many folks have blown up their rigs by simply connecting one of these.

okmunky · 08-04-2011, 05:18 PM

I saved this link to help me understand RV electrical issues.

RV Electric

mikeye74 · 08-04-2011, 05:23 PM

thanks you very much that site is AWSOME and has what Iam looking for
thanks again to you all

Ray,IN · 08-06-2011, 03:46 PM

Only high-end custom-built motor homes(or home-made RV's) have 240VAC inside the coach, I know of no towable with 240VAC inside. The RV Electric website explains it all very clearly. If you plug into a 3-prong dryer outlet it will let all the smoke escape from the appliances and they no longer work.