For our Electricians concerning 50 vs 30 AMP... - Montana Owners Club

Glenn and Lorraine · 05-01-2009, 12:00 AM

I could answer this question myself by hooking up to a 30 AMP service but I am lazy and I'd rather not switch over from 50 to 30 just as an experiment.

Question is, When I am hooked up to 30 AMP do I still have power to the washer/dryer closet? We do not have a W/D but we did purchase a 6 CuFt freezer. I would like to put the freezer in the W/D closet. I am not concerned with defrosting while on the road but I would need power when set up in a campground. Will the freezer get power even though we are hooked into 30 AMP service or is the 20 AMP leg dead?

In order to keep this thread short and to keep me from having to read replys that say "I think..","I'm not sure but.." and etc PLEASE only reply if you actually know the answer.

NCFischers · 05-01-2009, 12:53 AM

Glenn,
You will get power to everything with 30 amp power. Just be careful not to run both AC's at the same time. If you do overload the 30 amp power, all that will happen is you will trip the main circuit breaker either in the Monty or at the pedestal. No harm, no foul. That's what they are designed to do. The freezer should be no problem.

exav8tr · 05-01-2009, 01:08 AM

Glenn, I have a small refer/freezer in that compartment and when on 30 amp it still runs.

Glenn and Lorraine · 05-01-2009, 01:34 AM

Thanks very much. This is what I thought but I wasn't sure and I didn't feel like busting my hump getting that freezer in the closet to find it wouldn't work.
Thanks again!!!

Waynem · 05-01-2009, 02:50 AM

Glenn,
When I first got my 3400RL all I had at the stick house was 110V 20Amp. I had an dog bone from 50A to 115V male. When plugged in I had power everywhere. I just could not run the coffee pot in the house on the same circuit, and the AC at the same time. Many a day while getting ready to leave or when we came back from a trip I would run AC, Refrigerator, and TV without tripping the breaker. If DW plugged in the vacuum at the same time it would trip the 20 amp breaker.

If wired correctly you should have power off of 30A at all receptacles.

MuddyPaws · 05-12-2009, 07:43 AM

I had a weird problem with 30A a while back.

My house has been heavily modified by it's previous owner (an engineer!). I found that almost all of the plugs he put in had the neutral and ground wires switched. They 'kinda-sorta' work this way but it's not safe. He did a bunch of other stupid stuff that I've spent years un-doing, but don't get me started.

When I plugged in the Monty, via a dogbone 30A-50A adapter it would blow the breaker in the house. I wasted several hours checking the Monty for shorts.

If this happens to you get a $2.00 plug tester and check your house plugs first.

NCFischers · 05-12-2009, 07:51 AM

I've spent 40 years in the electrical trades. I've seen more things hosed up by engineers than I can count. I believe that no one should be given an engineering degree in ANY field unless they spend two years in the trade they intend to engineer. My apologies to all you engineers out there but I'm speaking from experience.

BB_TX · 05-12-2009, 04:26 PM

Quote:

quote:Originally posted by NCFischers

I've spent 40 years in the electrical trades. I've seen more things hosed up by engineers than I can count. I believe that no one should be given an engineering degree in ANY field unless they spend two years in the trade they intend to engineer. My apologies to all you engineers out there but I'm speaking from experience.

Hey! I resemble that remark.

Actually I am an electrical engineer. Worked for a controls company for 35 years designing safety control systems for power plants before retiring last year. The systems test personnel had a common saying for the engineering group, "There is nothing more dangerous than an engineer with a soldering iron!"

Art-n-Marge · 05-13-2009, 08:38 AM

First about Glenn's power concern, the (30a, 50a, 15/20a) input power goes to the trailer's power distribution supply and then enables the 110v & 12v needs of the trailer outlets, so when Glenn plugs into a 30 amp source all outlets and connections now get power. That's the good news.

The only concern should be how much power is needed at the SAME time. I have read so much and calculated that two Air Conditioners would not be supported by a 30 amp source concurrently so will never try, especially if the fridge is on. But adding a freezer (check the running/starting specs) could put more concurrent demand on the rig when running at 30 amps. You could run the fridge on propane which means the freezer uses what the fridge would have, but doing the math should get you close for your chances.

There is no yes/no answer for this because all combinations of components and their specs will vary. But your yes/no question about the 30amp providing power at the outlet is a YES. Whether it runs will depend on what you calculate.

I was an engineer for over 30 years, but a test engineer for computer products. I chuckle whenever I hear that some engineer did something and everyone thinks it must have been done right. Please realize I made an outstanding living being a test engineer that found that the design engineers screwed up all the time with their designs and implementations. Yes, I'll admit with our educations and experience we've had to become pretty smart about things, but don't give them too much credit. Think of them like doctors, because not every doctor knows everything about everything needing doctoring - I do NOT want my proctologist to operate on my spine (well, maybe the very low part of the spine next to my butt). You get the idea.

Come on Bill (BB TX), fess up... Just because you are a very wise electrical engineer how many things did you work on that created "smoke"? My nose was so good that when there was smoke, I was the one used as the bloodhound that would find the exact component in the exact device in the exact cabinet in the exact location of the 25,000 sq ft of lab.

Glenn, please status us on your project. That sounds like a great idea for Full/Long timing as long as the rig can take the weight. (btw - you give outstanding descriptions of your TV/RV, but what tires do you use on your RV?)

jjackflash · 05-13-2009, 09:41 AM

I've done the same thing as phil for well over a year now. As far as weight goes,I figure I Have a Frig/Freezer in-steaded of a washer/dryer.
Jack

ols1932 · 05-13-2009, 10:48 AM

Every "good" engineer has an "excellent" technician working with him, usually. Seldom have I ever seen an engineer, especially an electrical engineer, working alone. He/she needs that tech.

Orv

BB_TX · 05-13-2009, 11:25 AM

Quote:

quote:Originally posted by ols1932

Every "good" engineer has an "excellent" technician working with him, usually. Seldom have I ever seen an engineer, especially an electrical engineer, working alone. He/she needs that tech.

Orv

OUCH! That hurt.

Dave e Victoria · 05-15-2009, 10:38 AM

What goes around comes around. I've seen bad engineering fixed by good techs and good engineering screwed up by tech. One I still lose sleep thinking about is being on an all night install of an experimental avionics package on a military jet. I needed a break out box to check the install. I had it plugged in and was about to add power when I got to wondering if the breakout box was ever checked out itself. So this engineer got out the old "Simpson" and started buzzing wires. Nothing seemed to make sense. I wondered if this was due to the hour (2:30am) Then it dawned on me. The breakout was for two cables (about 100 pins each) The tech who built it had crossed the cables inside the breakout. I often wonder what would have happened had I ad complete trust in the tech. The point is not to point fingers at techs or engineers but to remind us this is a team effort that depends on a rational level of trust and skepticism on BOTH sides.

ARJ · 05-15-2009, 12:13 PM

Computer techs NEVER screw up!! It was always those damn software guys.

MuddyPaws · 05-15-2009, 03:27 PM

As a long time software guy I take exception to that.

Art-n-Marge · 05-15-2009, 05:19 PM

Okay if we're gonna digress Glenn's topic to nerdness hear this:

How many test engineers does it take to change a lightbulb?.... None, we just report the room is dark.
How many software engineers does it take to change a lightbulb?... None, it's a hardware problem.
How many hardware engineers does it take to change a lightbulb?... None, it's a technician's job.
How many technician's does it take to change a lightbulb? .... Five, one to hold the bulb and four to spin the ladder.

So Glenn, are you sure you want our advice? We spell it W-I-S-D-U-M-B.

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