Checking the 50a/30a service before you plug in? [message #295744] |
Fri, 19 February 2016 14:28 |
rcjordan
Messages: 1913 Registered: October 2012 Location: Elizabeth City, North Car...
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Over at the Daily Pose today
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I have a coach here that had a ...well, AC melt down from a bad plug at an RV park. You really need to check your power coming in before hooking up.
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Jim then posts a pix of a thoroughly fried shore-power cable. (down at the bottom http://www.firefightmarine.com/gmccoop/gmc-friday-but-were-still-on-wednesday/)
I keep a 120v polarity/ground checker plugged in inside the coach but I could easily develop a habit of checking the power pole BEFORE I plug in. I'd prefer a simple plug-in analyzer but to do both 50 and 30 I may have to drag out the multimeter.
http://www.amazon.com/gp/product/B00JGJH8QU
A related question is whether anyone is using surge suppressors? I tend to think that's overkill and can't say I've seen any in use at the rallies I've attended so far.
SOLD 77 Royale Coachmen Side Dry Bath
76 Birchaven Coachmen Side Wet Bath
76 Eleganza
Elizabeth City, NC
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Re: Checking the 50a/30a service before you plug in? [message #295746 is a reply to message #295744] |
Fri, 19 February 2016 15:10 |
lqqkatjon
Messages: 2324 Registered: October 2010 Location: St. Cloud, MN
Karma: 5
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one nice thing about our coaches, not much computer equipment to worry about that expensive surge protectors they sell. If it zaps my flat screen TV, that TV may be cheaper then the surge protector.
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
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Re: [GMCnet] Checking the 50a/30a service before you plug in? [message #295754 is a reply to message #295748] |
Fri, 19 February 2016 16:02 |
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USAussie
Messages: 15912 Registered: July 2007 Location: Sydney, Australia
Karma: 6
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RC,
Who came up with this?
Regards,
Rob M.
The Pedantic Mechanic
-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of RC Jordan
Sent: Saturday, February 20, 2016 8:26 AM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Checking the 50a/30a service before you plug in?
This DIY 50a tester might be in order.
http://www.myrv.us/electric/Pg/tester_50amp.htm
> not much computer equipment to worry about
I agree. Then again, JimB put in a Chinee digital voltmeter on the Royale and in the short time we've been rallying I've seen some
voltage low enough
that I shut down the roof units.
--
77 Royale Coachmen Side Dry Bath
76 Birchaven Coachmen Side Wet Bath
Elizabeth City, NC
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Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
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Re: Checking the 50a/30a service before you plug in? [message #295755 is a reply to message #295744] |
Fri, 19 February 2016 16:12 |
jhbridges
Messages: 8412 Registered: May 2011 Location: Braselton ga
Karma: -74
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Since the Onan feeds both legs in parallel anyway, we care not if the shore plug does so - as long as it's protected to 40 amps total. The two plug-in outlet testers are the move. They will indicate correctly wired outlets whether the feed is parallel or not. Unless your coach is modified to have 220V appliances in it, you don't care either. Personally I'd rather have the analog movement voltmeter (also heathen chinee I suspect) than the cheeep digital ones.. the analog is much less susceptible to outside influence. Park close to an AM antenna farm and you'll likely see what I mean.
--johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
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Re: Checking the 50a/30a service before you plug in? [message #295760 is a reply to message #295744] |
Fri, 19 February 2016 16:24 |
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RF_Burns
Messages: 2277 Registered: June 2008 Location: S. Ontario, Canada
Karma: 3
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If you are working off a 120/240 system, you should put some load on one line to neutral and watch the voltmeter. If the neutral connection is good it will stay at ~120 volts, if its not a good neutral, the voltage across your load will go down and the voltage on the unloaded leg will go way up!! Not good!
A poor neutral connection may still look good on your tester because you have balance loads on each line. You need to put some load onto one line to make the neutral take some current. Plug in your toaster or electric heater, that will put a good load on the connections.
If you are working on a straight 120v circuit if you have a bad neutral (or line) connection, you will just lose power as soon as you place a significant load on the circuit.
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC. 1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
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Re: Checking the 50a/30a service before you plug in? [message #295761 is a reply to message #295744] |
Fri, 19 February 2016 16:28 |
rcjordan
Messages: 1913 Registered: October 2012 Location: Elizabeth City, North Car...
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>Who came up with this?
With parallel feeds like Johnny pointed out, I had thought I might cobble together something for 50a using cheap, plug-in polarity testers. I happened upon that DIY one I linked when I went out searching again. Admittedly, my own design would have forgotten the 240v led indicator. I was hoping for something ready-made, compact, and cheap. Shouldn't be more than $60. No such luck.
30a is easy --stick a plug-in tester into a 30/15 adapter.
SOLD 77 Royale Coachmen Side Dry Bath
76 Birchaven Coachmen Side Wet Bath
76 Eleganza
Elizabeth City, NC
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Re: Checking the 50a/30a service before you plug in? [message #295766 is a reply to message #295744] |
Fri, 19 February 2016 17:18 |
JohnL455
Messages: 4447 Registered: October 2006 Location: Woodstock, IL
Karma: 12
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Bruce summed it up nicely. You can easily over voltage some items on the lighter loaded side and brown out the heavier loaded side if neutral is missing. A good way to burn out rooftops etc. TVs and computers are mostly 90-240 autoswitching nowdays so they probably will survive. Though metering a park post won't always tell you how snug the connections are, I always meter first. Each hot to N. Each hot to G. Hot to hot. N to G.
John Lebetski
Woodstock, IL
77 Eleganza II
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Re: Checking the 50a/30a service before you plug in? [message #295771 is a reply to message #295744] |
Fri, 19 February 2016 17:53 |
rcjordan
Messages: 1913 Registered: October 2012 Location: Elizabeth City, North Car...
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>meter first
>hoping for something ready-made, compact, and cheap
I'm going the meter first route mostly because what I've found ready-made is bulky and pricey. I'll keep an eye on the low voltage issue with JimB's Chinee Multimeter Panel (which we love). If I see much more of this 108-110v from the pedestal, I may consider low-voltage shutoff to save the heat pump compressor. FWIW, here's the least expensive bulky-pricey circuit analyzer I was able to find
http://www.amazon.com/gp/product/B00WED16QS
SOLD 77 Royale Coachmen Side Dry Bath
76 Birchaven Coachmen Side Wet Bath
76 Eleganza
Elizabeth City, NC
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Re: Checking the 50a/30a service before you plug in? [message #295773 is a reply to message #295744] |
Fri, 19 February 2016 18:11 |
kerry pinkerton
Messages: 2565 Registered: July 2012 Location: Harvest, Al
Karma: 15
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I built a 50A pedestal tester at a recent SOB rally I attended. It uses two of the little plug in 120V testers (one for each leg) and also a 120V plug in volt meter. A small 220V green light is jumpered off the each of the hot legs. If the plugs indicate good, the voltage is good on each leg, and the green light is on, everything is fine. If everything is good EXCEPT the green light, the two legs are in phase and do not produce a true 240V system.
Pretty simple thing. I can probably find a schematic if needed.
At the Dixielander rally in Pensacola, my SOB didn't act right power wise. Turned out that one leg of the breaker wasn't connecting and I was running on 30A instead of 50A. The tester would have shown me that before I plugged in the coach.
Kerry Pinkerton - North Alabama
Had 5 over the years. Currently have a '06 Fleetwood Discovery 39L
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Re: [GMCnet] Checking the 50a/30a service before you plug in? [message #295778 is a reply to message #295744] |
Fri, 19 February 2016 18:41 |
Ken Henderson
Messages: 8726 Registered: March 2004 Location: Americus, GA
Karma: 9
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I theoretically agree with Y'All about the importance of
checking/monitoring campground power supplies. And I've got an in-line
surge protector for my 30A X-Birchaven, though I very rarely think to use
it.
BUT, the fact is that I've been RVing, in tent trailers, travel trailers,
and motorhomes, from Key West to Fairbanks, & E. Coast to W. Coast, since
1958 (actually back to 1942, but without much travelling). I have NEVER
had ANY electrical equipment damage from the power source. Call me Lucky,
but with that history behind me, I find it difficult to become very
concerned and devote much energy or funds to "solutions". My worrying's
generally confined to reversed polarities and incorrect grounding.
JWID :-)
Ken H.
On Fri, Feb 19, 2016 at 3:28 PM, RC Jordan wrote:
> Over at the Daily Pose today
> -----
> I have a coach here that had a ...well, AC melt down from a bad plug at an
> RV park. You really need to check your power coming in before hooking up.
> -----
> Jim then posts a pix of a thoroughly fried shore-power cable. (down at the
> bottom
>
> http://www.firefightmarine.com/gmccoop/gmc-friday-but-were-still-on-wednesday/
> )
>
> I keep a 120v polarity/ground checker plugged in inside the coach but I
> could easily develop a habit of checking the power pole BEFORE I plug in.
> I'd
> prefer a simple plug-in analyzer but to do both 50 and 30 I may have to
> drag out the multimeter.
>
> http://www.amazon.com/gp/product/B00JGJH8QU
>
> A related question is whether anyone is using surge suppressors? I tend to
> think that's overkill and can't say I've seen any in use at the rallies
> I've attended so far.
> --
> 77 Royale Coachmen Side Dry Bath
> 76 Birchaven Coachmen Side Wet Bath
> Elizabeth City, NC
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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Re: Checking the 50a/30a service before you plug in? [message #295779 is a reply to message #295744] |
Fri, 19 February 2016 19:08 |
rcjordan
Messages: 1913 Registered: October 2012 Location: Elizabeth City, North Car...
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>worrying's generally confined to reversed polarities and incorrect grounding
Well, other than the fact that we've sold thousands of pedestals over the years and I got to hear the horror stories from the electricians and park maintenance guys, polarity, grounding, and corrosion were my mild concern. ....Then JimB put in that always-on multimeter right beside where I sit to drink my coffee and then I get to watch the voltage drop as the park wakes up. Maybe I'll just disconnect the panel and pretend I've got good line voltage, heh.
Seriously, I think polarity, grounding, and corrosion are the main issue and I'll just keep an eye on the voltage for a while.
SOLD 77 Royale Coachmen Side Dry Bath
76 Birchaven Coachmen Side Wet Bath
76 Eleganza
Elizabeth City, NC
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Re: Checking the 50a/30a service before you plug in? [message #295797 is a reply to message #295746] |
Fri, 19 February 2016 21:10 |
Ken Burton
Messages: 10030 Registered: January 2004 Location: Hebron, Indiana
Karma: 10
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I built one like that once out of a old 50 to 30 amp adapter cable but I used on ONE duplex outlet with two checkers and no meter. Make the mounting box for the duplex outlet plastic. I would hate to be standing out in wet grass and have a hot neutral wired to a steel box.
I loaned it so someone at a rally one time and never got it back. I unfortunately forgot who I loaned it to. You could make one for around $20.00. Mine did not have the meter but one could be easily added. Just plug it in. I would rather meter inside the coach under load rather than outside when there is no load attached.
A 30 amp checker is simple. Just install a 30 to 15 amp adapter to a standard checker.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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Re: Checking the 50a/30a service before you plug in? [message #295812 is a reply to message #295744] |
Sat, 20 February 2016 08:14 |
jhbridges
Messages: 8412 Registered: May 2011 Location: Braselton ga
Karma: -74
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I like Ken's approach. Bust the connecting tabs off the duplex outlet and feed the upper and lower with seperate legs. Plug a pair of neon bulb testers in it. It would indictae ground and polarity problems. We've about a hundred pedestals at one of our show sites, corrosion and loose terminals are the major problems we see.
--johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
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