Plugging in to shore power

[charles boyd]

Sir, I prefer to plug our 30 amp Crestmont in a 30 amp outlet while I prefer to plug our 50 amp Eleganza II in a 50 amp outlet.

> Whats better....plugging into a 50amp outlet with an adaptor to 30amps or plugging into the 30amp outlet directly with a 30amp coach.
>
> Curious to see what people hsve found if the 50amp with 30 adapter is better or 30amp direct puts out better power at sites.

--
C. Boyd
76 Crestmont
East Tennessee

 

[d c *mac* macdonald]

All of the 240V is in the same phase. Therefore, the two 120V halves are the same phase. It's just that the neutral is at the zero volt crossing center and instantaneous voltages are in opposite polarity.

Multi-phase voltages (three-phase power) has voltages that are 120 degrees or 240 degrees (depending upon which phases are being referenced) out of phase with the other two phases.

D C "Mac" Macdonald​
Amateur Radio K2GKK​
Since 30 November '53​
USAF and FAA, Retired​
Member GMCMI & Classics​
Oklahoma City, OK​
"The Money Pit"​
TZE166V101966​
'76 ex-Palm Beach​
k2gkk + hotmail dot com
________________________________
From: Gmclist on behalf of Hal StClair via Gmclist
Sent: Wednesday, January 15, 2020 18:33
To: gmclist
Cc: Hal StClair
Subject: Re: [GMCnet] Plugging in to shore power

> Hal, I will enter the fray here.
>
> The current on the neutral conductor will be the difference of the two hot conductors, not the sum. So if you had 25 amps on each of the hot
> conductors, the current on the neutral would be ZERO amps. If you had 25 on one and 20 on the other, then the current on the neutral would be 5
> amps.
>
> Respectively,
>
> Ken B.

True only if they are on different phases. When people start using 50/30 adapters loads imposed on the neutral can get out of wack depending on how
the rest of the system is wired.
Hal
--
1977 Royale 101348,

1977 Royale 101586, Diesel powered,

1975 Eleganza II, 101230,

1974 Eagle Bus 45',w/slideout,

Rio Rancho, NM

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[d c *mac* macdonald]

A 50 Amp, 125-0-125 Volt EXTENSION cable will work just fine. It's just made with a bit thicker conductors than a 40 Amp (stock) cable and a bit harder to handle/store.

D C "Mac" Macdonald​
Amateur Radio K2GKK​
Since 30 November '53​
USAF and FAA, Retired​
Member GMCMI & Classics​
Oklahoma City, OK​
"The Money Pit"​
TZE166V101966​
'76 ex-Palm Beach​
k2gkk + hotmail dot com

________________________________
From: Gmclist on behalf of James Hupy via Gmclist
Sent: Wednesday, January 15, 2020 17:47
To: gmclist
Cc: James Hupy
Subject: Re: [GMCnet] Plugging in to shore power

Both parts books that I have, as well as the 1975-76 and 77-78 Maintence
manuals all refer to the cord set as 40 AMPERE. I could not find any
reference to a 50 amp cord set in any of my stuff including the idiots
guide. So, it can't be proved beyond a shadow of a doubt by anything that I
have. If you have a 50 amp service in your coach, ONE POSSIBILITY MIGHT BE
that it has been upgraded somewhere during its 40 year existence.
Jim Hupy
Salem, Oregon

On Wed, Jan 15, 2020, 3:26 PM Adolph Santorine via Gmclist <

> Emery
>
> No illusions here - my coach has a 30 amp cord (10 gauge) that was
> installed by the PO
>
> That combined with the 40 amp breakers and the 6 kW generator just didn’t
> add up.
>
> Bill Helmouth and the parts book confirm that the 50 amp cord was the only
> thing GM shipped.
>
> Dolph Santorine
>
> DE AD0LF
>
> Wheeling, West Virginia
>
> 1977 ex-Palm Beach TZE167V100820
> Howell EFI/EBL , Reaction Arms, Manny Transmission
>
>
> > On Jan 15, 2020, at 4:00 PM, Emery Stora via Gmclist <

> >
> > Actually they didn’t. Many people, including you, assume that they have
> a 50 amp cord but look at your cord and you’ll see that it is marked 40
> amps.
> > The plug is the same as a 50 amp but the 40 amp cord matches the two 20
> amp breakers in the box.
> >
> > Emery Stora
> > 77 Kingsley
> > Frederick CO
> >
> >> On Jan 15, 2020, at 12:22 PM, Dolph Santorine via Gmclist <

> >>
> >> The fact that GMC only ever shipped coaches with 50 amp cords is not a
> well known.
> >>
> >> Check the parts book.
> >>
> >>
> >> Dolph
> >>
> >> DE AD0LF
> >>
> >> Wheeling, West Virginia
> >>
> >> 1977 26’ ex-PalmBeach
> >> Howell EFI & EBL, Reaction Arms, Manny Transmission
> >>
> >> “The Aluminum and Fiberglass Mistress"
> >>
> >>>> On Jan 15, 2020, at 10:50 AM, John R. Lebetski via Gmclist <

> >>>
> >>> We were. But to truly understand the reasons "why" , you really need a
> full understanding of the system. I assume he has a TT-30 non GMC upfit
> system.
> >>> So-- if you have an 14-50P to TT-30 adapter at the post, you have the
> potential of overheating the TT-30 cord set, should a fault occur.
> >>> --
> >>> John Lebetski
> >>> Woodstock, IL
> >>> 77 Eleganza II
> >>>
> >>>
> >>> _______________________________________________
> >>> GMCnet mailing list
> >>> Unsubscribe or Change List Options:
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> >>
> >> _______________________________________________
> >> GMCnet mailing list
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> >
> >
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>
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[adolph santorine]

Emery:

I learn something new every day.

25 foot 40 amp cord

What’s interesting is that it has the 50 amp plug on the end.

Which opens the question, what’s the gauge of the wire?

That makes the wiring from the Onan to the jack behind the “Door-Water and Electric” make sense.

Yes, I was multi tasking and since I have a Helmore and a Helmouth in my address book (two completely different characters), it chose the wrong one.

Dolph

DE AD0LF

Wheeling, West Virginia

1977 26’ ex-PalmBeach
Howell EFI & EBL, Reaction Arms, Manny Transmission

“The Aluminum and Fiberglass Mistress"

>
> I checked the Parts book 78Z and it clearly refers to a 40 amp cord. It doesn’t show a 50 amp cord. I can provide the page number in the parts book if you need it.
> It looks like Bill Helmouth (could that have been Bill Helmore) gave you incorrect information.
>
> Since your prior owner replace your cord with a 30 amp you can’t look at the original cord but it clearly is embossed with 40 amp all along the rubber covering of the cord. That is what GM put on all of the factory built motorhomes.
>
> Emery Stora
>

>>
>> Emery
>>
>> No illusions here - my coach has a 30 amp cord (10 gauge) that was installed by the PO
>>
>> That combined with the 40 amp breakers and the 6 kW generator just didn’t add up.
>>
>> Bill Helmouth and the parts book confirm that the 50 amp cord was the only thing GM shipped.
>>
>> Dolph Santorine
>>
>> DE AD0LF
>>
>> Wheeling, West Virginia
>>
>> 1977 ex-Palm Beach TZE167V100820
>> Howell EFI/EBL , Reaction Arms, Manny Transmission
>>
>>

>>>
>>> Actually they didn’t. Many people, including you, assume that they have a 50 amp cord but look at your cord and you’ll see that it is marked 40 amps.
>>> The plug is the same as a 50 amp but the 40 amp cord matches the two 20 amp breakers in the box.
>>>
>>> Emery Stora
>>> 77 Kingsley
>>> Frederick CO
>>>

>>>>
>>>> The fact that GMC only ever shipped coaches with 50 amp cords is not a well known.
>>>>
>>>> Check the parts book.
>>>>
>>>>
>>>> Dolph
>>>>
>>>> DE AD0LF
>>>>
>>>> Wheeling, West Virginia
>>>>
>>>> 1977 26’ ex-PalmBeach
>>>> Howell EFI & EBL, Reaction Arms, Manny Transmission
>>>>
>>>> “The Aluminum and Fiberglass Mistress"
>>>>

>>>>>
>>>>> We were. But to truly understand the reasons "why" , you really need a full understanding of the system. I assume he has a TT-30 non GMC upfit system.
>>>>> So-- if you have an 14-50P to TT-30 adapter at the post, you have the potential of overheating the TT-30 cord set, should a fault occur.
>>>>> --
>>>>> John Lebetski
>>>>> Woodstock, IL
>>>>> 77 Eleganza II
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> GMCnet mailing list
>>>>> Unsubscribe or Change List Options:
>>>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>>>
>>>> _______________________________________________
>>>> GMCnet mailing list
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>>>
>>>
>>> _______________________________________________
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>>
>>
>> _______________________________________________
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>
>
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[Fred Hudspeth]

My TZE...1335, a "late" '78 Royale has the OEM 50 AMP cord installed by the
upfitter, Coachmen. Emery is correct in that it is really 40amp service but
plugged into 50 amp supply. I use a 30 amp adapter when 50 amp "plug-in" is
not available. Both the "50" and 30 amp services have worked flawlessly in
my 26 years ownership.

Fred Hudspeth


Fred Hudspeth
1978 Royale (TZE 368V101335) - Tyler, TX
1982 Airstream Excella (motorhome) - Cooper Landing, Alaska

 

[Melbo]

Isn't electricity fun?

If properly wired it should be as Ken says.

If not done properly you could end up with what Hal says.

Most of the "newer" pedestals seem to be wired correctly and I personally have not had issues. In older parks or Mexico I never trust them and
typically check with a meter before connecting. If I get zero volts across the two hots on a 50 amp receptacle and 120 volts on each leg to ground I
severely limit my electrical use just to be safe.

Just My Way.

HTH

Melbo
--
Albuquerque NM Bus Conversion 1978 MCI 1973 GMC

 

[john r. lebetski]

Besides all the other reasons listed, the more adaptors you add, the more Voltage drop you get, if the connectors are warm, you are losing Voltage.
At some point it's like Clark Griswald in Christmas Vacation
--
John Lebetski
Woodstock, IL
77 Eleganza II

 

[Matt Colie]

> Hal, I will enter the fray here.
> The current on the neutral conductor will be the difference of the two hot conductors, not the sum. So if you had 25 amps on each of the hot
> conductors, the current on the neutral would be ZERO amps. If you had 25 on one and 20 on the other, then the current on the neutral would be 5
> amps.
> Respectively,
> Ken B.

> True only if they are on different phases. When people start using 50/30 adapters loads imposed on the neutral can get out of wack depending on
> how the rest of the system is wired.
> Hal

Hal,

There is a severe nomenclature problem here.
For a 14-50 receptacle to be approved, the two hot (L1,L2) have to be the opposite ends of the same phase. This makes those two 180° out of phase.
This is colloquially described in the trade (was mine once) as the "other side of the phase". Then we get to Y vs Delta vs Star (Multi-phase not seen
shore-side).
If they were one leg on another phase, it would not be 240-120/120 because the legs would not not be 180° out, but leading or lagging by 120°. That
is when you see numbers like 208, 168 & 86 Volts and now the guy that had to fix it has to try to find out what got done where and get the power back
where the Chief wants it.

If someone were to connect a 14-50 as you suggest, yes, the neutral would be at risk. But, I do believe that in the USA and Canada most of that stuff
is inspected. If a GMC owner does not carry a meter, he should get one at Hazard Fright for cheap. Most other 50 amp coaches that I have seen have
safety systems or power protection devices that would warn the owners of this case.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

 

[Ken B]

One of the things I always do is check the connector(s) with my hand to see if any are getting warm. I do this after 5 or 10 minutes of running the
coach and again a hour or two later.

Where there is heat there is a poor connection or an undersized wire. I also keep a 3 light tester inside. I just leave it plugged in all the time.
Usually in the kitchen plug.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

 

[john r. lebetski]

Since Matt got into the nuts and bolts of 14-50, there is one more "odd" condition to be aware of. If the neutral has a poor connection, your Voltage
on the lighter loaded leg can swing ABOVE the 125V mark. This is because the lack of neutral connections allows the one phase to reference the other
approaching the 240V present.
--
John Lebetski
Woodstock, IL
77 Eleganza II

 

[Jim Hupy]

Loose connections in motorhome electrical shore power connectors, breakers,
corroded terminals, etc. are a real problem, particularly in coastal areas
that have salt air and constant rain. Corrosion inhibitors do a good job if
used frequently. Tighten the connecting screws, conductor lugs, all the
screws around the generator compartment connections, etc. I do mine once a
year or so. Electricity, if allowed to do so, will seek the easiest pathway
to ground. If that is through YOU, that is the way it will go.
Jim Hupy
Salem, Oregon

On Fri, Jan 17, 2020, 10:00 AM John R. Lebetski via Gmclist <

> Since Matt got into the nuts and bolts of 14-50, there is one more "odd"
> condition to be aware of. If the neutral has a poor connection, your Voltage
> on the lighter loaded leg can swing ABOVE the 125V mark. This is because
> the lack of neutral connections allows the one phase to reference the other
> approaching the 240V present.
> --
> John Lebetski
> Woodstock, IL
> 77 Eleganza II
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[richshoop]

One thing about the shore power cord. If the plug gets damaged, replace the cord, do not "save some money" on a replacement plug. It will not provide the reliable, safe connection, you expect. Also, the room inside the plug body that is needed to make those connections, is a perfect place for water to stay trapped. Guess how I learned!

>
>
> One of the things I always do is check the connector(s) with my hand to see if any are getting warm. I do this after 5 or 10 minutes of running the
> coach and again a hour or two later.
>
> Where there is heat there is a poor connection or an undersized wire. I also keep a 3 light tester inside. I just leave it plugged in all the time.
> Usually in the kitchen plug.
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

 

[Ken H.]

Richard,

I can't agree with your condemnation of replacement plugs. I've been
replacing them on my GMC for 20 years and on a wide variety of other RVs
for 40 years before that. I've NEVER had a problem with "trapped" water.
Now, I do admit that I am careful to plug into sheltered sockets and if I
have to plug into an unsheltered extension cord, I protect the junction
with an inverted bucket, a tied-around plastic shield, or other simple
water deflector. And I HAVE quit using the "old fashioned"
bakelite-enclosed plugs because I got tired of them shattering every time I
dropped one on a hard surface. Since I began using yellow plastic ones
from Camco and others, even that problem has gone away.

Feel free to replace your defective plugs with new cords having molded-on
plugs -- but you'll still need to protect those connections from the
impingement of water. I'll keep following the cheaper, successful path
I've chosen. And followed long before I got the MSEE.

Ken H.

On Sat, Jan 18, 2020 at 2:16 PM RICHARD/MARLI SHOOP via Gmclist <

> One thing about the shore power cord. If the plug gets damaged, replace
> the cord, do not "save some money" on a replacement plug. It will not
> provide the reliable, safe connection, you expect. Also, the room inside
> the plug body that is needed to make those connections, is a perfect place
> for water to stay trapped. Guess how I learned!
>
> > On January 17, 2020 at 8:12 AM Ken Burton via Gmclist <

> >
> >
> > One of the things I always do is check the connector(s) with my hand to
> see if any are getting warm. I do this after 5 or 10 minutes of running the
> > coach and again a hour or two later.
> >
> > Where there is heat there is a poor connection or an undersized wire. I
> also keep a 3 light tester inside. I just leave it plugged in all the
> time.
> > Usually in the kitchen plug.
> > --
> > Ken Burton - N9KB
> > 76 Palm Beach
> > Hebron, Indiana
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
> _______________________________________________
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> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[powwerjon]

Ken,
I was going to comment, but you hit all the right answers. The Yellow
Camco's both male and female are great!

J.R. Wright
GMC Great Laker
GMCGL Tech Editor
GMC Eastern States
GMCMHI
TZE Zone Restorations
78 Buskirk Custom 29.5' Stretch
75 Avion (Under going Frame up Restoration)

On Sat, Jan 18, 2020 at 8:53 PM Ken Henderson via Gmclist <

> Richard,
>
> I can't agree with your condemnation of replacement plugs. I've been
> replacing them on my GMC for 20 years and on a wide variety of other RVs
> for 40 years before that. I've NEVER had a problem with "trapped" water.
> Now, I do admit that I am careful to plug into sheltered sockets and if I
> have to plug into an unsheltered extension cord, I protect the junction
> with an inverted bucket, a tied-around plastic shield, or other simple
> water deflector. And I HAVE quit using the "old fashioned"
> bakelite-enclosed plugs because I got tired of them shattering every time I
> dropped one on a hard surface. Since I began using yellow plastic ones
> from Camco and others, even that problem has gone away.
>
> Feel free to replace your defective plugs with new cords having molded-on
> plugs -- but you'll still need to protect those connections from the
> impingement of water. I'll keep following the cheaper, successful path
> I've chosen. And followed long before I got the MSEE.
>
> Ken H.
>
> On Sat, Jan 18, 2020 at 2:16 PM RICHARD/MARLI SHOOP via Gmclist <

>
> > One thing about the shore power cord. If the plug gets damaged, replace
> > the cord, do not "save some money" on a replacement plug. It will not
> > provide the reliable, safe connection, you expect. Also, the room inside
> > the plug body that is needed to make those connections, is a perfect
> place
> > for water to stay trapped. Guess how I learned!
> >
> > > On January 17, 2020 at 8:12 AM Ken Burton via Gmclist <

> > >
> > >
> > > One of the things I always do is check the connector(s) with my hand to
> > see if any are getting warm. I do this after 5 or 10 minutes of running
> the
> > > coach and again a hour or two later.
> > >
> > > Where there is heat there is a poor connection or an undersized wire.
> I
> > also keep a 3 light tester inside. I just leave it plugged in all the
> > time.
> > > Usually in the kitchen plug.
> > > --
> > > Ken Burton - N9KB
> > > 76 Palm Beach
> > > Hebron, Indiana
> > >
> > > _______________________________________________
> > > GMCnet mailing list
> > > Unsubscribe or Change List Options:
> > > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >
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