Home again

[Chuck Wheeler]

When a neutral is lost the current then
flows from one hot leg through what ever is turned on to the neutral then from
neutral through the other leg to the other hot side. One hot to the other
will measure 220-240 vac so you would normally observe 110-120 from one hot
side to neutral. So with a “floating” neural the voltage
divides in proportion to the resistance of the loads. For example it one
side was 100ohms and the other was 50 ohms you would have 73 volts across the
50 ohm load and 147 across the 100 ohm load. This is a simple explanation
as there is impedance, power factors and other things that enter into it with
ac, but it is close. This incorrect voltage for the connected devices is
what causes problems. If you are using a cheater to plug into a 20 amp or
30 amp source the two hot sides are connected together so there is 0 volts
between them, but 110-120vac form either side to the neutral.

- Chuck
Wheeler-

1982 FC 31SB Fort Worth TX

---

From: WanderlodgeForum@yahoogroups.com [mailto:WanderlodgeForum@yahoogroups.com] On Behalf Of gregory O

Sent: Saturday, November 14, 2009
1:09 PM

To: WanderlodgeForum@yahoogroups.com

Subject: [WanderlodgeForum] Re:
Home again

the condition is called lost neutral or open neutral. to call it a common would
imply dc current. I believe???the transfer switch removes the neutral along
with the two hot lines otherwise the shorepower neutral which is earth ground
will ground out all the genset ac current???. if the transfer switch was the
problem that caused the other resulting issues, replacing the resulting issues
and the causing problem (transfer switch) will keep it from happening again. it
may well be that the neutral was lost some other place like in your shore cord
or in the campground pedistal and the issue is doomed to repeat its self again.




I can not understand how the ac current transfers voltage to the other leg when
the neutral is lost but I realize that electrical code properly followed will
prevent the damage.

Here is a rv related lost neutral article

http://www.myrv.us/electric/Pg/open_neutral.htm



One of the gals in our rv club had a recent lost neutral when her plug fell out
of the reseptical on an angle. the ground and center two hot prongs stayed connected.
I can also see where carbon stained prongs on the plug can cause a lost
neutral. I now always make the effort to shut down the breaker prior to
connecting and use duct tape or a copper wire tie (10 ga single strand
irrigation wire)to keep the pedistal connection inplace



Greg 94ptca



--- In "WanderlodgeForum%40yahoogroups.com",
"gpaulcarver" .> wrote:

>

>

> First we'd like to thank all who responded to our distress and

> especially Liz who posted our predicament when we couldn't. Leaving all

> to chance, we departed the last Lone Star Bird rally in balmy Texas to

> venture north to Colorado
to relocate an aging Aunt to a nursing

> facility. That said, the "chance" portion was more than expected
in

> late Oct. Our intended stay was 3-5 days (just before the unscheduled

> weather) and got extended to 14 days to accomplish all that needed done.

> Well the weather added some of those days to correct problems created by

> 15 degree temps. at night and 2 feet of snow making corrections

> difficult in windy Royal Gourge. First our Primus system wasn't working

> properly so basement heat was not on. Subsequently our water pumps

> froze and cracked and the parks water system was turned off for the

> season. Next a heavy snow took out the common on our 50 amp electric

> circut. This caused a chain of events to include frying our shorepower

> transfer switch, the microwave, a TV, one charger, a circut on the

> inverter, and two GFI's. We were ill prepared to address many of the

> issues in the weather and limited tooling let alone no supply source.

> Luckily the zap spared our refrigerator and the other half of the

> transfer switch. So our generator saved the remaining days and provided

> heat till we could drive up to Colorado
Springs to a great shop that

> corrected most of our problems. We'll post later on that shops name and

> address. Needless to say we're glad to be home and express again our

> appreciation for the support offered from this group.

>

> Paul & Jo Carver

>

> '93 pt40 "Teri" Seven Points TX.

>