They called it a power surge....... - Page 2

Paul M · 03-07-2015, 01:22 PM

Please explain why.

glen1971 · 03-07-2015, 01:24 PM

Quote:

Originally Posted by Paul M

ALL 50 Amp RV sources ARE 220 Volt. Thae fact is that the RV does NOT use 220 volt. The Busses in the distribution box are split, so each side gets 110 Volt. For this reason is why some people state that RV's are ONLY 110 Volt. So just for clarification, There IS 220 Volts coming into the RV but it is not utlized in that fashion.

Not to nit pick, but it's actually 120 and 240 volt... 110 volts stems from Edison's original DC distribution system, the last one of which was disconnected in November 2007...

Paul M · 03-07-2015, 01:27 PM

Fair enough. But it may depend on who's system your on and what they have the AVC's set at.

OldCoot · 03-07-2015, 01:30 PM

Quote:

Originally Posted by Paul M

Please explain why.

Why does a 240V 50A service fry a 50 rv plug? BombDoc and a lot of others have fried theirs by plugging into a 50A 250V receptacle like for a welder.

geotex1 · 03-07-2015, 01:30 PM

NEMA 14-50R is wired the same (split phase) regardless of RV or residential use. In residential, it is actually the common receptacle for an electric range.

glen1971 · 03-07-2015, 01:31 PM

Quote:

Originally Posted by Paul M

Fair enough. But it may depend on who's system your on and what they have the AVC's set at.

What is an AVC?

Paul M · 03-07-2015, 01:39 PM

Can't answer about bombdoc's situation ect. without seeing the wiring configuration. The fact of the matter is a multimeter does not lie. If you measure the voltage as described above you WILL get the results as shown above if the source is wired properly. If you notice at campground power pedistals there is a single pole breaker for the 15 / 20 amp receptacle amd a single pole for the 30 amp. But there is a double pole for the 50. Thus the two seperate legs / polarity's which make up the 220 / 240.

geotex1 · 03-07-2015, 01:41 PM

Quote:

Originally Posted by OldCoot

Why does a 240V 50A service fry a 50 rv plug? BombDoc and a lot of others have fried theirs by plugging into a 50A 250V receptacle like for a welder.

Getting way off topic, but anyone with a welder on residential service is wired the same way - split phase with two 120V hot legs.

Their problem with their RV service was an open neutral or ground so guess what happens on the return path - you get 220 surging/backfeeding the intact ground or neutral!

Conversely, you very much can mis-wire a 30A.

Paul M · 03-07-2015, 01:43 PM

AVC' are used in the power company's substations on the distribution transformers. Stands for Automatic Voltage Control. They control the operation of transformer tap changers, which move in response to system load. On heavy load days in the summer when supply's are limited a power authority may invoke a 5% voltage reduction, which helps the reactive resources on the system maintain levels. This is done by moving the settings on the AVC's.

Paul M · 03-07-2015, 01:46 PM

I do apoligize for getting off topic.
Back to the regularly scheduled program.
I would keep the appliances for parts. Better to be looking at it than for it.

Paul M · 03-07-2015, 02:03 PM

Quote:

Originally Posted by fonzie

This is being done just before brown out occurs or load shedding occurs to reduce load on the system.

I believe it more of a resource to maintain the high voltage transmission system voltages within limits to prevent a voltage colaspe, which would lead to cascading outages. Lets face it, if the transmission system is not stable and starts to fail none of the rest of it matters.

Witch Doctor · 03-07-2015, 02:04 PM

Quote:

Originally Posted by Paul M

AVC' are used in the power company's substations on the distribution transformers. Stands for Automatic Voltage Control. They control the operation of transformer tap changers, which move in response to system load. On heavy load days in the summer when supply's are limited a power authority may invoke a 5% voltage reduction, which helps the reactive resources on the system maintain levels. This is done by moving the settings on the AVC's.

This is why most if not all appliances have a plus or minus 10% built in to there equipment voltage requirement such as A/C compressors and such. Before you would get any low voltage or high voltage damage to the equipment. ...

glen1971 · 03-07-2015, 02:14 PM

Quote:

Originally Posted by Paul M

AVC' are used in the power company's substations on the distribution transformers. Stands for Automatic Voltage Control. They control the operation of transformer tap changers, which move in response to system load. On heavy load days in the summer when supply's are limited a power authority may invoke a 5% voltage reduction, which helps the reactive resources on the system maintain levels. This is done by moving the settings on the AVC's.

The nominal voltages are still 120/240 though... Typically, in the United States, the Utility is regulated to provide a voltage of 104.4-127.2 vac (120 volts -13% and +6%).. As the tap changer would be located in the substation, it would only effect the subs buss voltage, and they don't measure the end user voltage and are meant more for larger adjustments. Usually by switching capacitor banks and the use of voltage regulators on the utility side the distribution voltages are changed, but still within regulated tolerances.. It's a delicate balance so that the two aren't fighting each other, as you said earlier to avoid the collapse of a power grid..

Rvdixie · 03-07-2015, 02:15 PM

These are not warranty items so a return to the manufacturer is not in play.

meganjoe · 03-07-2015, 02:20 PM

Quote:

Originally Posted by OldCoot

Pardon me, but I don't believe that is correct.

50 amp rv's are set up for 120/240 which means it needs a neutral.

A 50 amp welding outlet is 240 only (no neutral)

I believe when you use a 30 to 50 adapter it sends the single 30 amp leg (120 ) to both legs in the camper so everything will work , you just can't use everything at the same time..

Joe

geotex1 · 03-07-2015, 02:20 PM

Quote:

Originally Posted by gljurczyk

This is why most if not all appliances have a plus or minus 10% built in to there equipment voltage requirement such as A/C compressors and such. Before you would get any low voltage or high voltage damage to the equipment. ...

Yes sir!

Two pieces of advice for the OP after everything is repaired: 1) never, ever plug your rig into the pedestal - even a home one (!) - with the breaker on because the hot legs can make contact before both the ground and neutral do and the bad things happen (!); and, 2) get a Progressive Industries EMS-HW50C installed as soon as you can afford and not worry about things! You really don't want just a a surge protector, you want the voltage protection as well because as just quoted above around supply is not constant, and can dip or spike beyond the margin.

Paul M · 03-07-2015, 02:24 PM

[QUOTE=glen1971;800647]The nominal voltages are still 120/240 though... Typically, in the United States, the Utility is regulated to provide a voltage of 104.4-127.2 vac (120 volts -13% and +6%).. As the tap changer would be located in the substation, it would only effect the subs buss voltage, and they don't measure the end user voltage and are meant more for larger adjustments. Usually by switching capacitor banks and the use of voltage regulators on the utility side the distribution voltages are changed, but still within regulated tolerances.. It's a delicate balance so that the two aren't fighting each other, as you said earlier to avoid the collapse of a power grid..[/QUOTE I agree with all of the above except that cap banks tend to raise the distribution volatge, thus making the tap lower. this is how the caps support the transmission voltage. Tends to force vars up the trans or at least minimize losses. the only plase a cap may help dist. voltage is at the end of a long dist. circuit. As we know Vars don't travel well.

geotex1 · 03-07-2015, 02:31 PM

Quote:

Originally Posted by meganjoe

50 amp rv's are set up for 120/240 which means it needs a neutral.

A 50 amp welding outlet is 240 only (no neutral)

I believe when you use a 30 to 50 adapter it sends the single 30 amp leg (120 ) to both legs in the camper so everything will work , you just can't use everything at the same time..

Joe

You got it Joe. And a 240/50A welder would use a NEMA 6-50R 3 prong.

I'm pretty sure we geeks are confusing everyone now!

Paul M · 03-07-2015, 02:34 PM

geotex1, Who you calling a geek ? lol

**ependydad** · 03-07-2015, 02:43 PM

Quote:

Originally Posted by meganjoe

50 amp rv's are set up for 120/240 which means it needs a neutral.

A 50 amp welding outlet is 240 only (no neutral)

I believe when you use a 30 to 50 adapter it sends the single 30 amp leg (120 ) to both legs in the camper so everything will work , you just can't use everything at the same time..

Joe

Thanks, Joe. That confirms what I thought I was reading.

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