Community Forums

FlyingDiver · 03-22-2014, 10:25 AM

Quote:

Originally Posted by wb7auk

The neutral and earth ground at the meter as well as at the main panel.

And the meter could be hundreds of feet from the pedestal. Not sure how that helps any.

wb7auk · 03-22-2014, 11:08 AM

Because in the post it stated from the transformer not the main panel.
Voltage drop from the sub panel to the main panel will remain the same
but the loss from the main panel to the transformer depends on how many
neutral returns are present.

TQ60 · 03-22-2014, 03:35 PM

Ground rod or water pipe connection is at meter so often called meter ground.

It is needed there to set reference.

If you have additional ground rods and ground is not that conductive you may have odd performance of ground system so best to avoid considereng one.

If you must do something at a pedistal consider a simple jumper wire with clip to attach to water faucet.

Local code sets rules for secondary grounds.

wa8yxm · 03-22-2014, 05:10 PM

Most of the campgrounds I stay at there is a ground rod driven in right next to the pedestal.. I believe this is required.. And I can understand why.

I like one of the campgrounds I stay at in the winter.. I use the Bob Heil method of grounding my ham gear (Mains ground) and the standard ground rod is 10 feet long,, Driven into the ground till only a couple inches remain above if that... Well I'm perhaps 5 feet above the shore line of the lake and perhaps 10 feet from it horozontialy so I'm sure the water table is .. Well, 5 feet. So the rod is at least five feet into wet earth. Works well.. I get great performance from the radio on those sites.

TQ60 · 03-22-2014, 05:39 PM

That ground rod is for radio and completely different from that of safety ground.

For radio you are establising a reference point for all signals, part of the antenna system for tuning as well as protection from sky based energy that does not have a breaker.

Although in this case with the abundance of water it would likely work fine but consider where the breaker may be in a circuit.

If you short to a distant ground the current path back to the meter ground may not be such that it is high enough to trip the breaker but enough to lite up the chassis of your rv.

Now you have potential for disaster.

If ground rod at pedistal and it is to local code then it is fine.

Likely connected into the pedistal in such a manner to insure proper current path to trip breakers on any ground fault.

wb7auk · 03-22-2014, 05:44 PM

Lets see if I can give some insight:
A high voltage is fed to one input side of the transformer, the cold side of that winding
is neutral and it is also tied to earth ground at the pole.
The load side of the transformer has 2 out of phase outputs and a neutral, this neutral is tied back to the input neutral.
The two out of phase hots and a neutral is fed to the meter where 2 ground rods
6 feet apart are required that connect to the meter box and neutral.
2 hots out of phase with a neutral are fed to one or more main panels.

bilb2765 · 04-11-2014, 04:38 PM

Word of caution.
In a small, out of the way, campground in Florida, they actually wired the 30A for 220vac.
Burned up my mother-in-laws power box. Explained to the owner, (who did pay for the repair), that 30A is 110v, and 50A is 220v. He told me I was wrong, and his electrician knew better. So I went to have a conversation, but nobody was home. For the fun of it, I looked at his power pedestal. It had black burn marks all over it.
Just saying, I look at the pedestals around me before connecting anymore. Also use a wire tester.
My2cents.

wa8yxm · 04-12-2014, 08:29 AM

Quote:

Originally Posted by FlyingDiver

Not in my RV it's not. Nor many other high-end rigs.

In every RV I have even been in there are only two voltages used 120 volt and 12 volt DC.. True the pedistal delivers 120+120=240 volt but all the appliances are 120 volt, this is why I can run just fine on a 30 amp site.

I do understand that it is possible to put in things like 240 volt ranges and cloths dryers and such, but this is avoided in motor homes because you may not be able to get a 50 amp site.

Thus everything is 12 or 120 volt (I ignored the DC system in the earlier post) nothing eats 240 volt with one exception.

IF you have an Energy Manager.. IT uses the 240 volt for one reason.. IF it sees 240 volt (I suspect 200 + will do it) then it "knows" you are on a 50 amp circuit.

The 50 amp RV is just like your house. Power to your house is the same 4 wires on that plug.. L-1, L-2, Neutral and Ground, (The first 3 make up the "Drop" or power line to the house, the ground is provided locally) It is 120/240 volt service, Your TV, Radio, Hair Dryer, Microwave, computer, and most all the lamps in the house are 120 volt.. Central air is 240 volt for the compressor but 120 volt for the blower inside (As is the furnace blower which is of course the same blower) an electric dryer is 240 volt as is an electric water heater and an electric range.. So is electric house heat if it is "Central" in nature.

Space heaters are 120 volt

In the RV, lights, water pump and some other stuff are 12 volt battery power DC, but all the appliances that eat shore power are 120 volt.. UNLESS it is a special order.

FlyingDiver · 04-12-2014, 08:58 AM

Quote:

Originally Posted by wa8yxm

In every RV I have even been in there are only two voltages used 120 volt and 12 volt DC.. True the pedistal delivers 120+120=240 volt but all the appliances are 120 volt, this is why I can run just fine on a 30 amp site.

I do understand that it is possible to put in things like 240 volt ranges and cloths dryers and such, but this is avoided in motor homes because you may not be able to get a 50 amp site.

Thus everything is 12 or 120 volt (I ignored the DC system in the earlier post) nothing eats 240 volt with one exception.

IF you have an Energy Manager.. IT uses the 240 volt for one reason.. IF it sees 240 volt (I suspect 200 + will do it) then it "knows" you are on a 50 amp circuit.

The 50 amp RV is just like your house. Power to your house is the same 4 wires on that plug.. L-1, L-2, Neutral and Ground, (The first 3 make up the "Drop" or power line to the house, the ground is provided locally) It is 120/240 volt service, Your TV, Radio, Hair Dryer, Microwave, computer, and most all the lamps in the house are 120 volt.. Central air is 240 volt for the compressor but 120 volt for the blower inside (As is the furnace blower which is of course the same blower) an electric dryer is 240 volt as is an electric water heater and an electric range.. So is electric house heat if it is "Central" in nature.

Space heaters are 120 volt

In the RV, lights, water pump and some other stuff are 12 volt battery power DC, but all the appliances that eat shore power are 120 volt.. UNLESS it is a special order.

The universe of "RVs you have been in" is obviously incomplete. Go ahead, look at the features of the higher end Newmars, Tiffins, Entegras, etc. Most will have, as either a standard or optional feature, a 240V residential (stackable) dryer. I'll wait...

So the rest of your post is just wrong (except the irrelevant residential wiring comments). I'm not going to go item by item.

And NO, the stackable dryer is not a "special order" for the brands I listed. It's either standard, or a price listed option.

wa8yxm · 04-12-2014, 12:52 PM

The key word in your post is "optional" which I agreed with already

FlyingDiver · 04-12-2014, 12:54 PM

Quote:

Originally Posted by wa8yxm

The key word in your post is "optional" which I agreed with already

Well, that's not what you actually wrote, but whatever....

wa8yxm · 04-12-2014, 06:18 PM

Quote:

Originally Posted by FlyingDiver

Well, that's not what you actually wrote, but whatever....

True I said it was Avoided.. I meant to say Optional or special order.. I do agree there are some out there that are 240 volt. though why You would want that I do not know, since many campsites, (Example where I'm parked) are only 120. And some are doing good to push 25 amp without tripping the breaker.

FlyingDiver · 04-12-2014, 07:12 PM

Quote:

Originally Posted by wa8yxm

True I said it was Avoided.. I meant to say Optional or special order.. I do agree there are some out there that are 240 volt. though why You would want that I do not know, since many campsites, (Example where I'm parked) are only 120. And some are doing good to push 25 amp without tripping the breaker.

To each his own. We don't "camp". We're full-timers who live in our RV, and we choose to spend most of our time at locations that have the services we want. This is a choice that most of the owners at the places we stay most often have also made. 240V appliances are nothing that needs to be "avoided". You just need to decide what's more important - the amenities in your home, or the flexibility on where to stay (long term).

When we do decide to stay at "sub-standard" locations, we use our generator when necessary. That's what it's there for.

jrgreen · 04-12-2014, 08:53 PM

If the 50A RV source is 240v with 240v appliances in the coach, how does this work? or does it? This is straight off of the Progressive Industries web site for their EMS-PT50C:

Accidental 240V Protection:
If 240 volts is detected when plugging into AC power, the EMS will NOT allow power to the RV. If this condition occurs while power is applied to the RV, the EMS shuts off power instantly. The display will read the voltage and E-3 for the error. (NEVER BYPASS THE EMS WHEN THIS OCCURS.)