There was some discussion in another thread about the dangers of campground electrical hookups. I have one of those plug-in circuit testers with three lights that, in theory, let you know if the wiring is okay, reversed, missing a ground, etc. I leave it plugged in all the time in a very visible place. I realize that it does not show if there is a voltage problem. Other than that, are these adequate to make sure things are acceptable?
I would think that there is some benefit in leaving this device plugged in, but it is going to be limited in what it can do for you.
From the way I read your comments, you leave the device plugged in to a normal outlet on the interior of your bus. The problem I see is that certain campground wiring issues could do their damage at the instant the bus gets plugged into the campground box. By the time you plug in and take one step toward the bus door, it is too late. It would be much better to test the box before plugging the bus in.
I created a special outlet to plug the testers in. Its after where the cord plugs into the bus, but before the switch that disconnects all power from the cord to the bus. So I can plug in, then test prior to turning on any power to the bus.
This type of tester will alert you to the most egregious sorts of problems, but only, as already said, if you use it before plugging in your bus.
For a 15- or 20-amp receptacle, these work as-is. To check a 30-amp campground receptacle, you can use a standard 30-to-20 adapter, available at Camping World and elsewhere. For 50-amp, things get a bit more complicated.
Off-the shelf 50-to-30 adapters only pass through one leg of power. In order to test both legs, you will need to make an adapter with a 50-amp "range" plug on one end, and a pair of 20-amp receptacles on the other. Test each side individually -- if you plug two testers into the outlets at the same time, you may get a false positive.
An inexpensive but perfectly adequate voltmeter is about ten bucks. The parts to make an adapter for testing a 50-amp service with your little tester is about double that.
I use the tester on 120v circuits, and my voltmeter on 240/120 circuits (although I also have the adapter, for other reasons).
HTH,
-Sean
http://OurOdyssey.BlogSpot.com
I purchased a small "wall wart" looking thing several years ago (I think I got it at Camping World). It has an LED readout and shows AC voltage and Frequency. Before we installed our EMS power management system, we used to leave this "wall wart" plugged into an outlet that was easily visible. Jack
PS: We still check the power supply we are plugging into with the little 3 light thingy before plugging in the coach. Jack
I don't know if they are any good or not but I use Power Pal before plugging in it talks to you.Plug it into the outlet it reads the circuit checking for grounds and voltage and tells you if it safe to plug into http://www.got50amps.com
good luck
Hi Lin,
This will give you a good idea how to use a meter to test park power.
Also available here:
http://www.busconversions.com/bbs/index.php?topic=5097.0
Nick-
I got up one morning while at the Flagstaff KOA cold as heck to switch propane tanks. When I open the baggage door and knelt on the wet ground I got a pretty good zap. I could feel current flowing through me. At first I blamed it on the parks power box but further investigation revealed a bad power outlet in my engine compartment. The sockets had fused together and shorted making me the ground wire. I am not much of an electrician but after installing a new outlet no more problem.
Quote from: Airbag on March 06, 2009, 07:22:46 PM
I got up one morning while at the Flagstaff KOA cold as heck to switch propane tanks. When I open the baggage door and knelt on the wet ground I got a pretty good zap. I could feel current flowing through me. At first I blamed it on the parks power box but further investigation revealed a bad power outlet in my engine compartment. The sockets had fused together and shorted making me the ground wire. I am not much of an electrician but after installing a new outlet no more problem.
You can still blame the park or your own bus wiring. IF the park outlet was properly grounded AND IF the ground wire from the park outlet was properly connected to the bus frame, you should not have received a shock. In fact, the it should have tripped the park circuit breaker.
Quote from: Len Silva on March 07, 2009, 06:24:16 AM
You can still blame the park or your own bus wiring. IF the park outlet was properly grounded AND IF the ground wire from the park outlet was properly connected to the bus frame, you should not have received a shock. In fact, the it should have tripped the park circuit breaker.
Or maybe I would have been killed? I don't know The KOA equipment looked pretty new but who knows. I know the wiring in my bus is old.
Quote from: Len Silva on March 07, 2009, 06:24:16 AM
You can still blame the park or your own bus wiring. IF the park outlet was properly grounded AND IF the ground wire from the park outlet was properly connected to the bus frame, you should not have received a shock. In fact, the it should have tripped the park circuit breaker.
Not necessarily, unless the park breaker was a GFCI (uncommon on anything larger than a 20-amp service). If there is a ground-to-neutral short in the coach, fully half or more of the entire coach's neutral return current will flow through the ground system, including the coach body. And if the ground, neutral, or both going from the coach to the pedestal is in any way compromised (disconnected, poor connection, undersized wires, etc.) there is a chance that some of that return current will choose to go to ground through another path, such as a person touching the coach.
The only way the pedestal breaker will trip is if the hot side of the system draws more than the handle rating of the breaker -- 30 or 50 amps. If you had that much current flowing through you, you'd be dead. Pedestal breakers are completely insensitive to ground-neutral faults, unless, as I said, it's a GFCI breaker. If the melted outlet resulted in a hot-to-neutral or hot-to-ground short, then, yes, either the pedestal breaker or branch circuit breaker should have tripped, but not otherwise.
This is one of the reasons why I am constantly harping on electrical safety here, including proper bonding (and un-bonding) of the ground and neutral inside the coach.
-Sean
http://OurOdyssey.BlogSpot.com
Ok I will say it...
The pedestal "must" have a separate ground rod. (Not tied to neutral!)
Midwest Electric states that a separate ground is required for any of their panels and equipment right on the label. (they make most of the pedestal panels).
If some idiot used the neutral/ground bond method, Anyone elses hookup could feed power back to the "ground" lug. Not necessarily your wiring.
Part of the problem is that a "lot?" of supposed electricians are unaware about separate grounding requirements mainly because most commercial building and residential panels use the bonded neutral method.
It's and RV thing... Always a separate ground.. ( I have actually carried a copper plated ground rod and stuck it in the ground to be sure. )
Then measured for a voltage between my test rod and the coach chassis. ( Eyebrows get raised too!! ) ::)
Quote from: DrDave-Reloaded on March 07, 2009, 04:00:08 PM
...
The pedestal "must" have a separate ground rod. (Not tied to neutral!)
...
If some idiot used the neutral/ground bond method, Anyone elses hookup could feed power back to the "ground" lug. Not necessarily your wiring.
Part of the problem is that a "lot?" of supposed electricians are unaware about separate grounding requirements mainly because most commercial building and residential panels use the bonded neutral method.
Just to be clear, Dave, the neutral and ground
will be bonded at the first point downstream of the transformer, or at the main panel (for the campground) at the point of entry. That's a NEC requirement, which is separate and distinct from any additional grounding that might be done at the pedestal.
If the neutral is not tied to the ground at the transformer or main panel, there is no way for fault current to return and trip the breaker.
The code, BTW, calls the neutral the "ground
ed conductor" (not to be confused with the "groundi
ng conductor", which is the safety ground).
-Sean
http://OurOdyssey.BlogSpot.com