Can't test 50amp service with this

[marjoa]

Originally Posted by Tha_Rooster

I have no problem sticking my prob in a hot area, if you don't know what you are doing ?

Ok that's funny.

[jrusselltx]

There is a basic flaw in using just a voltmeter to test a circuit prior to energizing it: there is no load connected. The voltmeter can read the correct voltage with any number of problems in the circuit because it essentially uses no current from the power source. You can detect a completely open circuit or a dead circuit, but that's about it.

Any unwanted resistance in the circuit (bad breaker, wire broken almost in two, corroded terminals, etc.) means that the voltage with no load can be correct but it can't produce the correct power. You could carry a load device to put a load on the circuit (something on the order of 15 to 20 Amps) and see how much the voltage dropped but that's not a practical solution. The protection devices test the voltage before applying the load (that is, your RV power circuits) to make sure it is correct and then monitor the voltage to make sure it stays within acceptable limits. Too high of a voltage to start with and it won't connect. Too low under load and it disconnects.

I saw this in our present campground (KOA North Austin TX) last summer when we were here and everyone had their AC on high. We were fine in the morning but as the day got hot and more AC units were running and heating everything up, one side of the 50A service would start to sag until it hit 109 volts and then the Progressive said TOO LOW and shut us down. The voltage then went back to 119 VAC on that leg.

The other leg was 120 VAC with no load but only dropped to 116 VAC under the same 22 Amp load. They moved us to another site but we had the same problem, just took a bit longer to get to the 109 VAC cutoff point.

For me, I just let the Progressive do its thing and don't worry about it. After I plug in, I just wait for the big CLICK when the contactors pull in and then look at the display to see what the actual voltage is. As they say, your mileage may vary.

[wa8yxm]

Two answers: IN theory yes.. In practice you will find the tips on the probes are too short.. Or at least I do.. I have one modified so I can use it to check, (NOTE NOT TEST but Check) 50 amp service

With the round-ish pin either top or bottom you should see

120 volts either side to either center (Round or flat)
240 volts side to side.

No voltage or low voltage to round = open ground
No or low voltage to center flat = open neutral

Either case do not use

No voltage side to side.. Do not use

[CampDaven]

PI PT-50C. Good readings? Done!
Don't mess with good

[adamfolger]

My EMS is smarter than I am. It was engineered by people WAY SMARTER than I am. I have a hard wired and a portable. They are not likely to fail at the same time. As an assistant park manager I have observed that the biggest mistake RVers make is plugging in to the ped without flipping the breaker off. Keep welding the plug prongs and you will fry the EMS.

[Jim T.]

Originally Posted by marjoa

I do have a Progressive Ind EMS-HW50C. My procedure usually is:
1) turn off all breakers in MH
2) check post power with tester
3) If post is ok, plugin
4) check read out on Progressive Ind EMS-HW50C monitor
5) turn on breakers

Maybe over kill but rather be safe than sorry.

Answers to other question:
I did try to move my tester tips to the side of the receptacle but couldn't get contact. I looked closely and the contacts were way in there. When I finally plugged my cord in it made contact just fine. EMS-HW50C Monitor read out good electrical feed, turned on breakers.

Good idea on this suggestion:
You can also plug an adapter in the 50 amp socket and the pull out a little so the blades are slightly exposed

I also have the Progressive EMS hard wired unit, but I made up this for testing park power before I even pull into the site. If it isn't good-to-go, I go!

[CampDaven]

Originally Posted by Jim T.

I also have the Progressive EMS hard wired unit, but I made up this for testing park power before I even pull into the site. If it isn't good-to-go, I go!

Attachment 145395

My PT-50C does that.
Seems to be a dichotomy of capabilities.
I win.

[TechWriter]

Originally Posted by marjoa

So I watched a good YT video on how to test pole service before you plug in. I bought a recommended tester. Went to test at our CG and the tips are to short to reach way into the 50amp service circuits to test. Do they make extensions for these things?

Using a meter to test pedestal voltage is like using a shovel to remove snow. Sure it works, but I'll take a snowblower any day.

I mean it's dark and you're fumbling around with extra long probe leads hoping you don't "cross the streams" or praying spiders/wasps don't start dropping from the pedestal cover onto your hands.

Ditch the meter. Use a Progressive or a TRCI surge guard or a Power Pal (this is a link). BTW, the Power Pal is the fastest . . . and it talks!

[Jim T.]

Originally Posted by CampDaven

My PT-50C does that.
Seems to be a dichotomy of capabilities.
I win.

I didn't know that I had entered a contest.

Since the Progressive EMS measures continuously, it provides protection while plugged into park power. My device, which essentially measures that same functions as the Progressive EMS, is only used to verify that park power is safe to use at that precise moment in time before committing my coach to a particular site's power connection. If it indicates a problem, I either move to another site and/or contact the campground representative to alert them about their problem.

Anal retentive? Maybe. But I'm comfortable in my skin.

By the way, the definition of dichotomy is: A division into two parts or classifications, especially when they are sharply distinguished or opposed: the dichotomy between eastern and western cultures.

My Progressive EMS and my homemade tester are complementary to each other, not in opposition.

[PanJH]

Originally Posted by Jim T.

I also have the Progressive EMS hard wired unit, but I made up this for testing park power before I even pull into the site. If it isn't good-to-go, I go!

Attachment 145395

I made one similar to that-- I also use it as a preliminary check before plugging in.

[Jim T.]

Panjh,

Good to know that I'm not the only obsessive/compulsive RVer! On my last RV trip, I ran into a missing or loose neutral on a park pedestal that indicated excessive voltage on my tester. I know that my Progressive EMS would have not let power through to my coach, but with my handy tester, I didn't even have to deal with the hassle. I just moved on.

[CapnJustice]

Originally Posted by Rambeau

yes, you can get extensions. You can also plug an adapter in the 50 amp socket and the pull out a little so the blades are slightly exposed...better yet get a Progressive Ind EMS-HW50C and be protected. A voltage reading with a meter is nothing more that false security

+1
Just installed that myself. Comes OUT of the transfer switch so protects against both shore and generator power. Any nobody can steal it.

[bamaspiveys]

Originally Posted by marjoa

Ok I get that but here's why I choose to did the meter thing. When we had our TT, we found a really nice spot. At that time I had a portable EMS unit. So the first thing I did was to walk over to the post and plugged it in to see if the green lights came on and verified that the post had good power BEFORE I backed in and started "doing other stuff". So in this example the lights did come on, verified power was good, so we backed in, leveled and started doing all the "other stuff". I went around and plugged in the 30amp power cord to our portable EMS and it started to give me bad readings. After trouble shooting I realized that this post was not delivering good power after all. SO.......we had to UNDO the "other stuff" we did and move. Big hassle.

So when we bought this MH, one of the first things I did was install a hard wired EMS-HW50C for all the many reasons mentioned on this site. But as an added precaution, because of what happened in the above example, I wanted to again, verify that the power was good before we go into any kind of setup up mode or "doing other stuff". So I watched this video on YT to show me how to do this. (see below) It just seemed to me that even though I'm now covered with the EMS-HW50C, instead of driving through or backing up into position where I can pull out the cord, plug it in see what the readings are from the EMS-HW50C, why not check the electrical post 1st by walking up to it and testing it. Seemed to me that would save me a lot of hassle only to find out that, that post had insufficient power and then have to put the cord back into the bay, pull the rig out and find another site. All that positioning to do that exercise was for nothing.

A few weeks ago I posted here how to check a CG electrical post BEFORE I plugged in and one of the suggestions was to buy what SpaceNorman did and buy a portable unit also. (Even though he uses that as his permanent source) Well that's a couple of hundred bucks or more and I wasn't going to do that. So that's why I decided to do what the YT video suggested.

I hope I'm making sense here. If there's a better, inexpensive, safer and reliable way, to check the post for power before I go through all the hassle of getting into position to test it with the MH's poser cord I'm open. Do you all see where I'm coming from?

Your thoughts...?

Video that I watched is here:

So I am unclear the EMS indicated clean power until you connected the RV, then it started reporting issues. I assume it protected the RV from these issues? What was the actual issue that changed between connecting the EMS and the RV?

[marjoa]

Originally Posted by bamaspiveys

So I am unclear the EMS indicated clean power until you connected the RV, then it started reporting issues. I assume it protected the RV from these issues? What was the actual issue that changed between connecting the EMS and the RV?

A lot of you missed the total point of my post. Jim T got it perfect. My hard wired unit worked perfectly. I never questioned it's ability. What I was saying was.......

Instead of going through all the hassle of pulling into a spot, yanking out the power cord, plugging it in and seeing if you're good to go....WHY NOT just walk up to the post 1st, test it. If alls good, THEN go through what's necessary to position your coach to setup camp and plug in permanently etc. Saves a lot of hassle that way and that's what Jim T said he does and that's what I want to do just was looking for a reliable, inexpensive way to do that.