A Thank You to the members about low voltage

[CavemanCharlie]

This weekend I went to a campground that I have never been to before. After plugging in my 30 amp plug into the outlet and turning on the Air Conditioner I took a glance at my cheap voltage gauge that I keep in a outlet near my bed. It read very low. I also notice that the AC was making a different sound then usual. I checked to make sure that everything was plugged in good and tight. Then I felt the breaker for the 30 amp plug and it felt a little warm. So I shut everything down and dug out my 50 to 30 amp dog bone adapter. Once I plugged in with that I had great voltage and the AC sounded much, much, better.

I learned these tips by reading on this message board and I wanted to thank the members here for teaching me these types of things.

Thank You

[time2roll]

For a 30 amp RV the polarity check works fine on 50 amp with adapter. Although extremely rare to find 50 amp service with bad polarity.

No need to check both sides as the adapter and 30 amp RV only connects to one side.

If you have a 50 amp RV you need a custom adapter that checks both.

EMS protection is always best.

[SoundGuy]

Lenny K wrote:
Does this setup work for 50 amp if you use a 50 amp adapter?

SoundGuy wrote:
50 amp RV service is actually 100 amp service consisting of 50 amps across each of 2 legs so obviously if you wanted to check both legs you'd have to use 2 monitors. The simpler and better solution for those who have a rig wired with 50 amp main service is to invest in a 50 amp EMS which is designed to check & continuously monitor both legs of that 50 amp service.

DrewE wrote:
Basically correct, but it's inaccurate to call it a 100A service. It is a 50A 120V/240V split phase service. None of the wires or connections ever have 100A flowing, and you don't need wire sized to carry 100A, and you cannot power a single 100A 120V device should you happen to have such a beast. You can use up to 50A at 240V, or have two legs of 50A at 120V, but not a single leg at 100A.

No need to blow this out of proportion, I never said anything about 100 amp flowing through any single connection nor powering a single 100A 120v device. :S I merely responded to the question as to whether polarity checkers or type of dongle I built for myself for use with 30 amp campsite service is suitable for also checking 50 amp campsite service, the answer being no because 50 amp RV service is across 2 legs whereas 30 amp service is across a single leg ... but of course you already know that. :R

[DrewE]

SoundGuy wrote:

Lenny K wrote:
Does this setup work for 50 amp if you use a 50 amp adapter?

50 amp RV service is actually 100 amp service consisting of 50 amps across each of 2 legs so obviously if you wanted to check both legs you'd have to use 2 monitors. The simpler and better solution for those who have a rig wired with 50 amp main service is to invest in a 50 amp EMS which is designed to check & continuously monitor both legs of that 50 amp service.

Basically correct, but it's inaccurate to call it a 100A service. It is a 50A 120V/240V split phase service. None of the wires or connections ever have 100A flowing, and you don't need wire sized to carry 100A, and you cannot power a single 100A 120V device should you happen to have such a beast. You can use up to 50A at 240V, or have two legs of 50A at 120V, but not a single leg at 100A.

Similarly, a semi tractor pulling dual 28' trailers is not a truck with a 56' trailer. The two are far from equivalent if you have some 35' long pipes to haul.

[SoundGuy]

Lenny K wrote:
Does this setup work for 50 amp if you use a 50 amp adapter?

50 amp RV service is actually 100 amp service consisting of 50 amps across each of 2 legs so obviously if you wanted to check both legs you'd have to use 2 monitors. The simpler and better solution for those who have a rig wired with 50 amp main service is to invest in a 50 amp EMS which is designed to check & continuously monitor both legs of that 50 amp service.

[Lenny_K]

SoundGuy wrote:

pasusan wrote:
This is what I use along with this.



and



You can use it at the pedestal with the adapter and use it inside without.

Sure you can BUT the downside is when plugged into a 30 amp campsite power post the meter will be upside down :M , ergo the reason I built my own dongle that allows that same Prime Products meter to sit correctly when plugged into the campsite power post. :B

Does this setup work for 50 amp if you use a 50 amp adapter?

[SoundGuy]

pasusan wrote:
This is what I use along with this.



and



You can use it at the pedestal with the adapter and use it inside without.

Sure you can BUT the downside is when plugged into a 30 amp campsite power post the meter will be upside down :M , ergo the reason I built my own dongle that allows that same Prime Products meter to sit correctly when plugged into the campsite power post. :B

[pasusan]

CavemanCharlie wrote:
Checking the voltage at the pedestal before plugging in is a good idea but, not fool proof. The voltage will sometimes read fine until you put a large load ; like an air conditioner; on it.

Checking for polarity would be a good idea. I should get myself one of those little light tester things. What are the called if I look for them on Amazon ?

This is what I use along with this.



and



You can use it at the pedestal with the adapter and use it inside without.

[SoundGuy]

CavemanCharlie wrote:
Checking for polarity would be a good idea. I should get myself one of those little light tester things. What are the called if I look for them on Amazon ?

Ummmm - polarity tester / checker. 😉

[CavemanCharlie]

Checking the voltage at the pedestal before plugging in is a good idea but, not fool proof. The voltage will sometimes read fine until you put a large load ; like an air conditioner; on it.

Checking for polarity would be a good idea. I should get myself one of those little light tester things. What are the called if I look for them on Amazon ?

[Bobbo]

SoundGuy wrote:

rockhillmanor wrote:
I have had the shore station input change after plugged in and I saw it on yellow tester that tells you exactly what the problem is. :C

Which is pointless if it can't do anything about the "problem" whereas an EMS will by automatically disconnecting the rig from the problematic source. The same argument applies to simple surge protectors that can detect an issue such as a missing ground but don't do anything about it. Solution - use a full feature EMS instead and it will address the issue instantly a "problem" is detected.

It is also pointless unless you happen to be actually watching the meters when the problem arises. I have better things to do than sit in my camper staring at those meters. I will never have an RV without an EMS of some type.

[edatlanta]

While checking a pedestal prior to hooking up isn't a bad idea it is only a snapshot at that exact time what is going on. Conditions can and do change continuously especially in a campground with older electrical systems. I have seen neutral and ground issues crop up suddenly in numerous campgrounds as well as high and low voltage over my 8+ years of full time use. I even had an over voltage situation (over 132v) at my home base site a few years back and that was in a residential area. Each and every time my PI EMS-PT50 shut me down with no damage. I did have one PT50 sacrifice itself a couple of years ago also with no damage to my rig. At that point I just removed the dead PT50 (one leg died) and installed my spare PT50. Yep, I have two of them because I absolutely will not plug in anywhere anytime without one.

[SoundGuy]

rockhillmanor wrote:
I have had the shore station input change after plugged in and I saw it on yellow tester that tells you exactly what the problem is. :C

Which is pointless if it can't do anything about the "problem" whereas an EMS will by automatically disconnecting the rig from the problematic source. The same argument applies to simple surge protectors that can detect an issue such as a missing ground but don't do anything about it. Solution - use a full feature EMS instead and it will address the issue instantly a "problem" is detected.

[rockhillmanor]

Bobbo wrote:
I have a Progressive Industries EMS-HW30C (this is its second RV as I pulled it out of my Class C before trading for my TT) but I STILL use this before plugging in every time.

X2
I use these also.
Short sweet and to the point to see if shore station is wired properly and voltage. I check it "before" I even drag out any of my RV power cords/surge protectors.

AND after I am all all tested and plugged in the shore station, the testers then get plugged into an outlet above the kitchen sink inside the RV. So I can see what's going on during my entire stay.

I have had the shore station input change after plugged in and I saw it on yellow tester that tells you exactly what the problem is. :C


And the volt meter showed me why the cord and plug on an oil heater was melting. In the area of Florida I was staying at would "brown out" the electric when it got cold at night. :R

[pianotuna]

Hi,

I check voltage under load before I plug in. If it is low, then I use an autoformer to correct the voltage.

I'm not comfortable with voltage below 107, so the PI and SG are not too useful for me.

[IAMICHABOD]

Like Bobbo I always check with my home made pedestal checker I made several years ago,cheap but it works.

Saves me the hassle of dragging everything out.Then I hookup using my Progressive Industries EMS HW-30C.


parts list
15 amp to 30 amp Adapter
triplex outlet
Outlet tester
Volt Meter
I had all these around the house,why not use them...
I also use my 50amp to 30amp adapter to check the 50amp side. Sometimes I like them better as the are in better shape.