EMS questions?

[spock123]

I know nothing about electric and I hire someone when I need electrical work done I hire it out. My friend who has done electrical work for 40 years but never on RV’s hooked up my 50amp box to a 30amp line. I put my EMS on the box and both sides is reading 126 volts. Is that normal? I don’t want to hijack the thread but I was just wondering if someone could answer that question. Once the EMS picks up a error code how long will the error code stay after you are unplugged.

[wmtire]

This above post has been moved to it's own thread to get better answers.

[CedarCreekWoody]

What do you mean "he hooked up my box"? Did he just plug in your 50 amp RV to a 30 amp outlet using a dog bone adapter? If so then yes, both power legs would read the same voltage. Or did he wire in a 50 amp oulet in your home but hooked it to a 30 amp breaker in your circuit breaker box? If that is what he did, the it is a single 30 amp breaker, then yes both legs would read the same. But if it has a double 30 amp breaker both legs would not necessarily read the same voltage. You will also have double the power available with the double breaker. Perhaps you should ask your friend to explain what he did.

[Iwannacamp]

If you have an EMS from PI and install it as per PI instructions... to get a reading on both lines(30 am RV w/50 EMS) you install a jumper to both 110V in lines as to not have a dead line. These 2 lines will have the same reading(if my memory serves correct) as they are the same line. I did this on my old unit(30amp RV/50 amp EMS). New unit is 50 amp.

Is this what you mean?

If I read the structions correctly... the code is cleared when the powe is disconnected.

[dward51]

Originally Posted by spock123

I know nothing about electric and I hire someone when I need electrical work done I hire it out. My friend who has done electrical work for 40 years but never on RV’s hooked up my 50amp box to a 30amp line. I put my EMS on the box and both sides is reading 126 volts. Is that normal? I don’t want to hijack the thread but I was just wondering if someone could answer that question. Once the EMS picks up a error code how long will the error code stay after you are unplugged.

What exactly to do you mean when you say "hooked up my 50 amp box to a 30 amp line"?

Did he hook a 50 amp EMS box to a 30amp RV service which will be plugged into a 30 amp RV outlet?

Or, did he hook a 50 amp EMS up to a 30 amp 240v line (as in a 10/3 wire that has 2 hot 10 gauge, 30 amp L1 & L2 lines and a 3rd 10 gauge neutral and a bare copper ground), and this is plugged into a 50 amp RV outlet.

It makes a difference.

I would presume he hooked a 50amp EMS box up in a 30amp RV to be used on a 30 amp RV outlet. If that is the case, he should have only use one side of the EMS. It would show the data for one side and "0" for voltage and usage on the other side. Other than that it should work fine.

As to error codes, they should display until the power is reset (disconnected). I have not seen this, but if it displays "PE" and then a code number, that represents a "previous error code" and the condition that caused the code is now normal so the unit began to allow the power to work. An example would be you are outside or away from the trailer and the voltage drops below the acceptable value (so you would not normally be aware of this). The EMS disconnects the power to protect your components from damage. Later the power returns to normal levels and the EMS re-establishes power like normal and preserves the "PE" code for you to review later. It would still show the "PE" code when you returned hours later. The whole time during the error causing event the trailer was plugged into the RV outlet, but when there was a power the EMS prevented it from passing past the EMS. The EMS was powered the entire time, even though it disconnected the trailer side output from the EMS in the low voltage event. To clear the PE codes, you disconnect the power (unplug from the RV pedestal outlet or flip breaker on pedestal).

So the code goes away as soon as you unplug the power to the EMS either way.

[spock123]

I had a travel trailer, a Keystone Springdale 26RLL, my first camper. I wanted to have the camper hooked up to my house. I had my electrician hook the 110 volt up to a rv electric 30amp box. He made sure the wire could carry the 30amps plus the cable was installed in conduit. Then my son moved a bigger camper in that was 50amp. He did not upgrade the underground cable, he just replaced the 30amp box with a 50amp box. He ran the hot water heater on LP and he only had 1 air conditioner. I have my Cedar Creek fifth wheel there now and son camper is gone. Now my PI EMS shows 127 volts on each line. I know there is not 127 volts on each line. But again he does not deal in RV’s and my camper is to my knowledge the only camper he has ever hooked up. Guess what my PI EMS portable unit works at my house. It is showing no error code. I leave tomorrow morning for a week of camping in Pigeon Forge TN so I’ll try out the portable EMS at the same campground that the unit was showing a error code last time. I’ll post the results, the EMS has been used in eight months

[CedarCreekWoody]

It sounds as though you have 30 amp service, just rewired to allow a 50 amp to plug in. It appears he jumped the 120 volt line to both legs, which is ok. It is the same as if you used a 30 to 50 amp doggone adapter.

[dward51]

Ok, this is what I'm understanding.

1. 30amp 115v RV outlet installed at house by electrician.
2. Keystone 26RL trailer with 30amp panel and 30 amp plug.
3. Friend installed a 50amp EMS in the Keystone 26RL
4. Son changed out the 30amp RV panel at the house to a 50amp panel so he could plug in his larger trailer. But he did not change out the 30amp 115v AC feed line to 230v AC (son only has 30amps but has a 50amp plugin that splits the 30amps to both legs of his trailer panel).
5. Your Keystone 26RL is showing voltage on both sides of the 50amp EMS display (for what would normally be L1 and L2 if on a true 50amp setup).

Correct?

Assuming this is correct. I say one of two things is the cause.

1. Your friend who installed the 50amp EMS in your 30amp trailer put both inductive pickup rings over the 115v wire (both are reading the same wire). Should not be a problem at all.
2. Your son may have used a jumper to bridge L1 and L2 in his 50amp outlet so he has power to all his circuits in his larger trailer (although he still only has the total of 30amps available at any given time).

Without taking stuff apart to look, the next time you plug into a regular 30amp RV outlet, if you still see both L1 and L2 reading the same voltage and amp draw on the EMS display, then the friend used both inductive pickup donuts (no big deal).

If you only see one reading for the voltage and amp draw and the other is "0", then your son put a jumper in the 50amp box he installed on your 30amp circuit.

Thats the way I read it.

One other possibility is the friend installed one donut, but jumpered the one donut to both sides of the EMS. I don't know if a 50amp PI EMS needs to see power on both L1 and L2 to engage the relay allowing power to flow to the trailer panel. I would think not though.

Someone else with a 50amp PI EMS may have more info on this possibility, but I suspect it is either 1 or 2 above.

Oh, and it would have been easier and less expensive for your son to use a 30/50amp dogbone. Not sure why he put in the 50amp panel on 30amp service (jumpered or not).

[CedarCreekWoody]

Dward51 the inductive pickup coil is only for reading amperage, not voltage. Most likely his son installed the L1 to L2 jumper in the outlet so both lines will obviously read the voltage will read the same, but amperage readings will vary if both coils were installed.

[spock123]

I didn’t want to use a dogbone adapter. What my electrician did was tie into the line for about twenty feet to another 50amp connection that way he could plug in his 50amp travel trailer. He didn’t stay at the camper all the time and I only kept my Keystone hooked up to keep the battery charged up. Nowadays son no longer stays at my house and I have a Cedar Creek hookup to the 50amp. I am pretty sure he hooked up both side to 110 but I know I only have 30amps. I keep the Cedar Creek plugged in year round what time we are not traveling. It’s amazing that my PI EMS quit working last year and works great now. Last year it was showing I think low voltage and would shut down power to the camper. Then I would be on battery power, normally at night. I went to another campground and the PI EMS showed the same code. That time I talked to the office and they sent a electrician who changed out the connection. I plugged back in and I got the same error code. You could hear the EMS click and I would lose power. The electrician got his meter out and checked his connection and told me my EMS was bad. I took the PI EMS off and hooked my camper up and no more problems. The PI EMS did the same thing at home. Now it works. But you could hear it click and then you would lose power. I tried it at home and it was the same. I would have already sent it back if I could have found the bill of sale. I’m going to try something, the portable units are not very waterproof at all, maybe some water got in the unit. I’m going to duct tape a trash bag over it, over the top anyway

[CedarCreekWoody]

Spock, just to clarify, what exactly is your question? Both lines reading the same on a 30 amp circuit? If so, then yes that is normal.

[spock123]

Originally Posted by CedarCreekWoody

Spock, just to clarify, what exactly is your question? Both lines reading the same on a 30 amp circuit? If so, then yes that is normal.

Both sides are hooked up to one 110 line so all I have is total 110. How long does the error code stay on a PI EMS? I think my unit got wet and then dried out in 8 months in my barn. I’m going to tape a trash bag over the portable unit

[CedarCreekWoody]

The code should clear when you unplug it and plug back in.

[dward51]

You Did say it was a Progressive Industries unit, right? Those units have a lifetime warranty. So when you bought it may not matter if it's bad, they do say "a proof of purchase is required for warranty". Do you perhaps have a credit or debit card receipt for that amount at the location where you purchased it? Also some stores where you have an account can reprint a receipt for you if you know the credit card number used.

I would call Progressive about the warranty - warranty link on their website https://docs.wixstatic.com/ugd/439d5...1a4f57aa30.pdf

[dward51]

Originally Posted by CedarCreekWoody

Dward51 the inductive pickup coil is only for reading amperage, not voltage. Most likely his son installed the L1 to L2 jumper in the outlet so both lines will obviously read the voltage will read the same, but amperage readings will vary if both coils were installed.

Well Doh!!!! on my part... Should have had my coffee before posting anything about electrical stuff. Yes, Woody is right.

[spock123]

I think I have found the problem with the PI EMS. I called the company today. The problem with my unit at this campground is probably the light in the campground pedestal, the balance in the light may be the problem.

[CedarCreekWoody]

I'm glad you figured it out...

[Harvard]

This is just a fraction of what an EMS can figure out before it allows power to your RV:

The outside Hot Skin where the RV is connected to shore power BUT having an open ground allows the RV Chassis (on rubber tires) to float above Earth potential. Due to the capacitance between H and G and the capacitance between G and N the chassis will float at a VAC of about 120/2 = 60 VAC OR LESS to Earth.

The OR LESS is there because there could be capacitive coupling (or a resistive path) between the Chassis and Earth that would tend to reduce the float VAC to EARTH.

WHAT IF the Chassis to Earth VAC is greater than 120/2 = 60 VAC then there probably at least two problems:
1. The ground wire is not intact.
2. There is likely a short from a Hot Wire to Chassis: DANGEROUS as in KILLER.
3. The Earth is not a good conductor so this short circuit current will probably not trip anything except a GFCI breaker.
4. etc etc

In the process of figuring this OPEN GROUND kind of thing the EMS also knows the difference between AC Magnetic Fields and AC Electric Fields.

Here is an introduction to these AC Fields:

AC Fields are invisible forces that surround electrical equipment, power cords, and wires that carry electricity, including outdoor power lines.

•Electric Fields: These are formed whenever a wire is plugged into an outlet, even when the appliance is not turned on. The higher the voltage, the stronger the electric field.

•Magnetic Fields: These are formed when electric current is flowing within a device or wire. The greater the current, the stronger the magnetic field.

Electric Fields can occur separately or together. For example, when you plug the power cord for a lamp into a wall socket, it creates an electric field along the cord. When you turn the lamp on, the flow of current through the cord creates a magnetic field. Meanwhile, the electric field is still present.