E8 Error Code - Low/High Frequency on EMS

nander

Texas North Chapter Leaders-retired
Dave created an extension cord from our old 50 amp power cord. He put a new female end on it and was able to connect the rv power cord to it and then connect to an outlet. This is not a 50amp outlet, but smaller as it is as our house.

When plugged in, the EMS lets the power come on, but shows an error code of E8. If we take the 'extension cord' off, no error. The error code is low/high frequency. What does this mean and why do I care about the frequency of the line?

Thanks for your help and insight!
 

For20hunter

Pacific Region Directors-Retired
In looking up the error codes, an E-8 Code is: Line Frequency Low (line frequency below 51 cycles per second. If AC power frequency deviates plus or minus 9 hertz from 60 cycles per second, the EMS will shut down AC power to protect the coach. An E7 indicates the frequency is too high and E8 indicates its too low. My guess is that there is either a problem with your cord that was rewired.

Did you ever use that same receptacle for the trailer before the 50 amp cord was rewired?


Rod
 

danemayer

Well-known member
Nancy,

I'm a little hazy on this, but I think the frequency represents how fast the alternating current alternates. Motors and compressors (fan and air conditioners) might run at the wrong speed. And if I'm not mistaken, that may not be healthy for the motors.

Not sure what effect it might have on electronics.

I guess the mystery is why the extension cord is causing this. Of that I have no idea.
 

AAdams

Well-known member
The frequency of AC is used for counters in electronics. So if you only have 50 cycles per second then your clock will only run 50 seconds in a minute. The refresh rate on your TV will not be as fast etc. What the actual harm to the equipment is I do not know.
 

Bohemian

Well-known member
I would suspect too much resistance or a bad connection so that it is getting an incorrect frequency reading.

Also, how is it wired. 50A is a 2 phase connection. 30, 25, 20A are all single phase. You could be getting power by induction.
 

MCTalley

Well-known member
It's been a while since I finally dropped out of electrical engineering and went back to computer science, but I think the two hot legs on a 50 amp connection are on different phases. If you tied both hots together to use as a single hot, the incoming power will be a mixture of the two phases and will probably look like some oddball frequency to the EMS. The voltages would probably still average out around 110-120.

Looking at the original post again, this might not be applicable to the OP.
 

TedS

Well-known member
When Dave made the extension cord, did he bind L1 and L2 line inputs together at the house end of the cord? Did he connect neutral to house neutral and ground to house ground? This assumes you are adapting to a 15 or 20 amp household outlet and not connecting to a 50 amp rv outlet.

In either case, check extension cord continuity end to end to be sure it is correct.
 

nander

Texas North Chapter Leaders-retired
Thank you for your replies. The extension cord was a new power cord. He cut the trailer end off and installed a female plug. It is wired like they said in the instructions. It was then plugged into a 30amp house plug. We spoke to an electrician at Lowes and he said the extension cord + trailer cord was too long for the 30amp plug.

He is installing a 50amp rv plug, so we will test it again once that is finished.

Thanks again for your replies!!
 

danemayer

Well-known member
Re: Ehttps://heartlandowners.org/forum.php8 Error Code - Low/High Frequency on EMS

Nancy,

You might point Dave to this folder. The 30 amp pages may help. There are lots of ways to make mistakes with residential 30 amp receptacles supplying power to RVs.
 

SNOKING

Well-known member
So both of the hots should go to the single 30A hot lead. The ground and neutral get carried thru.

14-50r.png


30-ampRV-front8.jpg


So the black wire on the 30Amp cable needs to connected to both 50amp hot leads. The green 30amp cable needs to connect to the 50Amp ground(round) lead. The Neutral while 30amp cable needs to be connect to the 50Amp neutral across for the round ground terminal.

Chris
 

TedS

Well-known member
So both of the hots should go to the single 30A hot lead. The ground and neutral get carried thru.

14-50r.png


30-ampRV-front8.jpg


So the black wire on the 30Amp cable needs to connected to both 50amp hot leads. The green 30amp cable needs to connect to the 50Amp ground(round) lead. The Neutral while 30amp cable needs to be connect to the 50Amp neutral across for the round ground terminal.

Chris

This is what a 30 to 50 amp dogbone will do so you can adapt a 50 amp cord to a 30 amp outlet.

- - - Updated - - -

Thank you for your replies. The extension cord was a new power cord. He cut the trailer end off and installed a female plug. It is wired like they said in the instructions. It was then plugged into a 30amp house plug. We spoke to an electrician at Lowes and he said the extension cord + trailer cord was too long for the 30amp plug.

He is installing a 50amp rv plug, so we will test it again once that is finished.

Thanks again for your replies!!

Your 50 amp cord + extension will not cause excess voltage drop when plugged in to a 30 amp outlet. The wire size is large enough to carry 30 amps.
 

nander

Texas North Chapter Leaders-retired
Re: Ehttps://heartlandowners.org/forum.php8 Error Code - Low/High Frequency on EMS

Nancy,

You might point Dave to this folder. The 30 amp pages may help. There are lots of ways to make mistakes with residential 30 amp receptacles supplying power to RVs.

Thanks, Dan! I had already printed the info on the 50amp receptacle. The info is what he is using to install the 50amp plug on the outside of his shop.

I should clarify, there isn't a problem with the 30 amp plug, just the extension cord. We don't get the error code with just the trailer plugged in.

Thanks for all the help! Love this forum!!!
 
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