hooked to 50 amp, board registers 30

Motorhome05 · 08-05-2006, 05:47 PM

We had the same problem last year. Took the rig into the factory and the tech said that he flipped a switch or something and the board began to register correctly. We know it is not the post because we check with a reader that tells us if the post is wired correctly before we plug in. Anyone have or solve this problem?

Motorhome05 · 08-05-2006, 05:47 PM

We had the same problem last year. Took the rig into the factory and the tech said that he flipped a switch or something and the board began to register correctly. We know it is not the post because we check with a reader that tells us if the post is wired correctly before we plug in. Anyone have or solve this problem?

Ed Gardiser · 08-06-2006, 03:56 AM

Motorhome05
You used a "reader" to check the power at the "post" and it told you its wired correctly,but does it tell you the voltage from "Line to Line" this should read 240 volts when there is 50 amp service.You will need a volt meter to check this at the "post".
Ed Gardiser
Escondido,Ca.
04 Vectra
87 Nissan PickUp
FMCA

mrschwarz · 08-07-2006, 01:44 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Ed Gardiser:
Motorhome05
You used a "reader" to check the power at the "post" and it told you its wired correctly,but does it tell you the voltage from "Line to Line" this should read 240 volts when there is 50 amp service.You will need a volt meter to check this at the "post". </div></BLOCKQUOTE>

Ed is right. The EMS infers the current by measuring the voltage accross 2 AC terminals and one DC terminal.

If the voltage across the 2 AC terminals is 110v and there is no voltage at the DC terminal, the EMS assumes it is connected to a 30 amp circuit (or 20 with the button pushed). If it measures 110v across the AC terminals and 12v at the DC terminal, it assumes that the generator is running. If it measures 220v at the AC terminals, it assumes that it connected to a 50-amp circuit.

Measure accross the 2 hot legs of the plug ro make sure you have 220 volts, not 110.

Ptribbey · 08-07-2006, 05:27 AM

Was in a RV Park in Ohio a couple of summers ago that upgraded their 30 amp posts by installing 50 amp recps on their 30 amp circuits. The EMS wasn't fooled and registered a 30 amp circuit. So don't get fooled by some underhanded methods of some RV Parks.

Bob Hatch · 08-07-2006, 05:48 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Ptribbey:
Was in a RV Park in Ohio a couple of summers ago that upgraded their 30 amp posts by installing 50 amp recps on their 30 amp circuits. The EMS wasn't fooled and registered a 30 amp circuit. So don't get fooled by some underhanded methods of some RV Parks. </div></BLOCKQUOTE>

If you know the name of the park, call the local electrical inspector, and report them. That is poetentially dangerous to the user.

PHESPE · 08-08-2006, 04:33 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Motorhome05:
We had the same problem last year. Took the rig into the factory and the tech said that he flipped a switch or something and the board began to register correctly. We know it is not the post because we check with a reader that tells us if the post is wired correctly before we plug in. Anyone have or solve this problem? </div></BLOCKQUOTE>

It is likely that you have a common problem - a bad control board in the EMS systsm.

Take a look at my post EMS Problem or do a search on my ID and you will find it

PHESPE

PHESPE · 08-08-2006, 05:05 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
Ed is right. The EMS infers the current by measuring the voltage accross 2 AC terminals and one DC terminal.

If the voltage across the 2 AC terminals is 110v and there is no voltage at the DC terminal, the EMS assumes it is connected to a 30 amp circuit (or 20 with the button pushed). If it measures 110v across the AC terminals and 12v at the DC terminal, it assumes that the generator is running. If it measures 220v at the AC terminals, it assumes that it connected to a 50-amp circuit.

Measure accross the 2 hot legs of the plug ro make sure you have 220 volts, not 110. </div></BLOCKQUOTE>

Not really how the EMS works.

The EMS system looks at the 2 power input lines, L1 and L2 - pins 4 and 6 on the EMS control Board.

If the input service is either 30(20) amp or generator there will be 0 volts ACROSS L1 and L2 - no voltage difference between L1 and L2 - as they are both connected to the incoming voltage source - a single line at 110vac.There will be 110vac from L1 and L2 to neutral – pin 1 on the EMS board

If L1 and L2 are both at 110vac, i.e. 0 vac between L1 and L2, then the EMS "knows" that the input is NOT 50 amp service. It must be either 30 amp service or Generator service. If the generator is running, the EMS will switch the Monitor Panel light to Gen, if not the Monitor panel light will be set to 30amp and the current in the neutral line will be displayed and normal load shedding will take place as required.

PHESPE

mrschwarz · 08-08-2006, 05:27 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The EMS system looks at the 2 power input lines, L1 and L2 - pins 4 and 6 on the EMS control Board.

If the input service is either 30(20) amp or generator there will be 0 volts ACROSS L1 and L2 - no voltage difference between L1 and L2 - as they are both connected to the incoming voltage source - a single line at 110vac.
PHESPE </div></BLOCKQUOTE>

Is there a neutral connected to the EMS? If not, how does it know the difference between 0 and 110 volts?

Bob Hatch · 08-08-2006, 05:35 PM

Wow, Michael, I goofed when I told you I didn't make any changes to the EMS. I just looked at the pictures, and there were changes in the jumper wires.

Did you catch that when you did the mods on your rig?

PHESPE · 08-18-2006, 04:31 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by mrschwarz:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The EMS system looks at the 2 power input lines, L1 and L2 - pins 4 and 6 on the EMS control Board.

If the input service is either 30(20) amp or generator there will be 0 volts ACROSS L1 and L2 - no voltage difference between L1 and L2 - as they are both connected to the incoming voltage source - a single line at 110vac.
PHESPE </div></BLOCKQUOTE>

Is there a neutral connected to the EMS? If not, how does it know the difference between 0 and 110 volts? </div></BLOCKQUOTE>

Sure its pin 1 on the EMS connector

PHESPE

mrschwarz · 08-19-2006, 04:13 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Bob Hatch:
Wow, Michael, I goofed when I told you I didn't make any changes to the EMS. I just looked at the pictures, and there were changes in the jumper wires.

Did you catch that when you did the mods on your rig? </div></BLOCKQUOTE>

When I rewired, I removed the jumpers and connected the other 100v leg. If I hadn't done that, the EMS would never have seen the other 120v leg.

System works great. I am on my first and the park has 50-amp plugs!

DriVer · 08-20-2006, 05:55 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Motorhome05:
Took the rig into the factory and the tech said that he flipped a switch or something and the board began to register correctly. </div></BLOCKQUOTE>When I went for service recently I thought it cautionary to turn off the circuit breaker to the water heater electrode.

Well I didn't need the electric element and I sorta forgot about it.

I plugged in the 50A cord into the pedestal and when I went inside to look at my panel it was displaying a single digit in the amps display and the amp selection LED was showing 30A.

What's up with that!

Come to find out with that breaker open the EMS panel doesn't get the information it needs to display correctly. Once I closed the breaker the EMS panel operated properly.

Just in case this happens to anyone else.

JudyandJim · 08-28-2006, 11:58 AM

Just had our Sunflyer in for service with the same problem. Our microwave circuit kept tripping, so I left it off. Decided to also turn off the dishwasher breaker because we don't have a dishwasher. It seems that breaker feeds our EMS panel, and it only displayed 30 amps incoming instead of 50, and showed only 3amps load when air conditioner was on.

The microwave breaker turned out to be a melted junction box.