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New EMS shows Open Ground ?

Chakara
Explorer
Explorer
Hey guys - was hoping some of you could check my sanity.  Here at the house I have a 30A RV hookup next to the trailer.  I plug the trailer in via an 30/50 amp adapter.

I  just completed the install of the EMS-HW50C 50 amp hard wired system.  I plug in the rig and low and behold, the EMS show EC#2 - Open Ground.

Yikes!  How long have I had that problem?  

I did a bit of reading and busted out the old Fluke.  Here is what I get

Pedestal no load:

Hot to Ground:       123V
Hot to Neutral:        123V
Neutral to Ground:  0V

Input to EMS - no load:

L1 to Ground:         123V
L2 to Ground:         123V
L1 to Neutral:          123V
L2 to Neutral:          123V
Neutral to Ground:   0V

I'm not an electrician, but this all seems normal.  This is where I got a little brave (foolish?? 🙂 ) and flipped the bypass switch on the EMS.  Trailer lights up and everything works.  I put a little heater as a load and the only different measurement with a load on is:

Neutral to Ground:    1.3V

Again, I think that when you have a load you should read some voltage on that link so it still feels normal?

Before I call Progressive Ind. for an RMA - - can anyone who knows more about electricity confirm my finding?  Or am I stupid and my trailer is going to burst into flames 🙂

Thanks all!

-Kyle
???????
- 2005 Dodge 2500 5.9 6spd / Pacbrake / Airbags
- 2018 Arctic Fox 27-5L 5th Wheel
- SOLD: 2007 Keystone Raptor 299MP 33' 5th Toyhauler
- SOLD: 2010 Starcraft Autumn Ridge 246RKS 28'
- SOLD: 2004 Casita Spirit Deluxe
- SOLD: 2007 Dodge Dakota fiberglass topper
21 REPLIES 21

2naEagle
Explorer
Explorer
Also make sure the prongs on the power cord are clean and shiny.Cleaning RV Cord
2020 F350 Limited CCSB SRW
2017 North Point 315RLTS
2021 Jayco Greyhawk 29MV

Chakara
Explorer
Explorer
Ok - I thought those were normal readings - thank you for confirming that Harvard!

The EMS still shows E-2 and PE-2. E-2 implies the problem still exists.
I'll get in there and do some "wiggling" of my install to confirm everything is tight and consistent, but I'm really thinking I got a defective EMS here......

-Kyle
- 2005 Dodge 2500 5.9 6spd / Pacbrake / Airbags
- 2018 Arctic Fox 27-5L 5th Wheel
- SOLD: 2007 Keystone Raptor 299MP 33' 5th Toyhauler
- SOLD: 2010 Starcraft Autumn Ridge 246RKS 28'
- SOLD: 2004 Casita Spirit Deluxe
- SOLD: 2007 Dodge Dakota fiberglass topper

Harvard
Explorer
Explorer
All your Fluke readings are now normal, the open ground may have been an intermittent connection. If so, I would first suspect the 30/50 amp adaptor as the source of the intermittent ground.

ScottG
Nomad
Nomad
By getting 120 between hot and ground at the pedestal, you have proven the ground connection all the way back to the main panel becasue that's where ground and neutral are connected together and thus completing the circuit.

Chakara
Explorer
Explorer
Thanks Scott - I was taking those measurements from the EMS itself.

Good idea time2roll - I have one of those little yellow things around here somewhere.....

-Kyle
- 2005 Dodge 2500 5.9 6spd / Pacbrake / Airbags
- 2018 Arctic Fox 27-5L 5th Wheel
- SOLD: 2007 Keystone Raptor 299MP 33' 5th Toyhauler
- SOLD: 2010 Starcraft Autumn Ridge 246RKS 28'
- SOLD: 2004 Casita Spirit Deluxe
- SOLD: 2007 Dodge Dakota fiberglass topper

time2roll
Nomad
Nomad
I would confirm ground with a 3-light outlet tester in the RV.

ScottG
Nomad
Nomad
Since you verified the problem isn't real by getting 120V to ground, I would double check the wire connections inside the EMS.