Only getting 30A indicated on 50A connection

[CatchinBluegill]

I recently bought a 2009 Bounder 35H, it has 50A service via an Intellitec Smart EMS, model 900.

I had my electrician (licensed, bonded, experienced, has been doing work for my family for many years and has never messed anything up) add a 50A-240V circuit for shore power, and the voltages test correctly at the socket, as described in this thread.

Measured voltage is 235V across the outside pair, and 118 on each of the 120V pairs.

However, the panel only reports 30A service, among the choices of Gen Set, 50A, 30A, 20A.

I measured voltage at the RV end of the power cable, and am seeing a lot of voltage loss. Measured voltage at the RV end of the cable is 185 across the outside pair, and 88V on the 120V legs. I'm losing 60V on the 240 and (consistently), 30V on each of the 120V legs, over a 25 foot cable.

Is this just a bad power cable, or do I need to look for some other issue? When I got the RV, there was a gap of about 1/2 inch between the end of the outer cable jacket and the male plug, so I had my electrician replace that plug at the same time he installed my 50A circuit, but perhaps some evil lurks in the heart of that cable anyway?

Thanks!

[CA_Traveler]

My 04 Endeavor MH had a detachable 50A cord. The plugs were inside a storage locker used to store the cord. I don't know why Monaco choose this more expensive approach.

[Alan_Hepburn]

Our 2007 Bounder 35E has a detachable cord...

[Big_Katuna]

My uncles Damon has a Marinco style plug in shore power plug.

[Rick_Jay]

Ed,

Our 2005 GBM is 50 Amp and has a factory detachable shore power cord. Never thought of it as an issue and have seen other A's with a similar connection.

~Rick

[dougrainer]

Ed_Gee wrote:

wolfe10 wrote:

Ed_Gee wrote:

enblethen wrote:
Many rigs have detachable shore power cords.
Detachable power cord

Yes, 5th wheels do. The original poster has a Class A motor home. Those do NOT have detachable power cables.

Actually, some motorhomes DO have detachable shore power cords.

I am curious what class A motor home has a factory detachable power cord. I have never seen one - and I have seen thousands. Then again, I'm not referring to decades old motor homes, either.

Ed, What is your expertise that you can state this? Thousands????? What do you do that you can state that? On the other hand, I have 36 years as a RV Tech(primarily Motorhomes), and while it is not common, there are a lot of Motorhomes(Class A/Class C) that DO have detachable Power cords both 30 and 50 amp. Doug

[hohenwald48]

Deleted

[CA_Traveler]

enblethen wrote:
I would check your power readings either in the coach with all breakers turned off, or at the rig end of shore power cable.
Sure sounds like a neutral problem.

X2

I believe he suggested that it might be a cockpit problem. But definitely worth checking again with no load and then with a load. I'd turn all electronic related CBs off and just use resistive loads like ceramic heaters.

[enblethen]

I would check your power readings either in the coach with all breakers turned off, or at the rig end of shore power cable.
Sure sounds like a neutral problem.

[CatchinBluegill]

enblethen wrote:
J6 is the power to the shedding relays, in and out.
J3 appears to be the current sensor.
On the attached electrical drawing I do not see any connection to the circuit board(EMS)

Hey, thanks for that link! I found a hard copy of the 900 manual, but really like to have everything in soft copy. Cool! 🙂

If you're talking about the picture on P. 15, I don't see an explicit link either, but observed data and the description in the last paragraph on P. 14 both seem to suggest that there is one.

On the other hand, I just went out and tested the theory that a CB on the Line 2 side should also cause it drop back into 30A mode (as CA Traveler also suggested it should), and to my surprise, even with all Line 2 CBs off, it still showed 30A mode.

With all CBs off except the 20A for the Washer/Dryer, it continued to show 50A mode. Turning that one off causes a switch to 30A mode.

I'll also ask Fleetwood about it, FWIW.

[enblethen]

Yes, it is the branch breaker for the items that could be shedded.
Drawing shows a "jumper between the branch breaker and the relay contacts.
Since the OP has got the system working, I would only suggest that he checks the voltages as he did originally with the power cord disconnected and check the rig end to verify that the readings are goo.
I am not suggesting he go in and change anything. (as long as it continues to work)

[CA_Traveler]

enblethen wrote:
J6 is the power to the shedding relays, in and out.
J3 appears to be the current sensor.
On the attached electrical drawing I do not see any connection to the circuit board(EMS) to any breakers.
Here is manual for the 900
900 Manual

From that manual I believe you are misinterpreting the information. To me a Line 1 breaker does not mean the 50A breaker. From my experience it's a 20A breaker that feeds the relay for load shedding and for 240V detection. J1 and J3 are used for 240V detection and for 2 20A load shedding appliances.

Yes I saw the Model 700 text below which is right below the Model 900 at the top of the page - go figure. Perhaps there are other questionable portions of the manual.

To insure proper operation of the source sensing circuitry on the 50 AMP EMS Model 700, jumper wires must always be connected from a Line 1 breaker to J6 terminal 3, and from a Line 2 breaker to J6 terminal 1. These connections must be made even though Relay 1 or Relay 2 may not be used for controlled loads.

J6 terminals
1 From Circuit Breaker for Relay 2 ( )
2 Output of Relay 2
3 From Circuit Breaker for Relay 1 ( ) 1 From Circuit Breaker for Relay 2 ( )
4 Output of Relay 1

[enblethen]

J6 is the power to the shedding relays, in and out.
J3 appears to be the current sensor.
On the attached electrical drawing I do not see any connection to the circuit board(EMS) to any breakers.
Here is manual for the 900
900 Manual

I know of one Pace Arrow with a 30 amp shore power that came with detachable cord. It was mounted in the electrical/fresh water compartment.

[rgatijnet1]

CatchinBluegill wrote:


Honest question: why _wouldn't_ a coach vendor put on a detachable cable? That makes it easier to replace the cable if necessary.

It would only save the few minutes it takes to disconnect the four connectors at the coach transfer switch.
I have seen coaches where the generator had to be plugged in to supply power to the coach. Then that same cord was used to plug in to the shore power pedestal when you wanted outside power. I've never had a Class A with a separate power cord but there may be some advantages.

[CatchinBluegill]

I am curious what class A motor home has a factory detachable power cord. I have never seen one - and I have seen thousands. Then again, I'm not referring to decades old motor homes, either.

My 2009 Bounder 35H, at least. I didn't look at whether the power cord was detachable or not on other Bounders that I considered before buying this one, so I can't comment on whether or not that's ubiquitous in the Bounder line, but mine, at least, has a marine-type locking connection at the RV end.

Honest question: why _wouldn't_ a coach vendor put on a detachable cable? That makes it easier to replace the cable if necessary.