Saturday, December 2, 2023

No Shore Power!


Saturday - Another RV repair. Yesterday afternoon while I was getting dinner going, I noticed that we were running off of battery power. The Progressive Dynamics EMS system was disconnecting power due to low input voltage. When the voltage was measured at the pedestal, it was 123VAC. A bit high but definitely not low. If I bypassed the EMS and measured the voltage on an outlet not controlled by the Intellitec Smart Energy Management System, which had disconnected all the other outlets and appliances, it was only 75VAC. I disconnected from shore power and started the generator. Everything worked so the Smart EMS system worked as it’s supposed to. 

We ran off battery power last night using the propane furnace for heat. The batteries were down to 40% by the morning. 

When I measured the voltage on the automatic transfer switch with a very small load, the input voltage was fine but the output voltage was low. After picking up some fine sandpaper, I used it to clean the relay contacts in the transfer switch. I also reeled out the shore power cable. And tested again. All worked as it was supposed to. No low voltages. I will be replacing the automatic transfer switch as the contacts are still running warm. But the real culprit is the cord reel. The contacts inside the reel are probably burned and depending on the position of the reel, it works or not. The contacts are needed to transfer power from the rotating reel and the stationary hub which feeds to the EMS. The contacts are non-replaceable, according to the manufacturer, and a replacement reel is $1200. I will probably remove the reel and replace it with a twist-lock connector for the shore power cable. But for now, power has been restored to the RV.


  1. Problems such as these are interesting to me.

  2. Years ago, I smelled smoke and found burned wire contacts and melted insulation in the auto transfer switch. Sloppy wiring technique by installer was the culprit so did a thorough inspection. Found a few more. Hasty installers or just age means these things need periodic inspection. which reminds me...