Progressive EMS

We used to use a portable Surge Guard to protect our coach from campground electrical issues, it served us very well. On one trip it suffered some plug damage to the female 50amp connector. Unfortunately that connector was part of a fully molded cable that terminated inside the “permanently” sealed case.

To fix it required complete disassemble of the unit to replace the damaged connector. Although I was successful in opening the “permanently” sealed case and replacing the damaged end, and fully re-weather proofing the unit, we knew it would have to be replaced, but we did get another year out of it!

Now we have a hardwired Progressive EMS-HW50C with two remote displays. One display (and the switch box to select between the two displays) is in our utility bay, so we can check both legs when we first hook up. The second is mounted up by our Powerline Monitor and Xantrex display in the kitchen. That’s the one that we normally have active when camped. Once we confirm the shore connection is good, we switch the output to the interior display.


We installed the new unit in our forward bay right after our main transfer switch. The transfer switch is used to pass either the genset or shoreline power to the coach. To install the EMS you:

  • Remove output from transfer switch;
  • Run new cable from transfer switch output to EMS input;
  • Hook the original transfer switch output into the EMS output.
**NOTE** Keep all strands of the #6 wire from touching the center plastic divider of the relay inside the Progressive Industries plastic box. Inattention to this point has caused the neutral output side of the relay to be compromised by a small broken piece of plastic, causing 240 volts to be applied where 120 volts is expected due to a lost neutral.

This install is not a difficult / complicated thing to do but its made very cumbersome by

  • Very tight working area in the front compartment
  • You will not believe how tough it is to get that seven strand 6 gauge wire bent around and through those inductive rings inside the Progressive Industries box.
  • There is very little room in the EMS box, the delicate electronics are close at hand, you have to get the hots through inductive rings before screwing them down to their terminals. That wire just does not like to bend.
  • Routing the display wire (standard 4 wire telephone wire) up inside the coach (for the second display) can be a chore

Overall it took about 5+ hours installing the hardwired EMS and its two displays. Sadly our first experience was only to have the unit show an early life failure, after running for 15 or so minutes the display flashed crazy 8’s and would go out. Progressive Industries was great to work with (returned my call on a Saturday), and sent out a replacement circuit board right away.

The board to replace was one of the ones inside the EMS enclosure, which meant I had to remove the 6/3 wire from the inductive rings to get the board out. Putting them back in place was no easier the second time