what are these components?

While you have it open, check the nuts that hold the big relay to the case. On mine, all 4 nuts worked off and rattled around till jamming the relay. Put red lock tight on each one of mine after that. If you hear any rattling go ahead and pop the case.

One thing that should be noted and not discussed is The external display also has a Bypass switch: This switch is located on the remote panel, and allows the user to bypass the computer circuit in the EMS in the event of computer failure, thus allowing source power into the RV. This does not disable the surge protection portion of the EMS.

I KNOW what they are:p Doug

CJW8 wrote:
When it absorbs too much surge and fails, PD says to return it. The circuit board with the MOV's is probably then replaced as they are sacrificial.

Yes and No. ;) The OP is talking specifically about a hard wire Progressive Industries EMS-HW50C. Yes, the MOVs used for surge protection are considered sacrificial and can eventually fail if they sustain sufficient surges but in such a case all one needs to do is call Progressive and they will mail out by USPS a new MOV circuit board. The fact the hard wire version is field serviceable is one of several reasons I chose to buy a hard wire version rather than a portable EMS-PT30C which is sealed and must be returned to Progressive for repair.

FWIW, Progressive refers to these devices as "RV Power & Surge Protection", an important distinction as these EMS units do far more than a simple surge protector.

When it absorbs too much surge and fails, PD says to return it. The circuit board with the MOV's is probably then replaced as they are sacrificial.

Sound Guy,

Thanks for the answer on the type of surge suppression the PI offers.

Here's my own Progressive EMS-HW30C ...



Circuit board at top left contains MOVs used for surge protection, circuit board to the top right controls all the other functions, including the contactor which is in the middle, with the current sensor wrapped around the output cable.

This closeup view shows the blue trim pot at the top left used for calibrating the unit and at the top right is where the time delay jumper would normally be located, with delay set to 15" with the jumper in place, 136" with the jumper removed. I've removed the jumper in mine and wired a SPST switch to the jumper receptacle contacts so I can instantly switch delay without having to open the box.



And here's the small delay jumper I removed ...

It is just as you say.

Or what part is confusing.

That's the remote display for a hardwired Progressive EMS.
I know this why? I have one...

http://www.progressiveindustries.net/#!rv-power--surge-hardwired/c1p4w

Sure - is this a trick question?

The box is obviously a hard wire EMS-HW50C, inside the plastic wrap to the right is the current sensor through which the wires run so the unit can read current draw, bottom left wrapped package is the remote monitor panel, to the right is the data cable that connects the box to the monitor panel, and at the bottom are screws to secure the box lid and wire connectors.

Anything else?