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Charlie and Martha · 03-19-2018, 01:02 PM

EMS WIRING TO TRANSFER SWITCH WIRING HELP NEEDED.

First a disclosure. I am color blind but I will have my wife to identify wire colors.

We wintered in South Texas this year. We are now making our way to the West Coast via as much BLM and National Parks that we can find along the way.

The problem:

1. I had an RVIA Certified Tech wire in my new Progressive 50 Amp EMS.

2. We tried to use generator power today and although the Generator runs properly transfer of power does not occur.

3. Thinking the main breaker in the load center tripped I checked it and found it to be ok but reset it to no avail.

4. I then checked the 30 Amp breaker at the Onan gen set and it was not tripped but I reset it to no avail.

5. After scratching my head for a while I pulled out the control panel and coolant hose panel to check the fuses that were on the underside of the main breaker switch. Both were good as tested with an ohm meeter.

So, that brings me to improper wiring (maybe). Does anyone have a proper wiring schematic that would aid me in wiring my Hardwired EMS-LCHW50 RV Surge & Electrical Protector to a Parallax ATS 503? Any help including hand drawn schematics or perhaps a photo of such an installation would help.

twinboat · 03-19-2018, 01:17 PM

All I can add is that most EMS devices are installed before the transfer switch, in line with the shore cord.. They are there to protect from bad shore power.

If yours is wired that way, it will not effect the generator input to the transfer switch.

TJ · 03-19-2018, 01:20 PM

I was thinking the same thing. I'm wondering whether you have another breaker on the generator that is tripped and preventing power transfer.

TJ

TJ · 03-19-2018, 01:27 PM

I was thinking the same thing. I'm wondering whether you have another breaker on the generator that is tripped and preventing power transfer.

TJ

ewlee · 03-19-2018, 01:46 PM

Your tech may have tripped the breaker on the side of your charger/inverter, that would prevent power from passing through.

nothermark · 03-19-2018, 01:50 PM

It looks like we have quite a crowd with the same thoughts. Check the installation and see if he wired the EMS to the shore cord side of the transfer switch or the output of the transfer switch. A visual wire check may be all one needs to figure that out.

If you do not have one it's time to pick up a voltmeter and watch a video about how to use it. $20 or less should do the job.

twinboat · 03-19-2018, 02:09 PM

The wiring is pretty simple.

The EMS will be marked L1, L2, N and ground, both going in and coming out. So will the transfer switch terminals.

L1 and L2 should be black and red, which one it goes to doesn't matter.

N will be white and ground will be green or a bare wire.

Scottybdivin · 03-19-2018, 02:20 PM

Charlie, I wired a HW50C into my 1st rig. The hardest part of the whole job is getting into tight spaces. Everything else is POC, as long as you can identify Red, Black, White, and Green wires. Progressive has good installation instructions on their site.

For voltage testing, start at the source and work your way down line. If the HW50C is wired before the ATS, there should be a direct path from the generator to the ATS. Check both legs on both sides of the ATS. If you don't have power to the ATS, something is tripped on the generator. If you have power IN, but not OUT, the ATS is bad. If you have power IN/OUT, something downline is tripped. Keep following the path.

Charlie and Martha · 03-19-2018, 02:52 PM

I tend to agree with the problem analysis but want to double check myself. The following is how the tech wired the EMS into the transfer switch (I've marked each wire and what circuit they belong to.

This is the circuit on the ATS

One last thing. I noticed that the 35 amp breaker on the Onan has very little tension when you toggle it. Is this normal? The genset and transfer process were working perfectly prior to EMS installation.

Thanks in advance

twinboat · 03-19-2018, 03:03 PM

The switch looks wired correctly and the EMS is wired before the transfer switch.

Line is the incoming power from shore cord, passing thru EMS to the transfer switch.

You can start the generator and watch the transfer switch to see if it switchs over after the 30 second delay.

Does the generator breaker look like a double wide breaker or could there be a second breaker somewhere.

"007" · 03-19-2018, 04:00 PM

DID the tech check out everything for you when he was done?
Most Gen's have been 50 amp with two circuit beakers on GEN and the GEN will transfer the TS supplying your 110 in your coach.
Your wiring looks OK in pictures if its your wiring.
Gen may have a cable lead from terminal box feeding its power and the load center may feed from transfer switch with 20 amp Romax cables.
You will find older TS's wiring diagrams in this link.

cruzbill · 03-19-2018, 04:04 PM

Call your tech and have him come out, last guy to touch it.........

Charlie and Martha · 03-19-2018, 04:45 PM

Quote:

Originally Posted by twinboat

The switch looks wired correctly and the EMS is wired before the transfer switch.

Line is the incoming power from shore cord, passing thru EMS to the transfer switch.

You can start the generator and watch the transfer switch to see if it switchs over after the 30 second delay.

Does the generator breaker look like a double wide breaker or could there be a second breaker somewhere.

It may be a double wide under the control panel as the four screws hold it in place are widely spaced on the top of the panel. I'll have to check it in the morning.

Charlie and Martha · 03-19-2018, 04:53 PM

Quote:

Originally Posted by 007";4093295]DID the tech check out everything for you when he was done?
Most Gen's have been 50 amp with two circuit beakers on GEN and the GEN will transfer the TS supplying your 110 in your coach.
Your wiring looks OK in pictures if its your wiring.
Gen may have a cable lead from terminal box feeding its power and the load center may feed from transfer switch with 20 amp Romax cables.
You will find older TS's wiring diagrams in [B][URL="http://www.irv2.com/forums/f54/technical-info-links-28855.html

this link.[/URL][/B]

Yes, my wiring photos of the actual equipment. Thanks for the diagrams. Is it possible that there is more than one breaker in place between the Generator and the transfer switch? I haven't found one. I have to main breakers located at the load center. One appears to be the 50 amp circuits and the other is for the 12 volt circuits. Both were un-tripped.