Electrical Issues on Shore Power But Not on Generator

[Magic-carpet]

From the OP's screen shots its showing "inverter" in the top right corner of the screen. It doesn't know its hooked up to shore power. I'm sticking with a communication problem. Wherever he's at its hot..! All three A/c's are showing over 100 degrees..!

To answer one of the questions I'd refer to this diagram. The VT understands how the pedestal is wired.

"The second image has a shore power selection option in the upper left corner. As you can see, it was on 30 amps when I took the photo. The problem is, the panel doesn’t allow me to select anything higher than 30 amps, even though the coach is connected to 50 amp shore power. I can select lower amp numbers but can’t get it to go any higher than 30. I seem to recall the system automatically recognizing when the coach is connected to 50 amp power, but I have no idea how it distinguishes between 30 amp power and 50 amp power. If anyone knows, I’d be interested in the explanation."

[LWBAZ]

Thanks to all of you for your thoughts and suggestions.

Based on what I found this morning, the problem is exactly what “ditto” and “Magic-carpet” suspected. Below are several photos:

Photo #1 shows the com cable they referred to. It’s about 14 inches total length. As you can see, one end of the cable is plugged into the bottom of the transfer switch, while the other end connects to a similar orange cable.

Photo #2 shows my cable removed from the coach. As you can see, the blue wire on the left side of the photo has broken loose from the pin inside the Molex connector. I was working in that area trying to diagnose my power problem, but I presume the wire was already broken by that time. In any case, it’s a small-gauge delicate wire with relatively few strands inside, so it wouldn’t take much to cause a failure. And as you can see in the first photo, the cable is pretty much hanging there in space, subject to moving back & forth as the coach rolls down the road. Sort of like taking a piece of bailing wire and bending it back & forth multiple times. Sooner or later, it will break.

To be clear, I’m not saying that’s what happened and I’m not blaming anyone (other than myself as an always distinct possibility…). Regardless of the cause, the wire is broken and I’m 99% sure that break is what’s causing of my power problem.

Photo #3 provides a closer view of the broken wire.

Photo #4 shows a close-up of the printed label from the cable. It reads, “MINI PLUG TO MINI MOLEX CONNECTOR 70013 2 PIN.”

I could repair my existing cable, but would need to order a pin extraction tool, a new pin, and possibly a specialized crimping tool from Molex or one of their retailers. I’m thinking it will be quicker and less expensive to simply order a new cable.

I don’t know if the cable was fabricated by Entegra, supplied by the manufacturer of the transfer switch (Southwire Surge Guard), or came from somewhere else. I’ve sent an e-mail to Entegra customer support and Firefly customer support to see if/where I can obtain a new cable.

In the meantime I’m going to see if I can jury-rig a temporary fix to the existing cable, just so I can reinstall it and confirm the broken wire was the cause of my power issue. I’ll post an update here once I do that.

Regarding the multiple suggestions to check for 240 volts on the two hot legs, yes, I checked that, on both the input side and the output side of the transfer switch.

[brobox]

Larry, thank you for your post, the timing was impeccable. I had the reverse today when I started the generator to run the roof airs when the Temps hit 98*. Comm. error from the Generator to the Vega Touch. Remembered your post and went right to it, took 1/2 an hour, but thanks to your post, it worked.

[LWBAZ]

As noted in my post above, I decided to pursue a temporary fix of my broken transfer-switch-to-Vegatouch cable. I had several thoughts regarding how I might do it, but nothing that seemed like it was going to work all that well.

To get a better look at what I was dealing with, I shot a photo of the Molex connector with the broken wire. Loaded that photo to my computer, then zoomed way in on it. The first photo below shows what I saw. A couple of things were evident:

1) The pin for the white wire (the wire that ISN’T broken off) wasn’t fully crimped. The way Molex pins work, you first crimp a portion of the pin to bare wire, then you crimp the “arms” at the end of the pin around the insulation of the wire. Look closely and you’ll see that the last step wasn’t done on the white wire.

2) The pin for the blue wire (the wire that IS broken off) did appear to have been properly crimped, or at least close. You can see the “arms” at the end of the pin were at least somewhat crimped around insulation of the wire. But not all that well, because when the blue wire broke, the insulation came right out of the arms.

Bottom line, no gold stars for whoever did the crimping.

After considering several approaches to a temporary fix, it hit me that maybe I could use the metal barrel from a butt connector, and if I could find one just the right size it might fit tightly enough over the Molex pin to work. I figured anything bigger than a red butt connector (made for 18 to 22 gauge wire) was going to be too big. So I got a red butt connector and used a small hacksaw to cut the red plastic insulation off of the metal barrel inside.

At first the metal barrel appeared to be too small to go over the Molex pin, but with some rotating and light pressure, it went on and actually seemed reasonably tight. Wahoo! From there, I stripped a little insulation off the blue wire, put the bare wire into the barrel, and crudely crimped it down with diagonal pliers. You can see the finished work of art (NOT!) in the second photo below, along with an intact red butt connector for reference.

From there I wrapped the temporary fix with black electrical tape to hopefully keep everything in place until I can get a replacement cable. Next it was out to the motorhome for installation and test, which is covered in the next post.

[LWBAZ]

With my crudely repaired cable in hand, I went out to the RV garage and connected it up. Turned on the 50 amp shore power and stepped inside the coach, hoping for the best. Fortunately the news was good!

The first photo below shows the home screen on the Vegatouch. Note that the image in the upper right corner indicates 60 Hertz Shore Power, 121 volts on one leg, 119 volts on the other. Just below that you can see that both chargers are in Absorb mode, with Charger 1 hitting the battery bank with 100 amps of DC and Charger 2 hitting the bank with 95 amps of DC.

The second photo shows the shore power selection screen, and the good news is it’s now showing 50 amp shore power.

The third photo shows the inverter settings screen, and everything looks good there too. Up to and including this photo, I hadn’t turned on any of the three rooftop AC units.

The fourth/last photo was taken after I turned on the three AC units and let all of them come up to speed. At that point you can see the AC Power display is showing 19 amps on one leg and 42 amps on the other. As you might expect, the leg with the higher amp number has two of the three AC units on it.

Bottom line, everything is good (other than the current weather here in the Phoenix area). Pretty amazing what havoc one little broken wire can wreak.

Thanks VERY much to all of you for your advice & assistance. I MIGHT have eventually figured this out on my own, but I don’t even want to think about how long it could and likely would have taken.

[777 Driver]

Originally Posted by LWBAZ

After considering several approaches to a temporary fix, it hit me that maybe I could use the metal barrel from a butt connector, and if I could find one just the right size it might fit tightly enough over the Molex pin to work. I figured anything bigger than a red butt connector (made for 18 to 22 gauge wire) was going to be too big. So I got a red butt connector and used a small hacksaw to cut the red plastic insulation off of the metal barrel inside.

Larry,

Adapt and overcome!

I've successfully used a hot glue gun to fuse loose wires into position to preclude them from shifting. Might be easier than trying to wrap small gauge wires with electrical tape.

Congratulations on your methodical troubleshooting and innovative repair!

Take care,
Stu

[Butte64]

Thanks for all the great details on the cause and solution.

[Rollin101]

Originally Posted by 777 Driver

Larry,

Adapt and overcome!

I've successfully used a hot glue gun to fuse loose wires into position to preclude them from shifting. Might be easier than trying to wrap small gauge wires with electrical tape.

Congratulations on your methodical troubleshooting and innovative repair!

Take care,
Stu

Stu, do you have an A&P license to accomplish that fix or was it an inflight emergency?

[777 Driver]

Originally Posted by Rollin101

Stu, do you have an A&P license to accomplish that fix or was it an inflight emergency?

Neither...certainly wouldn't pass a QA check, but, it works. Temporarily.

Take care,
Stu

P.S. Per 14 CFR § 91.3, in an in-flight emergency requiring immediate action, the pilot in command may deviate from any rule of this part to the extent required to meet that emergency.

[LWBAZ]

Originally Posted by 777 Driver

Larry,

Adapt and overcome!

I've successfully used a hot glue gun to fuse loose wires into position to preclude them from shifting. Might be easier than trying to wrap small gauge wires with electrical tape.

Congratulations on your methodical troubleshooting and innovative repair!

Take care,
Stu

Good tip Stu - thanks!

My intent is to obtain a replacement cable and keep the current one as a spare (which hopefully won't be needed).

[Magic-carpet]

Glad you got it up and running..! Let us know if you are able to get a new cable from Firefly or EC.

[HarleySG]

Nice post...thanks Larry!!

[LWBAZ]

Originally Posted by Magic-carpet

Glad you got it up and running..! Let us know if you are able to get a new cable from Firefly or EC.

I learned from the fine folks in the Entegra customer support group that the cable is made by Firefly. I'm working with Firefly to obtain a new one.

In the meantime, my significantly-less-than-elegant temporary fix is still working as of this morning.

[757driver]

Larry,

First let me say nice problem solving and fix.

Not to put a damper on your situation but somewhere you still have a problem. Perhaps only an indication problem but something is not right.

In picture 1 the two chargers show a decent AH going to the batteries but the indicated voltage of the house batteries shows 13.0v and in Absorb. This should not be possible because your setting for Absorb is 14.3v. This may be an indication problem and a fault with where Vegatouch takes its voltage reading from.

In picture 3 (one minute later) the chargers show a decent AH going to the batteries but the Absorb voltage shows 13.8v which is still low but better than the 13.0v on the other screen. Again it may be an indication problem only but it would be interesting to see what the actual voltage at the house batteries was during this charge phase.

In picture 4 (4 minutes later) the chargers still show in Absorb charge but the house battery voltage has dropped to 12.7v. Once in Absorb the chargers (and voltage) should stay at 14.3v for at least 2.5 hours (as determined by your Amp Hour setting).

Some strange indications indeed. Perhaps a Vegatouch reset will cure this but I would want to look into it further to ensure the house batteries were being charged properly.