Installing MultiPlusII / How to Disconnect Factory Charger

[Ben and Kathy]

I get it now. Your gen is a single phase unit with 2 outputs that you are paralleling into the ATS. Makes sense.

Yeah, I never knew that you could run AC in parallel if it was perfectly in phase (like off the same alternator coils on a generator.) Out of phase, I think it just cancels itself out or shorts or something...

 

[Focker]

Yes very much a PITA. For my short run between the transfer switch and the Multiplus II I bought a better quality 6/4 that was flexible. Regardless, I learned this excellent stiff wire installation hack on YouTube. Posting for all: Victron Multiplus-II: Step-by-Step AC Output/Input Connection Wiring with a Spring Terminal

I watched that video and did EXACTLY that

 

[Ben and Kathy]

Ben this is awesome for me to see. I have the same insulated multi-tap connector in my hot little hands ready to install.
Regarding the fat ground wire, I originally planned on using 6/4 but I had a bunch of 6/3 laying around so I used that (a PIA to work with as you know) from the Multiplus II to the transfer switch and I guess in the case of the ground wire it worked out.
I can't wait to hear your feedback on how it works out, I am on pins and needles over here

I'll probably go out to storage this weekend and test the genny and see what happens. Need to know sooner than later. Wish me luck!

 

[Focker]

I thought I made a post on Saturday but it seems I must not have hit the Reply button so here I go again...
I opened up my transfer switch and the wires from the generator turned out to not be 6/3 wire, they are much thinner. This got me thinking that I could join the two black wires on L3 without using the multi-tap seeing that the factory installed two neutral wires in one lug. This was the first bit of fun, someone from the factory tightened those lugs like a gorilla with a breaker bar and the entire lug spun 90 degrees when I tried to loosen it. All 3 lugs for the generator were tightened in the same impossible fashion. This meant I had a broken lug and little hope of getting the others off. I used some penetrating oil spray and then an impact to get the other lugs off so I could know what I was working with. I ordered a new transfer switch that arrived quickly (ordered on Saturday and arrived today which is a Monday). I installed it tonight, joining the black wire and black with yellow strip wire on L3.
I ran the generator and the experiment did not work. I set the MP to 40A and as soon as I spun up the second AC unit the MP shut down. I backed it down to 20A and got the same result. I don't know what else to try so it looks like I may be stuck spending the dough on a Autoformer.

 

[Ben and Kathy]

I thought I made a post on Saturday but it seems I must not have hit the Reply button so here I go again...
I opened up my transfer switch and the wires from the generator turned out to not be 6/3 wire, they are much thinner. This got me thinking that I could join the two black wires on L3 without using the multi-tap seeing that the factory installed two neutral wires in one lug. This was the first bit of fun, someone from the factory tightened those lugs like a gorilla with a breaker bar and the entire lug spun 90 degrees when I tried to loosen it. All 3 lugs for the generator were tightened in the same impossible fashion. This meant I had a broken lug and little hope of getting the others off. I used some penetrating oil spray and then an impact to get the other lugs off so I could know what I was working with. I ordered a new transfer switch that arrived quickly (ordered on Saturday and arrived today which is a Monday). I installed it tonight, joining the black wire and black with yellow strip wire on L3.
I ran the generator and the experiment did not work. I set the MP to 40A and as soon as I spun up the second AC unit the MP shut down. I backed it down to 20A and got the same result. I don't know what else to try so it looks like I may be stuck spending the dough on a Autoformer.

I'm confused by your picture if that is an after change shot. It looks like you still have a hot wire going into both L1 and L2. Note that the labeling on the transfer switch terminals is confusing, you need to go by the diagram on the lid of the box. I have both legs wired into the terminal to the left of the Neutral. That may be your problem, I believe the Multiplus will ignore L2 I believe if there is not voltage on L1. Note that I have not tested mine yet, busy weekend combined with sucky weather, didn't go.

Needed something to keep the birds from nesting in my hitch so ordered a HitchVest Friday to cover the hitch; waiting for that to arrive before making the trip. Note that if you send Sales a note and reference their 10% off posting on Facebook they will send you a coupon code for an additional 10% off the sale price

 

[Focker]

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I'm confused by your picture if that is an after change shot. It looks like you still have a hot wire going into both L1 and L2. Note that the labeling on the transfer switch terminals is confusing, you need to go by the diagram on the lid of the box. I have both legs wired into the terminal to the left of the Neutral. That may be your problem, I believe the Multiplus will ignore L2 I believe if there is not voltage on L1. Note that I have not tested mine yet, busy weekend combined with sucky weather, didn't go.

This photo is what I saw when first opening up the ATS with nothing altered however when I did the mod, I followed what I thought was your photo and that of Changing Lanes where I put the black wire that is L1 into L3 so it was with the black wire with the yellow strip.
I did not touch the two wires going into L2 - Neutral. I hope this makes sense and could sure use some guidance on what I should be doing.

 

[Ben and Kathy]

`

This photo is what I saw when first opening up the ATS with nothing altered however when I did the mod, I followed what I thought was your photo and that of Changing Lanes where I put the black wire that is L1 into L3 so it was with the black wire with the yellow strip.
I did not touch the two wires going into L2 - Neutral. I hope this makes sense and could sure use some guidance on what I should be doing.

Yes, makes sense. I'll let you know how my run test goes, hopefully Thursday. I think we might have an alignment issue on terms. When I say L1 and L2 I'm referring to the two hot legs, this does not correspond directly to the labels on the transfer switch though I do believe (from memory, didn't take a picture) that the lid also has the two hot legs labeled L1 and L2 or H1 and H2. Sounds like you made the same mod I did so we'll know more once I run my test. I really hope there is not an issue on mine as I'll have to spend about 4 hours removing the wall and batteries to get to the transfer switch.

Is your genny an Onan 5500?

 

[Focker]

OK now I get what you are saying about going off the lid, I was totally going off the labels on the switch itself. 😊
I am attaching a photo for our future reference. I was running both wires to Hot 1.

Yep, I have a Onan 5500.

 

[Ben and Kathy]

@Focker Me and my Wife ran out to the RV today. Fired up the generator and had power running through the Multiplus II to the RV. I did have some kind of funky smell but that was likely exhaust from the Onan blowing back at me.

I was not able to load test this with an AC or something as it started to rain and we had to bail. This is a partial test in that I had power showing up on both legs of my surge guard. For some reason I could not get into the web console on the inverter, need to figure that out. Again, rain... Crappy weather here. It's a positive start though, confirming that the wiring is correct.

 

[Focker]

I spoke with a tech a Current Connected today and he gave me a few things to check.
His first bit of advice is leave the MP II on "Inverter On", I was testing with it set to "Charger" with the theory that it would tell me if I was getting all the amps from the generator to make everything work. He said the in-rush of power needed for the second AC is too much draw for the Multi while the generator digs in to power up everything on Charger. I am going to move the wire back to hot 1 and give it a test tonight with some hope. For me it is less about the money and more about using up more storage space installing the Autotransformer.

 

[Ben and Kathy]

I spoke with a tech a Current Connected today and he gave me a few things to check.
His first bit of advice is leave the MP II on "Inverter On", I was testing with it set to "Charger" with the theory that it would tell me if I was getting all the amps from the generator to make everything work. He said the in-rush of power needed for the second AC is too much draw for the Multi while the generator digs in to power up everything on Charger. I am going to move the wire back to hot 1 and give it a test tonight with some hope. For me it is less about the money and more about using up more storage space installing the Autotransformer.

Good to hear! Now I need to sort out why I saw or thought I saw 100 amps going across the shunt into the batteries in the phone app. I just didn't have enough time to check things and was thrown by the fact that I could not get into the local console via a browser.

The Multiplus also did not go into inverter mode when I turned on the 12v master switch. I had turned off the inverter via the web interface when we packed up to leave from the last camping trip. Also tried toggleing the phsical switch off and back to on.

I need a week of focused time with this equipment when we're not camping...

 

[Focker]

Here is my next update. I turned the MPII setting to inverter on and I set the amps on the MPII to 40. Fired up the generator, turned on the first AC and everything was smooth (this AC has a soft start). I aimed my iPhone at the MPII and took video to see what it would do when I turned on the second AC. Turned on the second AC and watched the inverter kick on and then level and go back to charging. I think the advice I was given is accurate at this point but I will do more testing to confirm.

 

[Ben and Kathy]

Here is my next update. I turned the MPII to set the inverter on and I set the amps on the MPII to 40. Fired up the generator, turned on the first AC and everything was smooth (this AC has a soft start). I aimed my iPhone at the MPII and took video to see what it would do when I turned on the second AC. Turned on the second AC and watched the inverter kick on and then level and go back to charging. I think the advice I was given is accurate at this point but I will do more testing to confirm.

That’s excellent news! I have 3 Coleman soft start kits in hand to install at the next opportunity where my Wife can join me at the RV storage. ( Safety - I won’t work on the roof without having someone there)