Powering Camper w/Victron Multiplus using a Manual Switch

[howson]

The switch above the Power Distribution Panel as shown below is what this post references.



This topic is the culmination of returning the camper to full operation after the failure of the AMSolar Smart Phase Selector (SPS) in my 2019 315RLTS. The failure is documented in the thread linked below.

• Smart Phase Selector Hum (Impending Failure?) at https://gdrvowners.com/forum/operati...ending-failure

The Smart Phase Selector's purpose was to allow all the circuits in the camper to be powered by a Victron Multiplus 12/3000 inverter/charger. This thread assumes the reader understands the Multiplus is capable of generating (sustained) 25A of 120vAC, so while all the outlets in the camper are powered not everything can be used at the same time (or is even wise to use on the inverter).

• See Victron Inverter and Battle Born Batteries in a 315RLTS at https://gdrvowners.com/forum/operati...s-in-a-315rlts

ACKNOWLEDGEMENTS
This modification was accomplished building on the work of TucsonJim and his Inverter, Transfer Switch, and Breaker Panel Modifications - Unique Solutions thread at https://gdrvowners.com/forum/operati...ique-solutions I believe Jim got this idea from @Cate&Rob as Rob used a similar type of switch on his (previous) boat.

I’d also like to thank gbkims for his counsel and also Jlawles2 for his inputs in the “hum” thread.

• @bertsch (Brian), and OffToHavasu (Curtis) are in the “penalty box” as their solution was for me to upgrade to the Multiplus II. (I’m kidding, of course.) I think ncitro (Neil) will agree an upgrade is not going to happen anytime soon! (On the replacement topic I’m serious.)

PURPOSE
This documentation spans two posts (due to picture limitations) and is verbose (for a forum thread), but necessary to accomplish the purpose which is to document:

1) Why?
2) How it Works with Schematics
3) What Was Learned During Switch Installation
4) Process and Items Used
5) What I’d Do Differently

If you quote this post, please edit to just the pertinent info you’re referencing!

Why
Due to how Grand Design wired my 2019 Reflection 315RLTS there were circuits on two different main breakers that I wanted to power off the inverter. In early 2019 the best solution to this problem appeared to be the SPS.

• A sub-panel would only power a subset of outlets so that option didn't work for me.
• There are inverters that appear to pass and/or power two 50A circuits, but none of the options in 2019 provided Power Assist (inverter aids shore power to meet demand) to both circuits simultaneously when on limited shore power or inverter only. This includes the Victron--thus the need for the SPS.
  • See https://shop.pkys.com/powerassist-demo or https://youtu.be/Odo6LNSjykQ for info on Victron’s Power Assist mode.

With the SPS’ failure in May 2021, to retain the capability of powering all the circuits there had to be a less-prone-to-failure solution. Jim’s thread led to utilizing a Blue Sea AC Rotary Switch - OFF + 2 Positions 240V AC 65A manual switch.

• Jim's trailer and the components he uses are different since his converter and inverter are two separate components. Make sure to read his document and compare to this thread to fully understand.
• Gene posted a schematic in the "hum" thread that shows yet another way to wire the switch to the Victron, so check out the other thread, too.

During the project of installing the Blue Sea switch, the circuit breakers were rearranged in the Power Distribution Panel. This ended up being quite easy to do…but still not a perfect solution as there may be occasions where I want to run the Living Room Air Conditioner’s fan off the inverter. The Blue Sea switch is still needed to meet my requirement.

• See Circuit Breaker Map (Mod from OEM) - 2019 315RLTS at https://gdrvowners.com/forum/operati...m-2019-315rlts

How It Works w/Schematics
The Blue Sea comes with a faceplate labeled Shore, Off, and Gen. These labels don’t reflect how the switch works in my setup, so the labels were changed to 50A, Off, and (not) 50A. Below is a picture of the setup in the camper as of 9 May 21.

• (not) 50A is symbolized by the line above the blue 50A label and is referenced in this thread as not 50A.
• Note that if the inverter is turned off (or in Charger only mode) no power is available in the camper on the Line 1 (Hot) circuit regardless of Blue Sea’s switch setting. The Victron Multiplus passes 50A shore power but it must be on to do so.

Below are the schematics (slightly different from those on the hum thread):





When the Blue Sea switch is set to 50A the assumption is the camper is connected to a 50A outlet so the Line 1 (Hot) and Line 2 (Hot)circuits have a separate 120v/50A leg from a grid (shore) connection.

• Line 1 (Hot) will still work with the inverter if shore power is not connected with the switch in the 50A position, but none of the circuits on Line 2 (Hot) will have power.

When the Blue Sea switch is set to OFF power stops at the switch.

When the Blue Sea switch is set to not 50A the assumption is the camper is connected to a 30A or 15A outlet; or the camper is not connected to any power source (120vAC provided exclusively by the inverter).

• If connected to 50A shore power and in the not 50A switch position, the Line 2 (Hot) circuits will not have power.

What Was Learned During Switch Installation

Using the switch for the neutrals was unnecessary. I could have used a Blue Sea 9011 switch (one less set of contacts) and then a bus bar for the neutrals.

• https://www.bluesea.com/products/901...ns_120V_AC_65A

On the Blue Sea switch, there is a metal clip that bridges contacts 2 and 4, 6 and 8, and 10 and 12. Internally pin 4 is connected to pin 3 (or 1), pin 8 to pin 5 (or 7), and pin 12 to 9 (or 11).

• Why is this important to know? If a wire is connected to the bridged side but not the contact side, the metal clip “bridge” doesn’t always make a good contact. I spent many hours troubleshooting why power wasn’t passing on Line 2 (Hot) when the lug was connected to pin 6 (and nothing was connected to pin 8).
• When I moved Line 2 (Hot)’s wire from 6 to 8 it worked perfectly.

The Multiplus, when turned off, shorts the neutral and hot lines together. (There’s no power so no harm done). Since I had power off when checking the switch for proper operation (using a multimeter) this “short” drove me nuts until I figured out what was happening.

• Keep in mind that the only way power passes through the Multiplus is with it on, there’s no issues even though the neutral and black hot are shorted when it’s off.
• Why does Victron do this?My guess is to remove any transients or capacitor-stored energy in the circuit as a safety measure.

…continued in post #2

[howson]

...continued from post #1

Process and Items Used



The Blue Sea switch: https://www.amazon.com/gp/product/B000K2MBBE

For connections I was confident would not come out of the switch I used copper cable lugs with the wires. The ring size for the switch screws is ¼”.

• https://www.amazon.com/gp/product/B073Y7H1DL

To utilize the lugs with the switch I had to remove the Blue Sea’s original screws (with integral clamp) as the clamp created a gap when used with the lug (thanks for pointing that out, Jim!). A trip to Ace Hardware for new screws and washers. (I think they were M6 x 1.00? Sorry—lost my note. The washers were M5s.)



Of course each lug was covered in heat shrink. 3/8” worked over the 6ga wire and copper lugs.

• https://www.amazon.com/gp/product/B07NVNX93K

To get all the connections needed for Line 1 (Hot) I used a 5/16” bus bar. The busbar connections need a 5/16” ring on the 6AWG copper lug.

• https://www.amazon.com/gp/product/B07C5SBZ4M
• https://www.amazon.com/gp/product/B085BNVWXR

The grounds were connected using a Square D 200 amps 120/240 volt 4 space 3 circuits Combination Mount Ground Bar Kit

• https://www.acehardware.com/departme...-centers/36347

The wire for Line 1 (Hot) out of the EMS was spliced to the Multiplus’ input using a 2 Conductor Connector and then covered with heat shrink.



A better option is an insulated version from Morris Products (thanks, Gene!).

• https://www.morrisproducts.com/pc_pr...D033ADCBEAC176

In my 315RLTS there’s enough room above the Power Distribution Panel and the hutch drawer for the switch. I ensured there’s no chance of wires rubbing against anything.



The Blue Sea switch comes with a template so drilling the holes in the side of the hutch was easy.

Getting the switch into the hutch opening and secured (with lock nuts) was a sweat-inducing wrestling match. Due to the location, connecting the wires after the switch was installed was not an option.

I wanted a cleaner look for the wires…but it wasn’t possible and not necessary given the location. The bus bar (for now) is just resting against the back of the hutch and is supported by the four connected 6AWG wires (that are stiff). The Progressive EMS is back in it’s original position (lower right of the hutch) like it was installed prior to the addition of the SPS (which is now completely removed).



Note it looks like the EMS’ output wire is against the heater line but that’s an optical illusion. Also note the corrosion on the EMS’ bottom screw. ☹

What I’d Do Differently

Use another 5/16” bus bar to connect all the neutrals instead of using the switch.

• If I had made the inverter wires long enough, the neutrals could have been combined on empty positions on the Power Distribution Panel!
• Use a Blue Sea 9011 instead of the 9019 since the neutrals won’t be attached to the switch.

As with the neutrals, if the wires going to and from the inverter were long enough, I’d attach the grounds to empty positions on the Power Distribution Panel.

Skip the connections from the bus bar to pins 11 and 9 on the switch. Go straight from the bus bar to pin 12.

• Look at the earlier schematics and hopefully you’ll understand.
• I ran out of ¼” lugs or I would made this change on my installation.

Hopefully this helps someone...took long enough to write!

Howard

[OffToHavasu]

Again in the penalty box? I deserve my own seat at this point.

@Cate&Rob that switch brings back and memories.

[TucsonJim]

Superb write up and workmanship Howard. Bravo!

Jim

[Cate&Rob]

howson

I have not yet digested all of this . . . but one comment caught my eye. Are you sure that you do not have to switch the neutrals? Neutral and ground are only supposed to be connected at the source of power. If you have them permanently bonded, when you are on shore power they are still connected at the inverter. Automatic transfer switches always "lift the neutral" when they switch to prevent this from happening. Maybe you have this covered and I haven't found it yet ?

BTW, tags to Cate&Rob are not working for some reason . . . maybe the "&" ?

Rob

[howson]

I have not yet digested all of this . . . but one comment caught my eye. Are you sure that you do not have to switch the neutrals? Neutral and ground are only supposed to be connected at the source of power. If you have them permanently bonded, when you are on shore power they are still connected at the inverter. Automatic transfer switches always "lift the neutral" when they switch to prevent this from happening. Maybe you have this covered and I haven't found it yet ?

? I didn't bond the neutrals and grounds, either temporarily or permanently. Neutrals are with neutrals and grounds with grounds.

What comment are you referencing? Obviously I didn't write something very clearly.

BTW, tags to Cate&Rob are not working for some reason . . . maybe the "&" ?

I have noticed that all the members that have a "&" in their forum name are difficult to tag. Sometimes it works, sometimes it doesn't.

[Cate&Rob]

howson

The following is my understanding (admittedly marine based) . . . OffToHavasu Curtis, am I incorrect on this ?

The inverter is a source of AC power (just like a generator) and as such the ground should join the neutral at the source. (Just like a "grounding" plug required with a floating neutral generator.) The purpose of the "safety ground" (as it used to be called) is to provide an alternate low resistance path back to the source in the event that the neutral is lost or broken. Within the trailer shore power wiring, the ground and neutral are kept separated because they come together at the campground transformer which is the "source" of shore power electricity. If the neutral and ground are connected at the inverter, when you switch to shore power you need to switch the neutrals to break the connection to ground at the inverter.

Rob

[OffToHavasu]

You are correct sir.

[TucsonJim]

howson

The following is my understanding (admittedly marine based) . . . OffToHavasu Curtis, am I incorrect on this ?

The inverter is a source of AC power (just like a generator) and as such the ground should join the neutral at the source. (Just like a "grounding" plug required with a floating neutral generator.) The purpose of the "safety ground" (as it used to be called) is to provide an alternate low resistance path back to the source in the event that the neutral is lost or broken. Within the trailer shore power wiring, the ground and neutral are kept separated because they come together at the campground transformer which is the "source" of shore power electricity. If the neutral and ground are connected at the inverter, when you switch to shore power you need to switch the neutrals to break the connection to ground at the inverter.

Rob

I believe the Victron Multi-plus switches the ground and neutral together, and breaks the connection while on shore power. But I've not done the research on this to confirm.

Edit: I found this information in one of the manuals:|

"The MultiPlus is provided with a ground relay (relay H, see appendix B) that automatically connects the Neutral output to the chassis if no external AC supply is available. If an external AC supply is provided, the ground relay H will open before the input safety relay closes. This ensures the correct operation of an earth leakage circuit breaker that is connected to the output"

"In a mobile installation (for example, with a shore current plug), interrupting the shore connection will simultaneously disconnect the grounding connection. In that case, the casing must be connected to the chassis (of the vehicle) or to the hull or grounding plate (of the boat)"

Jim

[howson]

"The MultiPlus is provided with a ground relay (relay H, see appendix B) that automatically connects the Neutral output to the chassis if no external AC supply is available. If an external AC supply is provided, the ground relay H will open before the input safety relay closes. This ensures the correct operation of an earth leakage circuit breaker that is connected to the output"

"In a mobile installation (for example, with a shore current plug), interrupting the shore connection will simultaneously disconnect the grounding connection. In that case, the casing must be connected to the chassis (of the vehicle) or to the hull or grounding plate (of the boat)"

Yes, that's correct. The Multiplus takes care of the neutral/ground bonding when it senses no shore power.

This question may take this thread OT and may be worth a thread of it's own. Consider the following scenario:

1) The trailer is connected to 50A shore power (neutral+ground bond is at the pedestal all wiring is correct)
2) 50A is being passed through both legs into the camper
3) The hot input to the inverter is broken at the inverter input. (Let's say the wire breaks, causing an open, but it doesn't short.) The Multiplus will see this as a "loss of shore power" and switch in Inverting mode.

The red hot line coming from the pedestal is bonded at the pedestal but the black line is now bonded at the inverter, too. What happens?

Jim?
Curtis OffToHavasu ?
Gene gbkims ?

[OffToHavasu]

howson what you're saying is L1 is open and L2 is closed?

[howson]

howson what you're saying is L1 is open and L2 is closed?

Yes.

With L1 open and the Multiplus on, it switches to Inverter mode and internally bonds neutral and ground.

L2 is still connected to shore power and the neutral is bonded to pedestal ground.

What happens in that (unlikely) scenario?

[OffToHavasu]

My guess is it falls to one operation, bit your have to check with the manufacturer which way it goes. If it falls to inverter then you keep both legs. If you fall to shore power you lose half your circuits.

[Cate&Rob]

Yes.

With L1 open and the Multiplus on, it switches to Inverter mode and internally bonds neutral and ground.

L2 is still connected to shore power and the neutral is bonded to pedestal ground.

What happens in that (unlikely) scenario?

L1 & L2 are both using the same neutral return. In the scenario that you describe, they are no longer exactly out of phase as they would be with L1 & L2 both from shore power. I think this overloads the neutral . . . but I am not sure what the failure mode would be.

Rob

[ncitro]

Yes, that's correct. The Multiplus takes care of the neutral/ground bonding when it senses no shore power.

This question may take this thread OT and may be worth a thread of it's own. Consider the following scenario:

1) The trailer is connected to 50A shore power (neutral+ground bond is at the pedestal all wiring is correct)
2) 50A is being passed through both legs into the camper
3) The hot input to the inverter is broken at the inverter input. (Let's say the wire breaks, causing an open, but it doesn't short.) The Multiplus will see this as a "loss of shore power" and switch in Inverting mode.

The red hot line coming from the pedestal is bonded at the pedestal but the black line is now bonded at the inverter, too. What happens?

Jim?
Curtis OffToHavasu ?
Gene gbkims ?

Yes similar to this, I’ve wondered when it’s in power assist (connected to less than 50A shore power if it’s bonding the neutral or not ( I assume not).