Smart Phase Selector Hum (Impending Failure?)

[Jlawles2]

howson Howard, Unless you are using the switch just for a bus bar, why are you breaking the neutral??? Dad always said breaking the neutral was not good, burned up contacts. Switching the neutral does not really accomplish anything in your setup.

[howson]

howson Howard, Unless you are using the switch just for a bus bar, why are you breaking the neutral??? Dad always said breaking the neutral was not good, burned up contacts. Switching the neutral does not really accomplish anything in your setup.

You're going to have to more specific by what you mean by "breaking up the neutral". Don't take the below as being argumentative, just trying to explain and understand. (Communication is hard with just text in a forum.)

The reason for the neutral wiring as you see it is to ensure there IS a neutral when connected to 50A shore and the Multiplus is inadvertently turned off. The neutral is connected across pins 2 and 3 when on 50A shore power. This is done to ensure the red hot line, which is the only side that will be fed into the camper with the Multiplus (accidentally) off, has a neutral. Remember-- when Off the Victron does not pass shore power or any connections.

Other than that one caveat the neutrals are all tied together...at least as far as I can see.

If any of that is wrong thinking, by all means forum members (including the electricians) please at least send me a PM if you don't want to post on this thread. (I'm not embarrassed if I get something wrong--happens all the time.)

[gbkims]

So I came up with 50A and not 50A. (The "not" represented by the line above it.) If on 50A shore power the switch is to the left. Anything else (inverter only, 30A shore, 15A shore, etc) the switch is to the right.

Howard,

I don't have anything to add.
I just liked the "50A", "Not 50A" as I got a memory flashback to TTL/CMOS Logic Circuits. Like a 74LS73 J-K Flip Flop with "Q", "Not Q".outputs from my old electronics days.

[Jlawles2]

howson Howard, instead of breaking the neutral why not just bus them all together to ensure you always have a neutral? Doing this gives you a spare set of contacts in the 3 pole switch should something happen.

I guess my question is more why do you think you need to disconnect the neutral from the downstream side of the inverter? is there something in the manual? If you are trying for complete isolation to prevent backfeeding the system, you also need to disconnect the grounds.

[howson]

I guess my question is more why do you think you need to disconnect the neutral from the downstream side of the inverter?

Sorry--not sure what you mean by "downstream". What I see is pin 2 and 4 (what I would call "downstream", or the Out of the inverter) always connected to the neutral. The IN is never disconnected since pin 3 always provides the neutral to (and through) the inverter.

Certainly understand that all of the neutrals could be tied together. In retrospect I could have gone with an even less expensive switch, the 9011 (with only two sets of contacts) and used a bus bar for the neutrals. Wrestling with stiff 6ga and "tying" four wires together is easier said than done.

[howson]

It's installed and works. What a wrestling match getting that switch installed with the wires attached! (Not enough room to attach the wires after installation.)

I'll post a separate thread with lessons learned, components used, how the circuit breakers were reconfigured, why the color codes, and other pertinent information. I'll post a link to that new thread in the next post (when I get it done), so please hold any questions until I get that done (tomorrow!). I'm tired.

As always, a huge thank you to my fellow moderators TucsonJim and Cate&Rob as the genesis of this project came from their original work.

[howson]

Related to this thread: Circuit Breaker Map (Mod from OEM) - 2019 315RLTS at https://gdrvowners.com/forum/operati...m-2019-315rlts

[Jlawles2]

howson Sorry Howard about the confusion. Downstream is I guess a slang term I picked up working in plants and dealing with offshore people.

I guess I use it more in reference to those items downstream.

Dropping those 4 neutrals would have def made it easier to install that switch. I don't know if you added wires or if that's what was already there, but if you can leave the wires a bit long and make a U bend or 2 it helps with relieving stress associated with trying to wrestle the switch in place.

[Jlawles2]

howson Howard, Per your request since most probably do not realize how breaker panels vary.

Howard, there was a discussion before about A-B-A-B... breaker layout. If you look at this panel https://www.granddesignrv.com/owner-...s/detail/71359 you can clearly see the breakers alternate starting with the main at the far left. In your converter the mains are in the middle with the left all on one leg, and the right on the other leg.

VS the center Main style https://www.granddesignrv.com/owner-...rts/detail/454 where the Breakers are A-A..Main-Main-B-B...

Knowing which type of breaker panel you have will help to diagnose issues. I recently had a bad connection on one of the incoming feed lines that I initially thought might be a broken or pulled wire in the slide until I pull the the Fireplace and realized everything not working was on the same leg of the power panel.

[howson]

This is an old thread, but I thought what I found today may be informative.

While harvesting parts from the Smart Phase Selector (SPS) I looked for any obvious causes of the failure. Beyond the obvious physical (mechanical) failure of the plastic parts shown in post 1, I spotted what I assume is corrosion on a relay contact. I am not 100% sure what the small relay does in the SPS, but there's definitely something going on with the relay.

In a former life (dang it was a long time ago!) I worked on office equipment. Copy machines would use a similar relay as shown in the pics below to turn on the bright light as it made it's way under the glass, scanning the image. I can distinctly remember finding a light failure due to bad mechanical relay contacts. So that's why what I saw pictured below caught my attention--I knew what to look for in the relay.

First, the small relay (you can identify where it was in the SPS by looking at post 1).



Now the corrosion (the greenish stuff) on the contacts.

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The point of showing these pictures is to show why those considering adding relays to their units may want to consider automotive-grade relays or solid-state relays, the latter being much more expensive but they draw an exceptionally small amount of power to control.

Howard