Smart Phase Selector Hum (Impending Failure?)

[Jlawles2]

howson Howard, Home breaker panel is where most of my knowledge comes from. Lets look at a typical home panel. The panel is split left and right banks. lets focus on the left bank. The main breaker is at the top of the breaker supply bars. This breaker supplies both of the bars. One is L1 (A) and the other L2 (B). We can label the breakers starting at the top (typically) either 1-2-1-2-1-2... or A-B-A-B... The reason they alternate between 1&2 or A&B is to pull 240V from 2 120v legs.

If we look into a 3 phase breaker panel the sequence now becomes 1-2-3-1-2-3-1-2-3-1-2-3... This is because it takes 3 breakers to make 3 phase. It's always best if you start your 3 phase on 1 (rotation and L3 can be "wild").

When I see your panel, it appears it's split at the main breaker with L1 all on one side (which to me is a bit strange). Don't know if its a RV thing on the breaker panel being laid out that way.

[steve&renee]

...

Can you sketch out the manual switch you're using in a diagram? Is it like Jim's TucsonJim ? I'll have to dig up his thread later at work and see if I can figure it out.

Maybe I'm missing something, but when using a 30-50A adapter doesn't that tie the two legs together entering the camper (so both legs "see" the 30 amp connection)? I don't understand how you're isolating the 20A connection from the pedestal to the other leg. Does the pedestal 30A and 20A share the same neutral?

...

The device I'm using is made by a guy named Rowland Randall. His company is SafeRVPower. His device looks like this:

https://isteam.wsimg.com/ip/0c984316...rs=w:600,h:600

You mount the device so you can plug 20 amp shore power into it, then rewire your main distribution panel (shore power source, 2nd AC, and fireplace) so than when you throw the transfer switch, you can power the AC and fireplace either from shore power or the 20 amp aux shore power by flipping a switch.

Here's a diagram I made for Renee in case I die:




And here's a link to a video showing installation of the device:

https://youtu.be/dQbxufV2TiQ

What's cool (pun intended) is that almost all state parks have 30 amp and 20 amp service at the pole, and with this device, you can run both AC's all night without a 50 amp connection.

-Steve

[ncitro]

howson Howard, Home breaker panel is where most of my knowledge comes from. Lets look at a typical home panel. The panel is split left and right banks. lets focus on the left bank. The main breaker is at the top of the breaker supply bars. This breaker supplies both of the bars. One is L1 (A) and the other L2 (B). We can label the breakers starting at the top (typically) either 1-2-1-2-1-2... or A-B-A-B... The reason they alternate between 1&2 or A&B is to pull 240V from 2 120v legs.

If we look into a 3 phase breaker panel the sequence now becomes 1-2-3-1-2-3-1-2-3-1-2-3... This is because it takes 3 breakers to make 3 phase. It's always best if you start your 3 phase on 1 (rotation and L3 can be "wild").

When I see your panel, it appears it's split at the main breaker with L1 all on one side (which to me is a bit strange). Don't know if its a RV thing on the breaker panel being laid out that way.

Howard of correct, that is the way rv panels operate. I think the intention is to prevent you from being able to pull 240 as there as no adjacent spaces with split plates except the main spot. Every 50 amp rv panel I have seen is like this.

[ncitro]

The device I'm using is made by a guy named Rowland Randall. His company is SafeRVPower. His device looks like this:

https://isteam.wsimg.com/ip/0c984316...rs=w:600,h:600

You mount the device so you can plug 20 amp shore power into it, then rewire your main distribution panel (shore power source, 2nd AC, and fireplace) so than when you throw the transfer switch, you can power the AC and fireplace either from shore power or the 20 amp aux shore power by flipping a switch.

Here's a diagram I made for Renee in case I die:




And here's a link to a video showing installation of the device:

https://youtu.be/dQbxufV2TiQ

What's cool (pun intended) is that almost all state parks have 30 amp and 20 amp service at the pole, and with this device, you can run both AC's all night without a 50 amp connection.

-Steve

My only concern with this would be how the pedestal is wired. I’ve always assumed that they bring one feed into the pedestal and tap off of it for both the 30 and 20 amp outlet. If that’s the case it’s not designed for you to pull off of both the outlets at the same time. The more I think about it though that must not be how it’s wired or you’d pop to upstream breaker att the campground. Interesting idea.

[howson]

The device I'm using is made by a guy named Rowland Randall. His company is SafeRVPower. His device looks like this:

Very information, Steve--thank you. Your experience with the device is compelling testimony.

[steve&renee]

My only concern with this would be how the pedestal is wired. I’ve always assumed that they bring one feed into the pedestal and tap off of it for both the 30 and 20 amp outlet.

Empirically, all the times I've used the device, I'm tapping into two shore power sources. Never tripped a breaker when hooked up to 30 + 20.

-Steve

[gbkims]

Couple of issues in one post...but that's my fault. I'll address each issue in separate responses.

Before I start, let me emphasize this response is more for me as I wrestle with understanding the implications of a given configuration. It's not about what's "right" or "wrong" or which one is "better"--everyone has their own list of requirements, needs, and preferences.

gbkims , this first response is mostly to you but also to Joseph, Neil, Jim and others who may chime in...

Grounds, Neutrals, and the Drawing (referencing posts 8, 9, 10 and 11)

I understand that the grounds and neutrals are all shared in a single phase system. My question, based on the drawing provided in post 8, is if it's OK for the Victron to not have it's output neutral connected when the switch is engaged to shore power. Looking at the drawing again (fresh eyes in the morning) I'm seeing it differently--the Victron's inverter output is not connected to the loadswhen the switch is set to Shore.

I took the liberty of modifying the drawing attached to the post to show Shore engaged. Look closely at pins 9, 5, and 1 and it's obvious that the output of the Multiplus stops here when on Shore. The charger function in the Victron will work, but the inverter will not.

This won't work for me since I rely on the inverter to supply power to the bedroom air conditioner if there's a loss of shore power when we're away from the camper and the fur kids are in their kennels. It also means if shore power is lost that the residential refrigerator will lose power. If we're away for any length of time, the food will spoil.

...
When set to Inverter the two drawings respond the same with or without shore power since the Victron's pass-thru is utilized (if 15, 20 or 30A shore power is available). The Victron's Power Assist will add an additional 25A if required.

Howard,
Yes that's correct, my drawing was for either shore power with charging only, or inverter power only.

As some have said (on the victronenergy forums), connecting the shore and multiplus neutrals all together works in the RVs.

Most all the references I see are about not having the neutral connected to ground in multiple locations is the NEC.
It looks like the only time there would be two grounds on the neutral is when you're plugged into park power and there's a power outage.
The multiplus will ground the neutral when it inverters. And you'd still have the ground to neutral bond from the rv park power.

[howson]

It looks like the only time both there would be two grounds on the neutral is when you're plugged into park power and there's an outage.
The multiplus will ground the neutral when it inverters. And you'd still have the ground to neutral bond from the rv park power.

Will the Progressive EMS-HW50C prevent that possibility? I'm speculating that when shore power disconnects the EMS will disengage, effectively isolating the RV.

So...another rabbit trail that's slightly OT...but when the Victron Multiplus' Power Assist kicks in it must not bond the ground to the neutral? Scary I even thought to ask that...

I ordered a Blue Sea 9019 switch and hope to have it installed by the end of next weekend if the weather permits. Of course I'll report once complete.

[gbkims]

Will the Progressive EMS-HW50C prevent that possibility? I'm speculating that when shore power disconnects the EMS will disengage, effectively isolating the RV.

So...another rabbit trail that's slightly OT...but when the Victron Multiplus' Power Assist kicks in it must not bond the ground to the neutral? Scary I even thought to ask that...

I ordered a Blue Sea 9019 switch and hope to have it installed by the end of next weekend if the weather permits. Of course I'll report once complete.

Yeah the Power Assist had me wondering how it worked and what it does with the Ground Relay.
I was trying to understand how Power Assist does it thing.
Reading the bit in the manual makes it sound like it uses grid or generator power, syncs its inverter frequency/phase to match incoming grid/gen, then starts inverting and uses both incoming + battery to supply 120V power all by inverting.

So reading on the neutral bonded to ground at 2 places, like at home in the service panel neutral bonded to panel and in then improperly bonded also in the garage's sub panel.
Parallel current paths are created for neutral current to return from the garage sub panel to the service panel, that's what NEC 250.6 calls objectionable current.
Mike Holt - https://www.mikeholt.com/instructor2...784-sample.pdf

In the RV I think it would be a parallel path in the RV Power Cord (Neutral & Green Ground) from the Multiplus back to the rv park power pedestal.

Is this a problem? I'd probably do some measurements of Neutral & Ground current back to power source while in Power Assist if I wired it this way.

edit: The EMS disconnects both Hots & Neutral, seems it would prevent the 2 neutral bonds during a power failure.

[OffToHavasu]

I'm still a fan of installing a sub-panel to power all the inverter loads. Just seems conceptually simpler to me. I also wired in a manual transfer switch (from Safe RV Power) for the 2nd AC and fireplace. That way, if the campground has 30 amp service and 20 amp service at the pole, I can run both AC's all night long. No longer dependent on 50 amp service very often.

-Steve

An even simpler solution is getting an inverter that handles 50 amp passthrough on both phases. Then all you're doing is interrupting the incoming power, inserteting the inverter and you're done. No need for a sub panel, no need for a phase selector.

[howson]

An even simpler solution is getting an inverter that handles 50 amp passthrough on both phases. Then all you're doing is interrupting the incoming power, inserteting the inverter and you're done. No need for a sub panel, no need for a phase selector.

The "Dragon of Materialism" is tempting me big time to look at that new Victron. I...shall...resist...no matter how many times Brian, posts crowing about his setup. Keith, will be in on the act here soon, too.

[bertschb]

The "Dragon of Materialism" is tempting me big time to look at that new Victron. I...shall...resist...no matter how many times Brian, posts crowing about his setup. Keith, will be in on the act here soon, too.

Howard-
You have NO IDEA how hard it's been for me to keep silent on the obvious solution to your problem here...Glad Curtis brought it up :-)

[ncitro]

Howard-
You have NO IDEA how hard it's been for me to keep silent on the obvious solution to your problem here...Glad Curtis brought it up :-)

DONT EVEN START!! I already made the switch from the Magnum to the Victron lol

[OffToHavasu]

The "Dragon of Materialism" is tempting me big time to look at that new Victron. I...shall...resist...no matter how many times Brian, posts crowing about his setup. Keith, will be in on the act here soon, too.

Go Power has had their system to handle this out for a few years now. But since you already have all that Victron stuff, I understand why you'd stick with that. The next question, is all the stuff you have backwards compatible with the MultiPlus-II? If Yes, then there you go Nike, just do it. LOL

[howson]

So I think I've got my final configuration done and all parts are on hand. Installation will be tomorrow. If anyone has any last-minute inputs, I'd be grateful.

I'm using a 9019 (Off plus 2 position) switch with three connections instead of a 9093 which has four as Jim did in his setup because of how the Victron works (no need to isolate a Converter).

One thing that may make you scratch your head is the label choice for the knob. Shore and Gen weren't correct (the original words on the faceplate). Shore and Inverter aren't the best representation, either, as they didn't reflect what the positions actually do. 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.


The red label for the 50A reminds me the red 50A input is getting it's own independent power from the shore.

The blue label of the not 50A reminds me that Victron Inverter is in play, both inputs are tied together, and that self-management of loads in the camper is required. How much power available depends to the limited shore line I'm connected to--30A, 15A--or nothing.

When I get done I'll summarize the project and include a parts list to add to the Modification channel.

Howard