AC L1 vs L2 watt draw

[johnm1]

I have:

1. 50A RV with one air conditioner and we "power manage" (don't run the hairdryer when the A/C or micro are running, etc.)​
2. 50A RV outlet at the house (that we've used for several years and several campers, including this one).​
3. We use a "Conntek 14435 RV Power Cord, RV 30-Amp to 50 Amp Locking" and a "Camco Heavy-Duty Electrical Dogbone Adapter, 50 Amp Male to 30 Amp Female" to power the RV when at home.​
4. VE MultiPlus-II 12/3000/120-50 2 x 120V Inverter/Charger​
5. VE Cerbo GX Communication Centre​
6. VE GX Touch 70​
7. Progressive Industries EMS-HW50C Hardwired 50A RV Surge Protector​

Question:

1. The Cerbo GX screen shows that L1 is passing power (watts) into the Multiplus but L2 is not (see picture). Since the 50A to 30A adapter jumps the 2 hot legs together (I think), is it normal to show L2 as drawing/using no watts?
2. Shouldn't the 30A adapter be jumping L1 and L2 together and powering both legs ... and then shouldn't it be showing some sort of watt draw on the Cerbo screen?

 

[sneil]

You mention the RV is 50A and your house connection is 50A but you mention using a 50A to 30A adapter. Could you clarify if you are you connected to the 50A outlet or a 30A outlet? If connecting a 50A capable RV to 50A service, you don't need to use any adapter and I'm not sure why you would want to.

I have the same inverter & CCGX and have both a 30A and 50A connection available to plug the RV into. When I'm plugged into 50A service I'll see similar power draw as you show in the screenshot if no loads are being powered on L2. If you're not powering anything on L2 you won't see anything.

 

[johnm1]

Yes, 50A house outlet, 50A RV and I'm using the 30A adapter and 30A cord because the 50A cord isn't long enough. Right now only charging the batteries and running the electric only rv fridge.

 

[BentleyJ]

Question:

1. The Cerbo GX screen shows that L1 is passing power (watts) into the Multiplus but L2 is not (see picture). Since the 50A to 30A adapter jumps the 2 hot legs together (I think), is it normal to show L2 as drawing/using no watts?

Connecting L1 & L2 together is otherwise known as a 240V DEAD SHORT. Just a guess but I don't think you really want that.

1. Shouldn't the 30A adapter be jumping L1 and L2 together and powering both legs ... and then shouldn't it be showing some sort of watt draw on the Cerbo screen?

The adapter is a 4 pole to 3 pole device that picks up 1 Hot, Neutral & ground leaving the other Hot unconnected.

 

[rhino]

Along with what was said above you may be misunderstanding how L1/L2 work. Unless you actually have a 240V device L1 and L2 are independent of each other and power 120V devices completely separate from each other. So if you have an AC electrical outlet that is connected to L1 and another outlet is connected to L2 but only have something turned on that is connected to the L1 outlet then you won't see any power usage from L2.

 

[Supervstech]

Ok...
A 30A adapter only uses one L from the outlet...

Get rid of the adapters, and get a longer cord.

 

[johnm1]

Maybe I'm being dumb here but a 50 to 30 adapter combines L1 and L2 with a jumper (see attachment). Otherwise, how could you run everything on a camper when plugged into a generator or into a 20A or 30A power pole at some campgrounds? Now, obviously, you can't run everything at the same time but we've never had an issue with it and this is our 3rd (50A) RV that we've used the same house outlet and 30A power cords.

I don't intend on getting a longer 50A cord. They're expensive, hard to handle, I don't need it as I'll never need that much power and how could I run off of my generator when using a 50A cord without using an adapter that brings it down to a 30A or 15A plug?

If RV 50A to 30A adapters didn't work, then the well known manufacturers wouldn't make them.

 

[Supervstech]

Maybe I'm being dumb here but a 50 to 30 adapter combines L1 and L2 with a jumper (see attachment). Otherwise, how could you run everything on a camper when plugged into a generator or into a 20A or 30A power pole at some campgrounds? Now, obviously, you can't run everything at the same time but we've never had an issue with it and this is our 3rd (50A) RV that we've used the same house outlet and 30A power cords.

I don't intend on getting a longer 50A cord. They're expensive, hard to handle, I don't need it as I'll never need that much power and how could I run off of my generator when using a 50A cord without using an adapter that brings it down to a 30A or 15A plug?

If RV 50A to 30A adapters didn't work, then the well known manufacturers wouldn't make them.

No...
A 50 to 30A adapter only uses one of the 50A lines...
And a 30 to 50, just bridges the one line to both sides...

Get rid of the adapters...

 

[BentleyJ]

Please review the diagram you posted. You are not necessarily being dumb, just not actually looking at the diagram and considering that there are 2 different adapters.
You have stated that you are going FROM 50A TO 30A. That is a 4 wire to 3 wire transition therefore there is no were for one of the wires to go.

On the other hand, 30A to 50A is a 3 wire to 4 wire transition so the single hot wire gets jumpered to both hot contacts.

 

[johnm1]

Please review the diagram you posted. You are not necessarily being dumb, just not actually looking at the diagram and considering that there are 2 different adapters.
You have stated that you are going FROM 50A TO 30A. That is a 4 wire to 3 wire transition therefore there is no were for one of the wires to go.

On the other hand, 30A to 50A is a 3 wire to 4 wire transition so the single hot wire gets jumpered to both hot contacts.

Then how does a small 120VAC/2500W invertor generator (like the Honda's) work on a 50A RV?

 

[timselectric]

The 50 to 30 adapter is only providing L1, N, G to its output. The 30 to 50 adapter is bridging L1 to the L1 and L2 output.
Just guessing, because I am not familiar with Victron equipment.
If the Multiplus is looking for 240v between L1 and L2. It won't have it. And possibly won't use L2 at all.

 

[BentleyJ]

OK lets start over. WT& are you actually asking?
1) There is no power draw on L2: Answer, because the FIRST adapter 50A to 30A drops one leg. Its out of play is not connected to anything.
2) How does a small generator work: Answer, because the single hot wire in the 30A, 3 wire plug and cable gets connected to both hot prongs on the 30A to 50A adapter. So both bus bars in your 50A RV panel have power but its the SAME 120V leg. You don't get 240V.

Lastly, just because the second adapter gives you power on both legs in the RV still does not mean you will see power draw on the multiplus L2 because L2 is not connected to anything.

 

[johnm1]

OK lets start over. WT& are you actually asking?
1) There is no power draw on L2: Answer, because the FIRST adapter 50A to 30A drops one leg. Its out of play is not connected to anything.
2) How does a small generator work: Answer, because the single hot wire in the 30A, 3 wire plug and cable gets connected to both hot prongs on the 30A to 50A adapter. So both bus bars in your 50A RV panel have power but its the SAME 120V leg. You don't get 240V.

Lastly, just because the second adapter gives you power on both legs in the RV still does not mean you will see power draw on the multiplus L2 because L2 is not connected to anything.

Ahhhhh ... I think I might understand it now. I didn't think about the fact that I'm using 2 adapters! One going from 50A to 30A (at the house) and another going back up to 50A (at the RV), even though I'm not trying to force 50A out of a 30A.

I understand the 120V vs 240V at the panel and I've never had anything in a RV that used 240V so I'm good there.

The 50 to 30 adapter is only providing L1, N, G to its output. The 30 to 50 adapter is bridging L1 to the L1 and L2 output.
Just guessing, because I am not familiar with Victron equipment.
If the Multiplus is looking for 240v between L1 and L2. It won't have it. And possibly won't use L2 at all.

Could very well be the way Victron does it. I'll have to look into this further.

Also, maybe a longer 50A cord to use at home isn't a bad idea now that I have a (slightly) better understanding.

 

[Rocketman]

Just a FYI -
When using the 50a connector you have the available watts of: 50a*120v= 6,000watts per leg for a total of 12,000watts.

When you use the 30a adapter you have: 30a*120v = 3600watts total.

If you use a 15a adapter you have 15a*120v = 1800w total.

12,000w vs 3600w vs 1800w…

Such large differences…

With 2 air conditioners, microwave, plugs for kitchen, etc. you can see why the industry went to the 50a plug.