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phil-garver avatar image
phil-garver asked

VM-3P75CT Split Phase - Any issue?

Hello,

As I am building out my new RV system one component at a time, the main issue I have is being able to monitor the shore power current to avoid overloads. I would like to use the 3P75CT to do this at the inbound lines to the panel. Are there any issues with using this in a split phase manner be able to monitor and alert via VRM?

split phaseinput current
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7 Answers
Mr.Orange avatar image
Mr.Orange answered ·

I have the Victron VM-3P75CT installed in a split phase system. It is working great. It has a little fast update interval compared to the EM530 or EM540 meters. Here is a screen shot of what I see. I love being able to see the reading through Victron Connect. In the settings I have it configured as Phase number to be 3-Phase. ESS has alot fast response time since the energy meter is updating faster compared to the EM24.

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** I did have to put a neutral wire in L3 voltage channel to keep the voltage of L3 at zero. The voltage on L3 would drift up to 60-80 volts.



1709511325361.png (75.2 KiB)
1709511381776.png (24.0 KiB)
1 comment
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jdfearl avatar image jdfearl commented ·
So you had 2 neutrals on it? 1 in the neutral and a neutral in L3?
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ldoes (Victron Energy) avatar image
ldoes (Victron Energy) answered ·

Hi all, split-phase support is in active development. The method given by Mr.Orange can also be used until we release this feature.

6 comments
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jrpark22000 avatar image jrpark22000 commented ·
Great, looking forward to the future update!
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jwy224 avatar image jwy224 commented ·

would this be an update to existing hardware such as the Victron VM-3P75CT where we can just purchase the larger CTs needed for North America power inlet cables or will it be a whole new device?

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kevinc-63559 avatar image kevinc-63559 jwy224 commented ·

I presume we could just clamp onto the inverter AC-IN wires, which are generally smaller than the panel wires?

Any timeline on formal split phase support? Will it just be a software update or is new hardware more likely?

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jrpark22000 avatar image
jrpark22000 answered ·

I too am a US split phase user and want to use this to monitor both legs of 120vac.

Given they are 180 phase and using the VM-3P, I'd assume the monitor would see them as separate phase?

What does the touchscreen show for l1/l2/l3 as well as vrm? Does l3 just show blank, or will it alarm or error as l3 is not used?

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jrpark22000 avatar image
jrpark22000 answered ·

I've also asked Victron this question in their recent FB post on Feb 19th. https://www.facebook.com/VictronEnergy.BV?locale=en_GB

No reply yet. I'm fearing the lack of replies to this topic (which I've seen in several places) is not good news. Split phase users in the US market aren't covered with this product.

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jrpark22000 avatar image
jrpark22000 answered ·

Thank you both! I've added a VM-3P75CT to my setup and it works just as I'd hoped. I now have visibility to my entire AC load!

3 comments
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jwy224 avatar image jwy224 commented ·

What CTs did you use? Im also in the US and would love to hook this up to my mains.

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ldoes (Victron Energy) avatar image ldoes (Victron Energy) ♦♦ jwy224 commented ·
Hi @jwy224, the VM-3P75CT is shipped including three of these 80A CTs. It's not possible to use any other CT.
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jwy224 avatar image jwy224 ldoes (Victron Energy) ♦♦ commented ·

well that sucks. Thanks for the reply.

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phil-garver avatar image
phil-garver answered ·

Thank you all for verifying this! One thought / proposed question.... With the way many RV's are being setup in the US right now, the panel comes in with 50amp split phase, they then run a portion of the panel out on a separate 30amp line to the inverter/charger, and then back again to the panel to the segmented circuts. I realize this gives them the ability to do an all-in-one panel, but messes with solutions when we just want to use an Multiplus :).

Proposal / Question... With the 3-phase, could I use 2 of them to measure the inbound 50 amp loads to see overall load, and the 3rd one to monitor just the dedicated circuit to the inverter? I am thinking then I could use it for total load visibility.(until I move the rest of the coach to Victron)

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kevinc-63559 avatar image
kevinc-63559 answered ·

Make sure your VM-3P75CT is at current firmware levels (via VRM). Mine was shipped at 1.01 and my Cerbo had a heck of a time with it. Once I upgraded to 1.06 everything stabilized.

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