120V/240V split phase voltage reference

[endurofever]

Lols, yeah, this is an older home that has 6 dedicated circuits for the kitchen and the rest of the home shares the rest. Not balanced well circuit-wise either.

I think asking the goal prompted me to realize that I’m mostly interested in monitoring voltage on each leg (would love each circuit but I have UPSes to do that where I have tech) as we have heavy A/C load here in summer with unstable power and the voltage really fluctuates). My home lab barely breaks 5amp in reality and pushes PoE all over our property.

[overeasy]

Short answer is you should be fine with your 120V reference.

You probably read this post, but in case you missed it:

120V/240V split phase voltage reference

I’ve been monitoring my US split-phase service for two years now using a single 120V reference on one “leg” of the service. The results have been excellent, with overall and individual results within 1% of the utility meter and several revenue grade EKM meters on individual circuits. I long ago became comfortable with the notion of the single 120V reference, even though that voltage typically varies between 119V and 121V throughout the day with excursions even further off the mean from time to…

So IMO while I think that using a 240V reference calibrated down to half is technically more accurate, it’s not perfect either and in your case would be splitting hairs. You don’t really have a large imbalance.

[endurofever]

Thanks, I may leave the single 120v VT on its own didicated circuit in the lab to provide clean data and use the other phase for network. If I puruit the 240v VT, which unit would you recomend in the US and will it work in the 9v port?

Thanks

[overeasy]

I use a the Ideal 230V Euro model 77DE-06-09 with a 2 pin plug.

[endurofever]

Thanks, I’ve ordered the Ideal VT from Newark and an international to NEMA 6-15P adapter. I’ll wire in a NEMA 6-15P with a 10 amp 240v mini breaker in a small 2-space SE dedicated sub-panel for 240v without neutral and leave the other identical sub as is with a leg on each phase outputting 120v. It’s my basement lab, it was just a matter of time anyway and 240v loads are bigger issue in summer with A/C.

When you have time can you send any recommended calculations, calibration, etc. for this setup?

Thanks for all the support in the forums, I’m happy to have found your product.

[endurofever]

Thanks, all up and running with the 230/240 VT, calibrated to 50% of the built-in value (9.53 in my case), super simple:

Not worth the hassle for most, but I was still working on my lab wiring anyways.

[overeasy]

It looks like you found an adapter from the US 240V NEMA plug to the Euro 2 pin. Can you describe it and where you got it?

[endurofever]

I found the pass-through NEMA 6-15 plug on Amazon: https://www.amazon.com/dp/B09TP1XDKF?psc=1&ref=ppx_yo2ov_dt_b_product_details. It has a nice nug fit but certainly can let someone connect a NEMA 5-15 plug into a 6-15 receptacle if they didn’t know what they were working with.