Questions on installing in an RV single phase breaker panel

[Mike]

I’m looking into installing a Vue into the single phase 30A breaker panel in my RV – power is very tight with only 30A total available, and I want to monitor how close I am to the max limit when using different high draw items – AC, Microwave, electric water heater, etc. – so I can manage my power usage and stop tripping breakers.

The primary issue is that the panel itself is very small, with no room inside to mount the Vue. There is space behind the panel with a 120V plugin that I could use to get power and voltage sensing for the Vue, and I think adding a simple 120V plug to the Vue’s black and white/red/blue wires would be OK from what I’ve been reading, but wanted to make sure. The space is outside of the panel, but inside of a protected space in the RV where other wires are run, the manufactured used it as sort of a semi-organized wiring chase.

The secondary issue would be space to mount the input current monitoring sensor as it is quite large. It’s only a 30A panel, and I only have 7 circuits + the main. Would it be possible to use one of the 50A current monitoring sensors on the input to the panel? It has plenty of capacity, but it looks like I’d need a 3.5mm to 2.5mm adaptor to allow it to work. Is that acceptable or a bad idea for various reasons?

[yyzguy]

while I don’t have an answer to your question, I have a couple thoughts that might help.

For the microwave you could use one of the Smart Plugs instead of installing a Vue.   Not sure if the Air conditioner or water heater use standard 120v outlets

In the panel, might the flexible sensors fit?   I had to use them at home due to having busbars and I think they might fit better in a tight location.   You might also check the low profile CTs, but I think the flexible sensors would likely work better.

• This reply was modified 2 years, 4 months ago by yyzguy. Reason: grammar

[yyzguy]

I’ll add that I have an RV and intentionally don’t attempt to run A/C and microwave at the same time.    Typically we don’t need the microwave for very long, so it’s not a big deal to turn off the A/C during those times.   My water heater is gas, so not sure how much draw those use.   I’d think once the water is up to temperature it wouldn’t need much power to maintain temperature (until you use the water…then turn off other loads).   Perhaps you have one of those fancy instant water heaters without a tank.   Do those even work on electricity?

• This reply was modified 2 years, 4 months ago by yyzguy.

[Mike]

I thought about doing a combination of smart plugs, but after thinking about it, it would be easier to just monitor the entire system at once, be able to have history, and be able to do it even when I’m not right at the coach. I can already do all that with the inverter/solar/12V battery system, which is really nice to keep an eye on it, even while the RV is stored. I have a full time internet connection so I can check on it anywhere and see if all is well. The information I get from that is great for an overall systems view, but it’s not granular enough to monitor individual 120V circuits. It would be nice if folks like Victron could integrate data from systems like the Vue, but I could find anyone who did, so having two separate monitoring systems is the best compromise I could figure out.

It’s a microwave/convection oven, and we use the convection over part a fair amount – it works much better and more consistently than the propane stove does. Some of the cooking times are 30-45 minutes, which is a long time to go without AC when it’s 90+F out, so it I knew I could turn off the TV or a few other low draw items, or even just set the AC on low for a while, that would be much better…

The water heater is gas and/or electric; you can run it on either or both, When using both, it has a passing resemblance to an undersized tankless water heater – you get way more hot water than you would from a typical 6 or 10 gallon RV hot water heater. It’s just easy to forget the electric part is on after doing dishes or a shower. At least until it trips the breaker and the AC turns off, then you definitely notice… 🙂

Thanks for the tip on the flexible sensors, they’re a lot smaller, still big, but better. I’d just need to sort out another power connection to use one of them, and it would be a power brick that will draw a wee bit more from my available 120V power. The power connection is very doable, though adding more draw is a tiny negative. That kit costs $50 more vs. the standard 8 sensor kit, which is unfortunate. On the potentially plus side, the power bricks look like output 12V DC, which is readily available in an RV, but I don’t know how tightly it would need to be regulated to work, though. I use lithium house batteries, and they range between 11V to 14V, depending on the state of charge. It depends on the circuitry inside the integrator.

I found the specs on what the current sensors output, electrically speaking, to see if the 200A and 50A sensors are comparable at https://indem.in/pages/emporia-vue-power-monitoring-systems-technical-specifications. It looks like they both output the same voltage range, and I’m inferring that internally, the Vue uses a different scale to interpret the voltage range -> amperage flow for the larger sensors. If true, that means my idea of the adaptor won’t work right (unless someone who knows the internals of the system says otherwise) as the detected amperage would be wildly wrong. Oh well.

[yyzguy]

The smart plugs do store and keep historical data, just like the Vue.   I’ve used them.

The flexible sensors are just that…flexible.   Mine are installed and a bit squished, but they work fine.   Indeed they require 12Vdc to operate the integrator circuitry.    You should be able to power them from your house battery rather than the AC to DC converter   https://en.wikipedia.org/wiki/Rogowski_coil

You could try ordering what you think you need and if it doesn’t work out, you can return them.    I did that with the low profile sensors when the flexible sensors were out of stock.   I wasn’t sure if they’d fit…they didn’t.  They gave me a full refund.    Once the flexible sensors were back in stock, I got those.

• This reply was modified 2 years, 4 months ago by yyzguy.

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