Electrical Mod -- Feedback Requested

[cookinwitdiesel]

I like the relay idea, I wonder if you can program the Victron relay outputs to do some "load shedding" on things like ACs so that when running on generator or inverter or 30 amp service, you can have the ACs turned off when the microwave is used, and then they resume when it is done. Like the "fancy" EMS system that toyhaulers have sometimes.

[howson]

I like the relay idea, I wonder if you can program the Victron relay outputs to do some "load shedding" on things like ACs so that when running on generator or inverter or 30 amp service, you can have the ACs turned off when the microwave is used, and then they resume when it is done. Like the "fancy" EMS system that toyhaulers have sometimes.

With a generator or 30A service there's no need to load-shed. I use the inverter's "Assist" feature to make up the difference when there's a demand over the available power. It's one of the incredible features of the Victron that led me to spend the extra $$$ on it and it works flawlessly in conjunction with AMSolar's SmartATS. Note this is completely different scenario from losing all external power (the purpose for the relay system I installed).

When on the inverter--that's a different story. I don't know how the inverter would know where the demand is coming from. Somehow there'd have to be a signal to the inverter that device "x" is on. That system could get complicated quick! My approach is a blunt one--lose external power=shut down (almost) everything. If I'm purposefully running the inverter it's a simple matter to manage what's on (and off). With only four batteries I'll quickly run out of juice if I don't!

[cookinwitdiesel]

I was thinking the logic would be more of:

if total power draw exceeds x then kill these circuits

Great point about the power assist, I had forgotten about that! Another useful Victron capability, doesn't the 3000va multiplus have a second set of AC outputs that are pass-through power only, not powered by the inverter. Wouldn't these achieve the same as your relay idea possibly with less complexity? There is a 32A limit on that 2nd AC output but that should be plenty.

"Two AC Outputs
The main output has no-break functionality. The MultiPlus takes over the supply to the connected loads in the event of
a grid failure or when shore-/generator power is disconnected. This happens so fast (less than 20 milliseconds) that
computers and other electronic equipment will continue to operate without disruption.
The second output is live only when AC is available on the input of the MultiPlus. Loads that should not discharge the
battery, like a water heater for example, can be connected to this output (second output available on models rated at
3kVA and more)."

[gbkims]

Howard,
Nice solution.

We used the Crydom SSRs along with Opto22 SSRs at work.
One 50A Crydom D2450 ran a small volume meter prover motor and was enclosed in a small steel electrical box out in the sun in our Texas summer heat.
Just one failure I remember of, the 1 hp 115VAC motor was humming, not rotating. Found 115V into the SSR, only 52VAC out.
The SSR wasn't mounted on a heat sink or against the enclosure's metal as couldn't drill into it b/c of the area classification, potentially flammable vapors.
It was mounted on two standoffs in the enclosure.
Motor usually pulled 10.5A, so I expect a 50A SSR was used by the mfgr of the prover for heat derating as there was no cooling and high ambient temperature in the box.
Pict of the type of box:


Took a picture of my home CB panel to see how hot my Main & A/C CBs get. Mild 90°F cloudy day today.