Peak load management equipment

[relztes]

I am hoping to find a way to install two pieces of testing equipment with 200 kVA and 400 kVA peak loads at site with only a 750 kVA utility transformer, 350 kVA observed peak load over the last year, and a low load factor. The existing peak load is driven by supplemental resistance heating in winter. The test equipment is all PLC-controlled, and we can program it however we want. We're fine to throttle the test equipment occasionally to stay within the available service capacity.

I am confident that it is technically possible to build a controller that measures current on each phase and provides a dynamic power limit that the test equipment follows to stay within the 750 kVA service capacity. But I have no idea how to convince an electrical engineer that some custom, unlisted piece of equipment is going to keep us from burning up the transformer.

Is there some kind of controller that can monitor power usage and shed loads to stay within a limited service capacity? Ideally, it could communicate a power limit to the equipment and give the equipment a chance to comply, but if it simply disconnected circuits according to priority when a power limit was reached, that could work, too.

Surely, we can't be the first people trying to make the most of a limited service capacity with low load factor equipment. I know EV chargers sometimes have some similar capability, and there are a few residential smart load centers available. What products exist for commercial / industrial usage?

 

[Elect117]

1) 220.87 if you have that available for the panel loading.
2) kirk key interlocking, where only one device can be on at a time.
3) You should verify if the utility requires notice when adding load of a certain amount. I know some require notice when the load is greater than 250kW.

What is your service main and switchgear rated for, and the voltage?

 

[ptonsparky]

Your logic of the program should be enough. I did it on the first PLC project I was involved with over 40 years ago. Math calc only. No analog input. Did it with analog input frequently thereafter and I am low on the scale of PLC abilities

 

[ron]

Maybe you can get the Engineer to buy into the concept showing how it is accomplished for EV chargers and the rest of the building load. Even residential.
Schneider makes a peak controller (load management module) https://download.schneider-electric...uction+sheet&p_File_Name=JYT4921902-00_EN.pdf

 

[relztes]

1) 220.87 if you have that available for the panel loading.
2) kirk key interlocking, where only one device can be on at a time.
3) You should verify if the utility requires notice when adding load of a certain amount. I know some require notice when the load is greater than 250kW.

What is your service main and switchgear rated for, and the voltage?

Thanks for the help! The kirk key interlock is a great starting point, but the ideal case is just like the EV charging example. I'll keep looking to see if there's a product like the EVlink Load Management System, but for higher power levels and generic equipment. I think our equipment vendor and we can write the PLC software easily enough, but if there's a backstop that doesn't require trusting our code, it might be better.

The main switchboard has a 2000 A bus and a 2000 AF / 1400 AT main breaker, 480 V.

Thanks for the heads up on utility notification.