I can't tell you how many times this writer has visited high-end homes, fitted with all sorts of automated systems, and witnessed mechanical rooms where some electrical panels or circuits are connected to a sizable standby generator, and one panel is not. The generator comes on automatically when the power goes out, but can only power so many circuits.
As a result, homeowners have to live without electricity from some circuits deemed “non-essential.” That could mean anything from no lights in some areas to no microwaved popcorn to no home entertainment system to accompany the popcorn munching.
This could be remedied with a device like Eaton’s Green ATS (Automatic Transfer Switch) that automatically shuts off big loads like the air conditioning in order to power other circuits—while providing whole-house surge protection, which should be considered essential when a large motor like a generator is humming.
A normal ATS that is wired into the electrical service will automatically shift the incoming power from the utility to the generator and back again when utility power resumes, but it can’t perform “active load management” to turn on and off big energy users like the AC so the generator doesn't overload and shut down.
The switch adjusts to lifestyles by turning on and off two biggest loads in the house.”
The Green ATS can shut down one or both of the two biggest loads in the house when the homeowners use other systems. Here’s a good demo of this. “The switch adjusts to lifestyles by turning on and off two biggest loads in the house,” says Adrian Sanchez V., product engineer for generators and transfer switches for Residential and Wiring Devices Division of Eaton Corp.
This isn't just a convenience feature. The Green ATS can save homeowners significant bucks by allowing a smaller generator to be used.
According to Eaton, the total cost of a 27-kilowatt generator with a 200-amp ATS is about $11,700, but a Green ATS can reduce the generator size needed to 20-kw with a 100-amp Green ATS, costing about $5,000. This also saves on greenhouse gas emissions from natural gas or liquid propane, as well as copper and steel manufacturing. In addition, a smaller generator can also be air-cooled rather than liquid-cooled (usually needed for generators over 22-kw) and requires a smaller footprint.
The Green ATS comes in a separate enclosure mounted near the electrical service and also contains Eaton’s premium whole-house surge protection rated at 108kA. It uses CT (current transformer) clamps to measure the loads, and the installer can set it up to create the controlled circuits that shut off and adjust to the generator size. It can also regularly “exercise” a generator to keep it in working order without requiring a load transfer from the utility power.
The Green ATS can work with any generator as well. It can be sold by homebuilders as a convenience, cost-saving and safety feature or upgrade.