Will an industrial label stick to a powder-coated or plastic housing?

Yes, but only with an adhesive designed for low surface energy surfaces. Standard acrylics lose much of their strength on apolar plastics: the same 3M 7818 construction peels at 5.6 N/cm from stainless steel and 2.0 N/cm from polypropylene. Ask for a modified acrylic, send a sample of the actual housing for testing, and confirm the surface is clean, dry and above the 10 °C minimum application temperature when it goes on.