Question
Hi! The current power cord looks suspect and is probably original so I'd like to replace it. It's also an old 2-prong design without a ground. The new 3-wire pigtail has a ground wire. The transformer does not have a ground wire and I'm not sure how to properly ground it. Is that a legitimate concern (was not grounded up until now)? If so, how do I ground this controller?

Answer
Thanks for your question.
I wouldn't worry about the ground wire. As you pointed out, it wasn't grounded all these years. Some of the old transformers had a tab or screw which was to serve as the ground. I can't say I ever remember any of those actually being grounded either.

Matt