Stored implies spare transformers and equipment. If by 'other equipment' you mean your microwave then nothing. An EMP is not going to get every piece of electronics everywhere so hopefully there will still be plenty of eq. to use the grid. Me? I'm building my 4kw solar power system now. I've bought an extra 4000w inverter, charger and am storing 1000w of panels just in case.
I don’t believe there is any cause for concern of a transformer not connected to a transmission/distribution line. I do not believe there is any noticeable EMP effect on a disconnected transformer.