Most published weld schedules are published in terms of AC welding. If you acquire a new control and it is an inverter/mid frequency control you probably will program in milliseconds rather than the traditional AC Cycles. The mathematical conversion is:
1 AC CYCLE = 16.7 MILLISECONDS
As in all set ups always start at a low millisecond setting on the first trial and work the time up to an acceptable weld. MFDC will heat much faster than AC since it is DC and has no zero cross overs and heats continuously. Another option is to lower the current which is very good for all the conducting components. Lowering the current and shortening the weld time are very possible on many applications.
Reference: RWMA - Resistance Welding Manual 4th edition