Is there a suggested replacement for a 9999SK4 auxiliary timer which is now obsolete? It is being used on an 8536 contactor with a 120V coil.
That device was a mechanically operated pneumatic timer operated by the coil of the contactor, time delay after energization (on delay). There is no direct replacement. An alternate solution is use of a 9050JCK13V20 electronic timing relay and an 8501NR51 socket, with the timer coil wired in parallel with the starter coil as a substitute for the obsolete unit.