Originally posted by runmc
I am using 507 in my first stage and my interstage temp was only at -30F when I reach -99C.
I made the mistake of buying the wrong temp controller (on - off) for the low stage . This controller turns the low stage off when the interstage reaches -30.

Anyone have any suggestions for another controller or a work around?
Put a timer in its place or a switch and when it reaches -50 switch it on..