Honeywell Prestige SD YTHX9321R1000 Wireless Tstat
It's late and I have to get this system going tomorrow, see if you agree.
Looking at the specs for the Tstat, it reads the Y1 & Y2 terminals are rated for .6A each. The system has four circuits with two stages with LSV's.
The LSV's are the MKC Sporlan coils rated at 15 w each, that already takes the Y1, Y2 amps up above what the terminals are rated, now add the contactor coils in the condensers and it is almost 4 times rated amps.
I am, thinking and it is VERY late, I will have to figure out some kind of isolation relays for the Y1 & Y2 outputs.