Hi,
Would like to know 2 stage compressor coil which mark 1,2,3 and 7,8,9, is there any difference if i connect it 789 as first step in and 123 as second step in.

Last week one of my customer 30hp 2 stage compressor burn down, i removed the coil which mark 123 as R,Y,B line (first step contactor) and 7,8,9 as RYB line (second step). Then, they passed me a secondhand 30hp coil without numbers but with 3 phase colour for both step.

I checked both coil with same ohm, check contactor contact point and changed all the necessary things like oil, filter and etc.then fixed it back. When start both part running at 16-18amp, when it getting colder dropped to 14amp, next day i changed another filter everything running smoothly, but till evening the coil burn down again (first step coil).

So would like to know 2 stage compressor coil which mark 1,2,3 and 7,8,9, is there any difference if i connect it 789 as first step in and 123 as second step in . ? I installed this system coming 4 years and this is the first time it burn down.