I have received my new contatctor and am ready to replace it. There are two sides I see on it. L1 and L2, and T1 and T2. Any advice from the professionals before I swap it out. I am very happy with the results on my new fan, motor, and cap. Only the contactor remains. If the old contactor doesn't have identical L1, L2 and T1, T2 markings, just go by sight, one wire at a time. That's my best guess right now. I sure don't relate to the terminal designations, although I know the motor has two lines, or L1 and L2 if you wish.
But L1 and L2 doesn't say anything to me coming from the house side, nor does T1 or T2.

Thanks.

L1 & L2 terminals are "Line" or the supply terminals. The T terminals are "Taps" that go to the fan and compressor. The contactor is simply a switch that is activated by the magnetic coil. The coil is activated by the wires from the t-stat.

My advice is to take a picture of the existing contactor with your digital camera before removing any wires. Then you can print out a copy and use it for reference when installing the wires on the new one.

If you don't have a camera, mark the wire locations on the box before removing the contactor. Install the new one and attach the wires in the same terminals. You might even draw a wiring diagram before starting.

As far as it goes, the old contactor is marked at the terminals also, but may be dusty and hard to see. The only difference in the L and T terminals may be that the number of flag connections on the T terminal may be greater than the L side. This is because you might have more wires going out than coming in.

NUMBER ONE thing to do kill the power in breaker box to condenser unit /a-c,, and to the furnace, as the furnace is what sends the low voltage power to and from the tstat,, if you was to happen to touch the stat wires together you could blow your tstat or transformer or both,, prob. Not but be safe than sorry

Thanks for the replies, I tried to rate the answers, but the system told me I had to spread the reputation around. Alrighty then, anyone have a spatula?

NUMBER ONE thing to do kill the power in breaker box to condenser unit /a-c ,,,and to the furnace,,as the furnace is what sends the low voltage power to and from the tstat,,,if you was to happen to touch the stat wires together you could blow your tstat or transformer or both,,,prob. not but be safe than sorry

Well, I am looking at the ratings on the old contactor: 240-277 vac =FLA 25, LRA 150
480 vac= FLA 25, LRA 50
600 vac =FLA 25, LRA 40
Pole Res on all three = 30 amps

The ratings on the new contactor: 277 vac = FLA 30, LRA 180
480 vac = FLA 30, LRA 150
600 vac= FLA 30, LRA 120
Pole Res on all three 40 amps

They both say 50/60 hz. 24 vac coil.

Am I good to proceed with replacement. Are the numbers OK? I am pretty sure FLA and RLA refer to amps and resistive loads I am guessing...

Go for it,, is better that the new numbers are higher than lower,,

go for it,,,,,,is better that the new numbers are higher than lower,,,,,,,


Thanks everyone...