mbrooke
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I think you are looking at the contactor coil, but I'm guessing. Can you mark it up? Which is A phase?
Are you calling the crankcase heater a motor overload? If not, I see no motor overloads.
See terminal C on the motors, below it.
Are they possibly single phase motors with a run winding and a starting winding? So the start winding doesn't need OL since it opens as soon as the motor starts spinning?
Edit: After I look at it again, I think the OL is common to both the run and start windings, so it does protect both windings. And it looks like the OL drops out the contactor - that keeps the run and start windings from being energized in series across L2 and L3.
The TF5 suffix on the compressor numbers designates they are 3-phase. The suffix would be PF instead for single phase units. See the links below.
The schematic symbols for the compressors are for single-phase, but that's very likely to be incorrect based on the compressor model numbers and the rest of your schematic.
Compressor schematics on pg. 68 of pdf (pg. 65 of original document) at: www.hvacrinfo.com/Compressors/Scroll.pdf
https://climate.emerson.com/documents/new-copeland-scroll-zs-ka-compressors-en-2884468.pdf
https://opi.emersonclimate.com/CPID/GRAPHICS/Types/AEB/ae1387.pdf
The drawing stinks. The C, S, and R terminals indicate a single phase compressor but those aren't single phase. The compressors have internal protection. The windings are in a wye configuration and the thermal overload breaks the common connection point on all 3 phases.
My take is that the drawing is correct, and they use the third phase on the start winding instead of a start capacitor, and the motor runs as single-phase.
A 3ph-start/1ph-run motor, if you will. And there is no OL,
:roll::happyno:
Upon closer examination, I see the OL in the motor, on the C terminal.
What's incorrect about my statement on the starting on the third phase?
If you trip one phase, then both the start and run wingdings will be in series still passing current.
So, what is correct?
3 phase supply, but the motors are incorrect pictured as single phase.
I gotcha. An inexperienced designer just grabbed the first 3-terminal motor image he/she found.
The schematic symbols for the compressors are for single-phase, but that's very likely to be incorrect based on the compressor model numbers and the rest of your schematic.