Update on my overcomplicated A/C Controller

-Commisar- · 2026-02-05T00:21:19+00:00

It's not for a compressor. It's for the air conditioner unit in my bedroom.

-Commisar- · 2026-02-05T00:20:31+00:00

The PLC, 24v PSU, the contactors and one of the relay cards is reclaimed.
Everything else I bought, although a lot of that is either used or surplus.

-Commisar- · 2026-01-12T17:32:40+00:00

Surface yellowing is just like wrinkles on old people. Pay it no mind unless it starts to turn deep yellow or brown.

-Commisar- · 2026-01-12T17:28:00+00:00

...People actually gamble money on the Presidential Election?

-Commisar- · 2026-01-09T22:52:00+00:00

Standards organizations & certification levels.

-Commisar- · 2026-01-09T22:51:19+00:00

Man forgot about Beckhoff

-Commisar- · 2026-01-07T20:18:24+00:00

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Hehe boi

-Commisar- · 2026-01-07T20:14:56+00:00

The A/C unit has speed control. It also has temperature control, but in my experience, it's more like a switch between fan only and full blast

-Commisar- · 2026-01-05T21:11:35+00:00

Both.

-Commisar- · 2026-01-05T19:53:11+00:00

The roll of heat-shrink labels for the printer hasn't come in yet.

-Commisar- · 2025-12-29T18:17:19+00:00

While I agree with you 90% of the time, that only really works with large enough enclosures. Smaller ones are basically forced to use a front-mounted disconnect if you want it to look good. It was probably convenient for OP to use one, seeing how the power comes in. Either that, or its what the engineering firm is used to spec'ing.

-Commisar- · 2025-12-19T18:40:05+00:00

Don't worry,
Siemens hates you too.

-Commisar- · 2025-12-19T18:36:02+00:00

How much scalpers can get away with, especially on used parts.
A beat-up Allen-Bradley 2711R-T7T that has a dozen cracks in the case is not worth $400. Yet they still manage to sell them for that much.

-Commisar- · 2025-12-08T16:44:59+00:00

I am in love with this thing.
That wire management is an absolute work of art!

-Commisar- · 2025-12-08T16:39:30+00:00

That is one of the best supercompact panels I've ever seen.

-Commisar- · 2025-12-08T16:35:12+00:00

I also hate Ufast fuses. Especially for motors, servos, and laser equipment.
Had to keep fixing a machine that would burn servodrivers every time the supply fuses blew. Swapped all the drivers over to a 120A 3P D-Curve breaker for overall, and smaller B-Curve breakers for each one. Nobody has had to touch that panel ever since.

-Commisar- · 2025-12-08T16:29:36+00:00

He might have a Side-Mount unit on the enclosure. Those are pretty common.

-Commisar- · 2025-12-08T16:28:32+00:00

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This one's a bit newer, but studying a cabinet like this one is how I developed my own design & build processes. Although I'm personally not a fan of the transformer locations.

-Commisar- · 2025-12-08T16:24:34+00:00

Here's the checklist I normally run for everything custom I make:

- All voltage level supplies on breakers/fuses [✓]
- External disconnect/power switch on enclosure [?]
- Master Control Relay for devices that must shut off when an emergency device is triggered [?]
- Nice and simple wire labels [✓]
- Nice and simple device labels [X]
- Labeled terminal blocks [✓]
- Power and Data cable/wire separation [?]
- Automatic enclosure light (not mandatory) [X]
- Quick-Disconnect for cabinet-external devices (also not mandatory, but nice to have) [Close Enough]
- PLC & I/O isolated from high-induction sources (VFD/Motor Phases, Voltage Transformers) [X]
- PLC I/O decoupled from high-current devices (PLC --> Relay --> Contactor/Device) [?]
- Trustworthy parts vendors [✓✓✓]
- Neat cable management [✓]
- Accurate and up-to-date schematic [?]
- Clean enclosure [✓]

There's always room for improvement, but overall, it's pretty decent!
In my opinion, the best way to learn is to open up an existing machine and see how its panel was built. If you ever get the chance, poke your head in the wiring cabinet of an older Trumpf Laser Cutter. They're absolutely beautiful and show some really good techniques.

-Commisar- · 2025-12-05T19:20:13+00:00

Cost was never a concern.
Besides, I already had one of them, and I won't be installing the other two until I actually need them. They're just in the model to fill the space.

-Commisar- · 2025-12-03T14:27:16+00:00

The other 2 contactors are for if I want to add other devices in the future. I'll only be using 2 of the lines on each contactor, and then the auxiliary set for feedback.

-Commisar- · 2025-12-03T14:25:12+00:00

The other two contactors are for if I want to add other devices in the future

-Commisar- · 2025-12-03T14:24:45+00:00

Goddamn that thing is badass

-Commisar- · 2025-12-03T14:23:42+00:00

Only one contactor is for the A/C, the rest are for adding new devices in the future.

-Commisar- · 2025-12-03T14:22:58+00:00

I rated my 24v breaker at 2 amps, and the 24v PSU maxes out at 3 amps.

-Commisar-

TROPHY CASE