HVAC Training: What is DDC

[@argonkellis]

I’m in my second year of bas controls and this video would have been amazing to watch right off the bat. Awesome job!

[@NEACHTWAIN]

Great video. Little tip for anyone in the field, these U-line Automated Logic cards operate in a antiquated way compared to modern stuff. The U-line cards (any controller that has a U before the numbers, IE U551, U220, U341V+, etc.) are controlled by a master controller, called a UNI16 or UNI32. All of the programs for the slave devices in the U-net are held in the UNI card. The slave devices essentially act like expanders to the UNI card. The slave devices do not communicate back to the BMS head end, only the UNI controller does. If an individual equipment is not running but the rest of the controllers on that network trunk are working, the end device has (probably) failed. If you have several VAV boxes/FCUs that are not working, and they are in the relative same location, like on the same floor or same section of the building, its most likely the UNI card that is having problems. Always check for 24V input and solid terminations on the RS485 connection (will be labeled as CMNet, ARCNet or U-net on the controller). I was a master tech for Automated logic and I have a lot of experience with these guys.

[@davidmunt3179]

Thanks. I work with ALC products, and I'll keep this in mind, if I'm doing service on these older controller versions.

[@washedupwarvet2027]

Shit do you work in the Boston area? Been having ALC issues for months and can’t get anyone here to fix it. They’ve sent out a guy a few times but he literally spends half the day on the phone with someone else. My last building was Continuum(super easy) but I actually like automated logic. I’ve learned alot and like the options it has.

[@andrewjacks8671]

Had a thought as I was listening to you. The inputs are your eyes reading/seeing system operating conditions. The outputs are the hands flipping switches and turning dials. Always thinking of new ways to explain things to the new guys, so thanks.

[@Kimbrelloo]

Sad we need a laptop to run a Heat Pump now.... Used to have all the Mechanical parts on the van for Borg Warner to MarvAir to every brand

[@LC-qi5ff]

Sounds like a dream

[@andrewjacks8671]

If you can figure out how to get a contactor control speed/frequency for a compressor you will be a rich man.

[@allen17sbmvp]

Great video, was just getting taught this week on this. Your explanation was definitely easier. Ty

[@HVACTIME]

Thank you, it's awesome to hear your getting actual training on the subject. The industry needs more.

[@paulgarcia458]

I did a bunch of hydronic VAV piping at FAU in boca, going back some years,

[@mechanicalenvironments]

This is great! Thanks you for taking the time to put this together!

[@jefftrain68]

Awesome! Thank you!

[@RobertTuck-vo8cw]

IC = Integrated Circuit.

[@williambutler374]

will you create some content that details troubleshooting a FLN that is daisy chained?

[@thomascrane8130]

How does a CDC input work when it confirms flow please

[@thesilentonevictor]

I heard you said ice machine interesting you all rounder I guess tech

[@HVACTIME]

Yeah I did my years in low temp before I got into chillers and heavy commercial.