Central Plant Takeover

Рет қаралды 3,448

Mr. Mechanical BAS

Күн бұрын

Пікірлер: 17

@Jeff-zk1sy 6 ай бұрын

Wow. It’s like this guy knows his stuff. What a pro

@sschueller 6 ай бұрын

Wow, documentation. I wish that was always the case...

@building-automation 6 ай бұрын

Yeah, it's pretty rough when there's no points list, and we don't have access to the existing B.A.S.

@andrewamaya8109 6 ай бұрын

What do you do when it’s not there

@building-automation 6 ай бұрын

@@andrewamaya8109 There are a few tricks you can do. Start by doing a walk through of the facility and take note of where all the devices are(pumps, chillers, boilers, ect.) Then take a good look at the controller and identify the different types of inputs and outputs. For the outputs you can use your meter to determine the different signal types being sent to get an idea of what they might control. For the inputs you might see a resistor in parallel which would indicate a 4-20mA sensor. Then trace some of the wires out of the control box and see which direction they go. If you're lucky you'll see conduits going in a direction of a group of devices like over toward all the pumps for instance. Once you have an understanding of the general layout and the signal types being sent you could begin pulling one output wire at a time from the controller and see what turns off. It would be a good idea to shutdown the chillers before you start pulling wires. If you kill a pump, or shut an isolation valve while the chiller is running you could send it into alarm or worse. Its also nice to shut everything down so its quiet and you can hear valve actuators move, or contactors pull in. If you are going to jump voltage to bring on a binary output you had better know what you are doing, it would be easy to damage components if you make a mistake.

@jasonjohnsonHVAC 6 ай бұрын

Those YK chillers need a start pulse and a stop pulse. Its a more of a latching switch type of action. You can add a start/stop relay...give it a run command and then pull the relay and it'll still run.

@building-automation 6 ай бұрын

Yes, I noticed that. I had to use a N.O/N.C relay. Normally open calls it on, and normally closed calls it off.

@building-automation 5 ай бұрын

Very interesting. That's the first time I've seen that setup on a chiller.

@HEFTYLEFTY303 5 ай бұрын

You can put that chiller in local mode so you can start stop right off the ov

@glennmcgurrin8397 5 ай бұрын

You may already know this, but if you are going to put in a switch, talk to IT about that, sometimes our switches will ge configured to only allow one device per port, you plug that switch in and two devices and it will either only allow the first or will shutdown the port entirely. They may also prefer to provide a switch to keep certain management and diagnostic functions available. Even if the port protection features to block unauthorized switches are not in use, it may still create headaches later when doing diagnostics or troubleshooting, IT generally wants to know what and where all the switches are and it's not just a power or control thing, it helps us do our job better, also in some compliance things we may need to know everything on the network.

@JohnnyJr396 5 ай бұрын

Some controllers provide a secondary network isolated from the primary. Just asking, how can a switch or any hardwired devices on secondary affect anything on the primary?

@building-automation 5 ай бұрын

Great advice, thanks!