Software lag switch serial
Next, the relay board is wired into the PLC. This relay board has several expansion boards linked into it which are held together with an electrical ribbon. These, in turn, are wired into the white relay board at the top.
![software lag switch serial software lag switch serial](https://www.cisco.com/c/dam/en/us/support/docs/smb/switches/cisco-small-business-200-series-smart-switches/images/1135-1.png)
In the photo you can see wires from the various devices around the chiller, wired into a row of relays. This is just one of the many checks and procedures that we carry out during our maintenance visit.
Software lag switch serial software#
They can read incorrectly, so a sensor offset function is available in the software for adjustment. The program looks at these two sensors and using an algorithm, it calculates the loading requirement of the compressor. They usually read in kilo ohms which can be read on a standard multi meter. These are usually NTC (negative temperature coefficient) that is to say: if you hold one in between your fingers and warm it up- the resistance will start to drop off. The essential analogue inputs on a chiller are the Water In and the Water Out sensors. Contact Form Chiller Controls Analogue Inputs It needs to be periodically tested and adjusted at regular intervals. Serious system failure would result if this part is not maintained properly. This device detects a lack of flow in the water system. Components or the pressure relief valve can blow causing a catastrophic refrigerant leak. If the head pressure control mentioned above were to fail, this device would save the chiller from damage from excessive pressure in the system.
![software lag switch serial software lag switch serial](https://www.cisco.com/c/dam/en/us/support/docs/smb/switches/Cisco-Business-Switching/images/kmgmt2871-configuration-of-LAG-cbs220-image1.png)
Compressor and evaporator failure would result, so this device is set below the running pressure of the system, but high enough to offer protection. This protects the chiller from a low pressure condition. All of them have a volt signal out to them, which returns back to the panel. There are three essential digital inputs to the controls of any chiller. This is because all of the fans operate together- smoothly and reliably. Fan speed controllers are really good at extending the life of the fans. Solid state means that all the parts are electronic with no moving parts. This is according to the demand received by the transducer. It uses solid state thyristors to regulate the output to the fans. Fan Speed ControllerĤ15v on three phases are the input to the FSC. There is a minimum and a maximum value on the transducer, so the FSC is programmed to work out the pressure from the voltage.
![software lag switch serial software lag switch serial](https://i.ytimg.com/vi/M36L0CD2ka0/maxresdefault.jpg)
This gives a 0 to 5vdc control signal to the fan speed controller which is bolted to the frame. TransducerĪ transducer is fitted to the discharge pipe near to the compressor. The condenser pressure control is external and stand alone from the panel. He has targets to meet and wants to gauge the effect that our maintenance has in reducing his energy costs. The chillers in the photo are equipped with kilowatt hour meters because the customer wants to monitor their efficiency. They have N+1 redundancy built in, so one of two chillers will normally be in standby with the other one running. Chiller controls can be remotely operated and monitored, but in this article, we will be looking at chillers operating in local.Įach chiller has a panel where the lead or the lag chiller can be switched from.