Opto 22 groov RIO & Ignition HVAC Management
In many manufacturing operations, the supporting process systems are equally important as the production equipment itself. For a Corso Systems’ customer, this meant they needed to double their compressed air capacity to support their growing number of Automated CNC Cells.
A common problem with industrial air compressors is that they generate a lot of heat when compressing the large amount of air that production requires. Keeping these units cool in a medium to large manufacturing plant can be a costly challenge.
For this particular use case, the goal was to remove hot air before it could overcome (and shut down) the air compressors. By managing the room’s temperature, the air compressors’ internal settings wouldn’t need to shut down the compressors to prevent overheating. When a compressor shuts down, compressed air is lost and production stops until the compressor comes back online.
Originally, the system used an always-on VFD that could handle a single air compressor unit—but not the additional units required for future expansion.
We worked with the customer’s HVAC team to spec out additional VFDs, along with cooling dampers to help maintain proper airflow based on indoor and outdoor temperatures. This would keep the air compressors during the summer, but also will keeping the temperature in the room bearable in the winter (when outside temperature can dip into the negative double digits degrees Fahrenheit).
Solution
Inductive Automation’s Ignition Platform
Opto 22 groov RIO for I/O, device communications, and PLC logic
Schneider Electric Altivar VFDs
Belimo Air Damper Actuators
Quincy Air Compressors
Codesys PLC Runtime Engine
Honeywell Temperature Sensors
SQL Server Database
Implementation Summary
Corso Systems worked closely with the customer’s production and HVAC teams. With their knowledge of the original system and our experience working with HVAC systems across many industries and applications, we created a new design which can scale as their compressed air needs grow.
First, two sets of dampers were installed in each window adjacent to each air compressor. Two dampers per window allows for finer airflow control into the room based on inside and outside temperature inside. Secondly, a recirculation damper was installed in each air compressors’ exhaust ducts to allow the systems to recirculate air when the outside temperature is lower than the setpoint. Next, a roof mounted damper was installed for each compressor for releasing hot air. Finally, another VFD was installed with an additional compressor unit to double the overall size of the system.
While the custoemr’s typical choice is Allen Bradley PLC hardware, the current lead times were prohibitive. So, we decided to use Opto 22’s groov RIO platform instead. This hardware choice also allowed us to have fully featured I/O devices at a low price point for integrating all of the field signals. Additionally, the Opto 22 groov RIO gave us access to Node RED and the Codesys runtime for controlling the system and handling communications with the VFDs.
Corso Systems leveraged the Ignition SCADA platform’s Perspective Module to give operators mobile device and PC-based access to the system. Compared to the old system, this improved electronic access will save operators the time and effort of walking to the compressor room multiple times a day (which often adds up to a mile a day or more) to make sure everything is still running smoothly.
The indoor and outdoor temperature sensors were installed and wired into the groov RIOs along with the VFDs and damper signals. Corso Systems programmed everything in Node RED and Codesys, and deployed the system in a single day—which then kept everything running without operator intervention on an unseasonably warm 92 °F day in June!
Project Innovations
Codesys Runtime Engine on a groov RIO
At the time of the project’s inception, the Codesys Runtime Engine had just been added to the groov RIO lineup. Our project was likely the first deployed field implementation of Codesys on a RIO!
Codesys managed all of the control logic of the system. Node RED handled the data to/from the VFDs using a Modbus RTU library which converts it to OPC-UA and sends it to the Codesys Runtime Engine’s built-in OPC-UA server. Then, everything was dislayed in Ignition with the Perspective Module which provided PC-based and mobile device access.
Modbus RTU to OPC-UA Communication Translation with Node RED
Normally, we would use Allen Bradley VFDs, but again the lead times were measured in quarters instead of days. So, we chose the Schneider Electric Altivar platform instead. Our original plan was to use the Ethernet-IP integration in the Codesys Runtime Engine to communicate with the drives directly, however the Schneider platform only supported Modbus RTU. Fortunately, we were still able to communicate using a USB-to-RS485 converter on each RIO device with Node RED handling communications.
Node RED managed communicating with the drives for status updates, speed feedback, and alarms, then converted this data to OPC-UA to get it into the Codesys Engine for control.
Node RED also handled getting data from Codesys back to the VFDs for start/stop commands, and speed adjustments.
Results
Corso Systems worked with the customer to rapidly develop, deploy, and commission a control system to meet their compressor room HVAC management needs before the summer heat took hold.
As always, we combined our expertise with the experience of everyone on the project team from the customer side. This allowed us to design and deploy an optimal solution without much need for troubleshooting or re-working the design once the rubber met the road.
The system was deployed well ahead of the first hot days of summer, and managed the temperature in the room beautifully. The compressor kept working during the course of one of the hottest weeks on record and prevented production impacts that had plagued the facility the previous year.
