Think of a master controller as a sort of traffic cop for a busy intersection, coordinating compressors instead of cars. It provides the necessary communication and orchestration required to ensure that every compressor is working in concert with its counterparts. Master controllers have been on the market for years, many of them are nothing more than a glorified sequencer that turn compressors on and off in a predetermined sequence. Don’t be confused, they are not the same. A master controller that runs on logic has the capability to select the right compressor based on demand whereas a simple sequencer only starts the next compressor in the sequence. Both have the ability to target a single pressure reading, by a single utilizing system pressure transducer, but a master controller will ensure the best multiple compressor configuration is always enacted.
The differences between a sequencer and a master controller with “true load-sharing” capabilities are vast. True load-sharing is powerful. It has the capability to have compressors of different capacities work together to meet varying demand. For example, if the plant engages in a process that requires a large demand of compressed air, say the rate-of-change in the compressed air header decays rapidly and an additional compressor is required to be brought online, a true load-sharing master controller with feedforward algorithms will automatically select the next available compressor that specifically fits that profile and bring it into the system. This key feature ensures that the optimal compressors are always selected. Selecting the wrong units to come online most likely will lead to short cycling, further adding to system instability and inefficiency. A robust control scheme would be to run the minimum compressors necessary, at their peak efficiency (usually 100%), with one compressor trimming at any given time.
Master controllers also provide a level of reliability through redundancy in a fail-over scenario. In the situation where a compressor fails unexpectedly, the master controller doesn’t skip a beat, it will seamlessly bring on the next appropriate compressor without the need of intervention from plant personnel.
A key take away – Many suppliers will try to sell you a pre-engineered system and make the customer’s needs fit their scope of supply. Case Controls develops solutions to match the plant’s needs to maximize efficiency.
To learn more about out custom master controller solutions, contact us today.