Typically, in North America we have 2 types of condensing pressure controls for industrial refrigeration plants.
1. Pressurestats. Each pump or fan controlled by its own pressurestat. This is not perfect control but it is cheap $1,000-2,000.
2. PLC. Condensing pressure control is part of the PLC, but this PLC is not cheap $30,000 - 100,000.
Does anybody use another approach to control condensing pressure which have costs $5,000-10,000?