Patent attributes
A refrigeration system includes a medium temperature subsystem circulating a coolant in a closed loop between at least one medium temperature chiller and at least one medium temperature load and at least one cascade heat exchanger, and a low temperature subsystem circulating a coolant in a closed loop between at least one low temperature chiller and at least one low temperature load. A cooling circuit is provided for circulating a coolant and includes a first pump and a second pump and a fluid cooler and a valve, and interfaces with the medium temperature chiller and the low temperature chiller. The valve is movable to a closed position to define a first flow path and a second flow path, where the first flow path includes the first pump and the medium temperature chiller and fluid cooler, and the second flow path including the second pump and the low temperature chiller and the cascade heat exchanger.