Carrier 09RH specifications

When a capacity safety factor is used, the compressor is selected at its maximum speed to handle design load plus safe- ty factor. Multiplying factors for non-standard speeds are shown in Fig. 20.

Whether or not added capacity offered by the safety factor is incorporated at once is a matter of judgment. If it is, then the compressor will be operated at maximum speed at the start and any excess capacity achieved will be reflected in faster

pulldowns or lower temperatures. It is also a good practice to drive the machine at a speed that will provide slightly more rated capacity than is required by design load. Additional speed-up available will then constitute reserve capacity in the event it is needed. Motors should be sized to run the compres- sor at maximum speed to forestall any motor changes, should this maximum compressor speed be required in the future.

Fig. 18 — Flow Diagrams for Common Multistage Systems

(Not to be used as Piping Diagrams)

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