8.5.1.5. Motor cycle rate of compressor

The motor cycle rate is calculated from the compressor running and idle time and compared with the allowed figure Al.

tI = 2,95 min tR = 4,56 min Motor output rating 22 kW Þ Al = 25

C = Cycles [1/h] tR = Running time of compressor [min] tI = Idle time of compressor [min] Approx. 8 cycles per hour is well below the allowed number for the 30 kW motor ( Al = 20 ). The compressed air receiver is of a good size. It could even be somewhat smaller because of the large reserve of motor cycles. Note If the exact compressed air consumption is not defined, 50% of the of the compressor FAD can be assumed as consumption when determining the motor cycle rate. In this case the idle and running times of the compressor are the same. This results in the maximum number of motor cycles.

---

[last chapter]
. . 8.5. Examples for compressor configuration
. . . . 8.5.1. Sample calculation for piston compressors
. . . . . . 8.5.1.1. Determining the maximum pressure pmax
. . . . . . 8.5.1.2. Determining compressor size
. . . . . . 8.5.1.3. Volume of the compressed air receiver
. . . . . . 8.5.1.4. Compressor cycle interval
. . . . . . 8.5.1.5. Motor cycle rate of compressor * You are here *
. . . . 8.5.2. Sample calculation for screw compressors
. . . . . . 8.5.2.1. Example for determining the maximum pressure pmax
. . . . . . 8.5.2.2. Determining compressor size
. . . . . . 8.5.2.3. Dimensioning the compressed air receiver
. . . . . . 8.5.2.4. Compressor cycle intervals
. . . . 8.5.3. Summary on compressor selection
[next chapter]