1. Fault symptoms

In September 2014, in the process of discharging material in the external circulation of a certain fly ash steel plate warehouse project, the dust collecting motor on the top of the warehouse often failed and tripped, resulting in the dust collecting device on the top of the warehouse could not work. The feedback from the field staff is as follows.

(1) Dust collector in the starting process of dust motor failure trip occasionally.

(2) The material in the steel plate warehouse runs for about 1 ~ 2h with external circulation, and the dust collecting motor fails and trips.

(3) When the dust collecting motor fails to trip, the action current displayed by the motor protector is 40A.

(4) The field dust collector is PPCS326, and the main data on its nameplate are as follows: Centrifugal fan is 9268D, with flow rate of 8792 ~ 11320 m3/h and full pressure of 3834 ~ 3638 Pa;