A variable frequency speed control
branch circuit control device of a high-frequency vibrating motor relates to a building implement. The prior variable frequency speed control
branch circuit controldevice of the high-frequency vibrating motor usually adopts alternating-current
relay auxiliary contacts in series connection to realize
interlocking, wiring is troublesome, faults easily appear, andoverhauling is inconvenient; on the other hand, a triple-pole breaker is used for protecting the motor and the cost is high. Each
branch circuit control cabinet is provided with an
interlocking control circuit which comprises a testing circuit optionally in two-phase connection with the output end of a frequency converter, a make-and-break
control circuit connected with the testing circuit, and aself-locking circuit connected with the make-and-break
control circuit in parallel. The branch circuit control cabinet is provided with an alternating-current
contactor, the make-and-break control circuit is connected with the coil of the alternating-current
contactor in series, the self-locking circuit is provided with the normally
open contact of the alternating-current
contactor, and a dipolarbreaker is used for protecting the motor. The invention avoids the condition that two branch circuit control cabinets run synchronously, protects the frequency converter and reduces production cost, circuitry is simple, and maintenance is convenient.