Pulse frequencies of the brakes

In the case of brakes operated with AC voltage, make sure the connection type designated by the manufacturer is applied correctly during the brake connection. The following types are distinguished:

  • Cut-off in the AC circuit (AC cut-off) with normal application time
  • Cut-off in the AC circuit and the DC circuit (AC/DC cut-off) with shortened application time

The correct cut-off type must be ensured through appropriate wiring. Certain brake control systems from SEW-EURODRIVE realize the same cut-off in the DC circuit and in the AC circuit via integrated switching relays (e.g. BMP1.5), or via mounted switching relays (e.g. BSR or BUR).

Observe the following points to prevent a delayed application or an unintended release of the brake:

  • When configuring the system, take into account the desired shutdown method and, in particular, the effects on the expected stopping distance.
  • For hoists and hoist-like applications, only use the faster AC- and DC‑side shutdown.
  • If it is unclear whether the application is a hoist-like application, contact SEW‑EURODRIVE.
  • Make sure that the configured connection type (AC or AC/DC) is implemented correctly during startup, regardless of the type of application.

The connection type is specified on the included wiring diagrams by a pictogram.

For brakes operated with a DC voltage, a cut-off only in the DC circuit (DC shutdown) is always performed due to the operating principle. This DC cut-off has the same application time as the AC-DC cut-off method. The selected connection type must be taken into account in the project planning using the variable t2 according to the specification in Mechanical project planning.