Tractor

DC injection braking applied DC current to the motor coils as you have configured at 100%, from 80Hz, for 10 seconds.

With Dc braking there is no ramp down, it will stop as quickly as possible.

If you need a ramp down remove DC Braking, and configure the ramp down using P1121, set in seconds.

Tractor

Hi Tractor,

I have a similar issue whereby I am using a V20 and a dynamic braking module with a braking resistor attached. Unless I change the ramp time to be very long and therefore the hoist is very slow, the inverter trips on overvoltage when lowering a load with the hoist. Should the resistor just work providing it is wired correctly? It is not getting hot so does not seem to be working, and no green active light is showing when the hoist is lowering, just trips out.

Thank you

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Split from DC BRAKING in connection macro Cn005.

Several ways to correct this problem.

Easiest is to replace the single braking resistor with a network of identical braking resistors to quadruple the ramp down power handling of the dynamic braking system.

There are 3rd party companies that offer brake resistor networks to meet your specific needs.

For example, you tell them the Siemens part # for the brake you have, they come back with a part that has 4 equivalent brakes in there in a series/parallel arrangement so the overall resistance is the same, but it can handle 4x the power during decel.

And if that is not enough, they offer 4x4x (16x) where they build for of those series/parallel deals, and series/parallel those.  If your system maxed those out, you would probably burn something else up as that's a LOT of dynamic braking power - very expensive and very large.

More expensive option is to replace the V20 with a S120 regenerative braking setup with ALM/AIM/Motor module.  Regen braking offers more decel capacity than a single DC brake.

Much more expensive.  Much more back-panel space.  Much more complicated to build, commission and integrate.  When I say much more, it's because you would have to squeeze 5x more things in the same space, so it gets expensive wasting time dealing with the solution a Siemens partner probably should have / would have suggested for your application.

Mattleo

Tractor

DC injection braking applied DC current to the motor coils as you have configured at 100%, from 80Hz, for 10 seconds.

With Dc braking there is no ramp down, it will stop as quickly as possible.

If you need a ramp down remove DC Braking, and configure the ramp down using P1121, set in seconds.

Tractor

Hi Tractor,

I have a similar issue whereby I am using a V20 and a dynamic braking module with a braking resistor attached. Unless I change the ramp time to be very long and therefore the hoist is very slow, the inverter trips on overvoltage when lowering a load with the hoist. Should the resistor just work providing it is wired correctly? It is not getting hot so does not seem to be working, and no green active light is showing when the hoist is lowering, just trips out.

Thank you

------------------------------------------------------------------------------------------
Split from DC BRAKING in connection macro Cn005.

I guess it is not working?

If all the connections are correct?

Status led (green) should show during braking?

Power (yellow) must be on.

P 1237 sets the duty cycle, make this 5 for 100% duty,

Or for Frame size A, B or C, set this on the 'duty cycle control knob', 100%.

Is the resistor value correct, Frame size A to C, 56 Ohms, D 27 Ohms?

Tractor