Hello,

Is it possible to connect external braking module to PM240-2  with any CU(G120 OR S120)?

To be more specific I have a existing master drive system of 75KW OP and a external braking module of 170kw and 2ohm 170KW braking resistor. This model is to be replaced with PM240-2 75KW high overload which has 77kw peak braking power and 7.1ohm resistance. Can we use the existing external braking module with the PM240-2. Or will the PM240-2  alone take care of the braking need. The application is hoist control.

Technology Team

Hello,

there is no external braking unit released for PM240-2.

[snip]

It would be possible to use braking resistor with higher energy capacity for PM240-2.

Sinamics PM240-2 braking chopper duty cycle update

https://support.industry.siemens.com/cs/ww/en/view/109760188

 Thank you for the reply

But is it possible? ie we use braking module of s120 or any 3rd party.

Technology Team

Hello,

please check with the update for braking chopper cycles, if the there given values and load cycles fit to your requirement.

The PM240-2 3AC 400V 75 kW HO has a peak braking power of 90 kW (for 120 s in a 240 s cycle) or 45 kW rated (continuous) braking power, if you use a suitable resistor with 7.1 ohm.

The use of an external braking chopper is not released and so you would loose your warranty (specially as you would need to modify the PM240-2 housing at some newer modules in frames sizes F to G, which have no accessible DC terminals any more).

If the braking power is not sufficient, you need to take a larger PM240-2 FSF, e.g. the 110 kW (HO) provides 132 kW peak power and 66 kW continuously with a 5 ohm resistors.

 Actually the said materials are already avaliable. The selection was done by overlooking the braking module.

We have unboxed the drive and saw what you said. The DCP and DCN terminals are not provided.

We are looking into getting a higher power VFD.

Suppose in a lower rating which has DCP and DCN terminals can we use external braking module. Just curious.