Hello everyone,

I have a braking resistor with the number (6SL3201-0BE21-0AA0  140ohm and 4kw peak power), connected to G120C drive  6SL3210-1KE21-7AF1.

How do I know what the normal operation temperature? I have connected the temperature monitoring system of the resistor to the drive to be used as an external error.
I measured the temperature and it was up to 142C and I was worried. However, the temperature monitoring system did not trip. 

Your help is highly appreciated.

Hello,

142 °C ? It seems to me extreme... I do not think (my opinion) that the electronic components inside the resistor can work at that temperature... IF you are sure about that temperature I would reconsider the dimensioning of the resistor, probably it is too small, because having a 142°C hot component in an electrical cabinet is not very "safety friendly"...

Laugh ON:

If you are building stove, then in that case everything is fine.

Laugh OF

There is not specified the maximum operating temperature in the "catalog", so I hope that someone with a good experience might help you

I agree, this resistor is working too hard to be safe, this may also damage the drive.

The cut out is a 'Klixon' type bi metallic switch house within the resistor housing if this is not detecting overheat, is the resistor mounted as specified.

For this system to work, it may be possible to assemble more resistors arrange in series / parallel, to achieve greater power dissipation, whilst still maintaining the 140 Ohms at the drive.

I cannot find the max working temperature for the resistor, but I guess it would be less than 60Deg.c at the resistor, and not greater that 40Deg. c at the enclosure.

Tractor

Are the resistor connections correct??

Tractor

 Hello Tractor,

Thanks for your reply.
Yes, it is connected correctly. 

Then I should probably connect two couples of series connected resistors in parallel to get a higher capacity and keep the same resistance value 140ohm. Don't you agree?

Moreover, how do you know that the value of the resistance for this drive should be 140 ohm and not any other value? is it written somewhere? can it be some other value?

Tractor

Are the resistor connections correct??

Tractor

Hi Mohamad.

You have a braking resistor with the number (6SL3201-0BE21-0AA0  140 Ohm and 4kw peak power), connected to G120C drive  6SL3210-1KE21-7AF1, (5.5kW, 400Volt 3 phase). 

The recommended resistor for this drive is 6SL3201-0BE21-8AA0, 75 Ohms, 7.5kW pk power, the resistor you have installed is not the correct unit.

This may be the reason it is overheating?

Tractor

Hi Tractor,

It makes sense that I need a resistor with higher power peak (7.5 kw) and that is must probably what I should do. However, I am not sure whether 75 ohms is good for my drive. How can I figure out what the right resistor value for my drive? 

Tractor

Hi Mohamad.

You have a braking resistor with the number (6SL3201-0BE21-0AA0  140 Ohm and 4kw peak power), connected to G120C drive  6SL3210-1KE21-7AF1, (5.5kW, 400Volt 3 phase). 

The recommended resistor for this drive is 6SL3201-0BE21-8AA0, 75 Ohms, 7.5kW pk power, the resistor you have installed is not the correct unit.

This may be the reason it is overheating?

Tractor

The value 75 Ohms is specified in the catalogue for that drive. You can change the power rating of the resistor by connecting in parallel / series, but the resistance is fixed at 75 Ohms.

Tractor

Let me clarify what they mean by parallel/series:

---/\/\/\/\/--- = 75Ω  Single Braking Resistor

              75Ω             75Ω
   ,-------/\/\/\/\--------/\/\/\/\---,
---|                                  |---  = 75Ω Parallel/Series
   '-------/\/\/\/\--------/\/\/\/\---'
              75Ω             75Ω

Parallel series will have much more power handling capacity if the same part # is used for the single as is used in the parallel/series.

Tractor

The value 75 Ohms is specified in the catalogue for that drive. You can change the power rating of the resistor by connecting in parallel / series, but the resistance is fixed at 75 Ohms.

Tractor

Have a similar query for the Siemens DBR . All the Siemens DBR have an integrated Thermostatic switch which operates at high temperature. Do we have details at what temperature does this thermostatic switch operate for the DBR 6SL3201-0BE23-8AA0.