Value of the power dissipated by braking resistor 6SL3201-0BE21-8AA0

Ciao a tt, non riesco a trovare il valore della potenza dissipata dalla resistenza di frenatura 6SL3201-0BE21-8AA0. Esiste un dato certo ?

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Split from Braking resistor temperature.

Hello ambrogio_PR,

Please try to discuss your question in English language. This is an international community and we try to focus on one language. Posting in English will help to generate more replies to your question.

This is the translation of your post:

ambrogio_PR

Hello tt, I can't find the value of the power dissipated by the braking resistor 6SL3201-0BE21-8AA0. Is there a certain figure?

Kind regards, Moderator_Lan

Grazie delle informazioni.

Questi sono i dati forniti dal data sheet SINAMICS resistenza di frenatura R=75 Ohm P_continua=375 W P_max=7500W/12s/5% cosa devo tenere presente per una veridifica della sovratemperatura del quadro?

Di solito le resistenti di frenatura s'installano fuori dal quadro ma è opportuno prevederla all'interno del quadro (800x2100x500) e fare una somma della potenza dissipata di tutti i componenti elettrici interni al quadro. Secondo voi, quanti W di dissipazione eroga la resistenza di frenatura? Circa 400 W?

Hello ambrogio_PR,

Please try to discuss your question in English language. This is an international community and we try to focus on one language. Posting in English will help to generate more replies to your question.

This is the translation of your post:

ambrogio_PR

Thanks for the information.

This is the data provided by the SINAMICS data sheet

braking resistor R=75 Ohm P_continua=375 W P_max=7500W/12s/5%

what should I keep in mind for a check of the overtemperature of the panel?

Usually the braking resistors are installed outside the panel but it is advisable to provide it inside the panel (800x2100x500) and make a sum of the dissipated power of all the electrical components inside the panel.

In your opinion, how many W of dissipation does the braking resistor provide?About 400 W?

Kind regards, Moderator_Lan

Some people do not realize their posts are not coming through in the forums default language (English in this conference).

Translation

Thanks for the information.

These are the data provided by the SINAMICS data sheet braking resistance R=75 Ohm P_continua=375 W P_max=7500W/12s/5% what do I have to keep in mind for a verification of the overtemperature of the panel?

Usually the braking resistors are installed outside the panel but it is advisable to provide it inside the panel (800x2100x500) and make a sum of the dissipated power of all the electrical components inside the panel. In your opinion, how many W of dissipation does the braking resistor deliver? About 400 W?

If it were me and I had to provide any type of warranty, I would use the maximum(375W, 7500W @ 5%, and 375W @ 95%).  I do not have to do the math to know which calculation I would support.

You also need to direct air across the braking resistor, install it in the proper orientation (vertical, horizontal, or something else) according to datasheet, and installation instructions.  Otherwise, the power dissipation can continually raise the resistor temperature beyond its design specifications and it will fail or at least significantly reduce its useful life.

That said, you are the designer / engineer with the capability to down-size the power dissipation because of intimate knowledge of the process / system / drive / motor / and other constraints that may be placed upon the motor / drive that lets you know you only need to account for worst-case (like during commissioning, setup, or very short-term tests or troubleshooting.  Then you _can_ design in for less cooling. This does however but the burden on you to never allow the system to operate outside whatever design envelope you've designed in.

It's always a balancing act here.  Add max spec cooling which is considerably more cooling than necessary for the system, and battle with the potential for condensation.  Or, use your engineering knowledge, system modeling calculations (maths), and reduce the cooling.

And, be sure to run the over-temp signal to something, like the VFD, or to a relay so you can distribute the over-temp signal to the VFD, PLC, and perhaps jump around any cooling device's thermostat or enable signal so it turns on cooling immediately if the resistor overheats. 

Just a few ideas to think about, some or all of which may not be useful to you in your specific application needs.