Skip to Content

SiePortal

The integrated platform for your product selection, buying and support workflow - bringing together Industry Mall and Online Support.

SiePortalDeutsch

Search

Home
Support Support
{{(apiData.Support | filter:{'rank':1}:true)[0].title}} Support
- Menu temporary not available
- Menu temporary not available
- Menue temporary not available
- {{item.title}}

Products & Services
- Menu temporary not available
- Menue temporary not available
- {{item.title}}
Support Support
{{(apiData.Support | filter:{'rank':1}:true)[0].title}} Support
- Menu temporary not available
- Menue temporary not available
- {{item.title}}
MySiePortal MySiePortal
{{(apiData.MySiePortal | filter:{'rank':1}:true)[0].title}} MySiePortal
- Menu temporary not available
- Menue temporary not available
- {{item.title}}
Cart ({{apiData.CartCount}})

Navigation

Controlled stopping of axes during power failure

Created by: Genn123 at: 10/4/2021 11:42 AM (6 Replies)

Rating (1)

Thanks 0

7 Entries

10/4/2021 11:42 AM	Rate (0)
Genn123 Bronze Member Joined: 8/21/2014 Last visit: 7/31/2025 Posts: 142 Rating: (1)	Hi all, We want to stop the moving axes in a controlled manner(decelerated stop) when the power stops. We have a spindle axis which will be moving at rpm with a heavy load on top. In case of sudden power failure we want to stop the axis in a decelerated manner to protect the mechanical couplings and structures. How it can be done. We thought not to use UPS since the backup time is only around 3s. Can we use capacitor module to provide the backup power for the safe stop?. What is the usual practice?

Suggestion To thank Quote Answer

10/5/2021 6:25 AM	Rate (0)
𝐤β Silver Member Joined: 7/30/2012 Last visit: 1/3/2026 Posts: 335 Rating: (13)	Hello, Maybe you can try Extended stop and retract function in S120(ESR)

Suggestion To thank Quote Answer

10/5/2021 8:28 AM	Rate (0)
Davinator Gold Member Joined: 1/4/2013 Last visit: 1/13/2026 Posts: 1195 Rating: (106)	WIth power failure it is hard to brake an axis using deceleration since you need power to control the motor during this stage. UPS gives you the 24 V but nobody will keep the DCBUS up. So in my opinion (maybe an expert might say different) this is not possible
	Searching for Siemens used/new equipments ? Take a look here : https://www.ravettiautomation.com
Suggestion To thank Quote Answer

10/5/2021 10:50 PM	Rate (0)
jacek d Platinum Member Joined: 9/23/2005 Last visit: 1/16/2026 Posts: 5155 Rating: (772)	General advice, you must detect power failure but not disable pulses then brake hard enough to pump up the DC bus (but not too hard so the DC bus won't get over-voltage, unless you have braking module). If you use Safety Integrated you must ensure pulses won't be disabled, i.e. no STO activated.
	Regards, Jacek What is confusing you is the fact that you never see a number but always its digit representation. So you end up thinking that the number is the representation. - Andrej Bauer Any claims against me - based on whatever legal reason - resulting from the use of any code and/or ideas presented on this forum shall be excluded. #StayWithUkraine
Suggestion To thank Quote Answer

10/7/2021 7:00 AM	Rate (0)
Genn123 Bronze Member Joined: 8/21/2014 Last visit: 7/31/2025 Posts: 142 Rating: (1)	Correct me if i am wrong. If we place a capacitor module, will that have some stored energy to keep up the DC bus voltage for some moment of time?. say 1/2s?

Suggestion To thank Quote Answer

10/7/2021 8:43 AM	Rate (1)
Manfred Posts: 156 Rating: (17)	The axis should be braked specifically (electrically) in the event of a power failure. For this purpose, the 24 VDC electronics supply of the Sinamics must be maintained long enough after the power failure. Either this is realized with external storage modules or the energy stored in the DC link is used to generate the 24 V via a CSM. To ensure that the DC link contains sufficient energy, a capacitor module should be connected. After the mains failure has been detected, braking must be performed with a ramp that is as sharp as possible. To prevent the drive from switching off in this state with error "overvoltage", a braking unit with braking resistor must still be connected to the DC link. The function is described in the function manual chapter 12.4. https://support.industry.siemens.com/cs/de/en/view/109781535 Regards Manfred
Manfred Posts: 156 Rating: (17)	Last edited by: Jen_Moderator at: 10/07/2021 11:17:45 Edited text for better reading.
Suggestion To thank Quote Answer

10/14/2021 2:44 PM	Rate (0)
Genn123 Bronze Member Joined: 8/21/2014 Last visit: 7/31/2025 Posts: 142 Rating: (1)	We are using Active line module in our project. Do we need braking module in that case? How this control supply module works? Is that taking the DC link voltage(600VDC) which is available(which will be available during braking/capacitor module) in the DC link to supply 24V? If we are using a seperate UPS line, do we need CSM? We can go ahead without capacitor module, only the electronics needs to be powered?(We can use a seperate UPS for that) Nothing else is needed. Is it so?

Suggestion To thank Quote Answer

|

Share this page:

Share this page on...

Follow us on