Nice tutorial video love it. Just want to ask if during time of DC injection into the 2wire of motor, the 3phase supply is momentarily disconnected untill motor will completely bring to stop position. Thank you for the answer.❤
So, the example that comes to mind to me is traction elevators.....Is this the "new way" to do slowdown, vs. MG drives that dump it off as heat thru resistors?
A braking transistor in a drive will act as a method of diverting excess energy returning to the drive from a motoring operation to a braking resistor. A braking resistor is external to a drive and is the component that will dissipate excess energy as heat. This will save your drive from excess energy which can cause damage to the drive. However, this video is discussing DC injection braking. The major concern here is excess motor heating. This is to decelerate a load quickly, but not meant to hold a load at zero position for any length of time. You need to make sure your motor will handle the excess heat generated from injection braking. If you have further questions you can contact us (kebamerica.com - if you are in North America) or your local KEB Representative: www.keb.co.uk/company/company-group
@@KEBAmerica Thanks alot If my application don't require this method of braking there is no danger to the drive with this built in braking unit With another mean the drive with built in braking transistor no need for connect resistor to save the drive if I don't use this method of braking
Hi guys, great video. Now, I would like you to answer a couple of questions. Although from outward appearances the braking cycle seems almost instantaneous, in fact, with DCib there is almost no braking torque in the initial portion of the cycle instead it all comes in a great big rush at the end. Could you explain the reason for this braking-effect delay, i.e. why it takes such a large proportion of cycle time for the negative torque to build? (Assuming standard squirrel-cage induction motors) Also, orthodox DCib implementations utilise timer relays to terminate the braking cycle. This is a very crude method. Better to use the actual shaft rotational stopping point. Can you suggest any clever feedback techniques employing signal outputs from the motor windings themselves to operate the drop-out braking contactor? Thanks.
Hello i have variable frequency motor and stops by dc braking to reach 0 speed position .. i just want to know how inverter applies dc voltage through 3 phases ? .. does it apply dc to one of them ? .. and is it like pulses from the inverter or constant dc to the motor
The main parameter option to reduce heating is to reduce the maximum output voltage. There are also parameter settings for the DC braking time and start speed, both of which could affect motor heating. We hope this helps.
3:26 ...no additional components...don't you sometimes need a larger braking resistor depending on how big the motor/load is and how fast you want to stop it? I see other videos where they attach gigantic external braking resistors.
Yes... Did one today actually... I'm an industrial service electrician. Today I worked on a system at an asphalt mixing plant with a motor name plate that read 250HP 460VOLTS 270AMPS 3.0 OHMS ...
Hello sir, I am very helpful with your information but, can I see directly the dc source that is short circuited with the stator coil? how does the star-delta termination affect the injection? and the dc source is fed to the 2 stator windings, how is the effect of one of the windings that is not connected to the DC source? can you explain how to calculate the maximum heat in the stator winding so that no damage occurs to the AC motor thank you, I really hope for your help
You can read more about DC braking here: www.kebamerica.com/blog/dc-injection-braking/ If you want more information for a specific application you can contact us or you can find other places to learn about DC braking online.
Dear i have 45 kw vfd and there are 4 motors of 11kw each connected in parallel with this vfd,now i want to stop these motor by DC braking,please tell me how much DC current should be injected and how much time?
Nice video guys! I have a question about DC injection braking. Does a typical DC injection brake care about the frequency of its AC input or just the voltage? E.g. do they care about 50Hz or 60Hz as long as the voltage is as expected? I believe it shouldn't matter because the AC voltage is going to be rectified to DC but thought I'd ask some experts! :-)
You are correct. Input frequency doesn’t matter. The output DC voltage has a range of 0-25.5% and is a parameter setting. Thanks for the question. If you have questions about purchasing KEB products for an application feel free to contact us! www.kebamerica.com/contact
You said apply dc only for small time period, how much exactly? Does all drives support dc break? Is there restrictions for a size of drive/motor? Does soft starters/stop support this? Many thanks
Specifics for duration/amount/etc. are all application dependent. Not all drives support DC braking. No restrictions on the size of the drive that could utilize this function. I am not aware of any soft starters that would offer this function. Thanks again for your comments!
This article should give you a few things to think about when selecting a braking resistor: www.kebamerica.com/blog/when-and-how-should-i-select-a-braking-resistor/
I used this dive in an elevator it gives me an error displaying like this (F1 68 ) I don't have any manual for this drive It is vacon nxl00235c2h1sss0000. I need some technical support if don't mind.
You should contact your elevator controller manufacturer first. Vacon is a different VFD brand. We cannot help you with your questions regarding this product. You can search for this Vacon drive online and find a manual. Have a good day.
You can find the parameters for DC Injection braking at the bottom of our blog post on the subject. kebblog.com/dc-injection-braking/ Scroll down to the last few sections of the article and you'll find an image with the parameters "Pn38" - "Pn42". Let me know if this answers your question. Thanks for the comment!
Have you contacted your machine manufacturer? That should be your first step. If they cannot provide a solution then you can find a local KEB representative here: www.keb.co.uk/contact/contact-worldwide
The brake engaging is entirely unrelated to DC injection braking. A couple things to check is the power supply to the brake and possibly the airgap of the brake. For more information contact your machine manufacturer, supplier or a local KEB Representative by phone or email. Find one here: www.keb.co.uk/company/representatives-agencies
We have a video for uploading and downloading parameters here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-rZiK1_NE5kg.html And here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-dzwU3wTwYys.html
As said in the video, you can use DC braking to bring a load to zero speed, but you should not use this type of braking to hold a load. You will need some type of brake (like a permanent magnet or spring applied brake) if you need to hold a load for any length of time. If you apply DC braking for too long, you risk overheating the motor. The stopping energy is transferred to heat and too much heat is bad for any motor. :) You can use DC braking in intervals. However, keep an eye on the motor temperature so you don't ruin your motor. Read more about Motor Thermal Protection here: kebblog.com/motor-thermal-protection/ Let us know if you have any other questions. Thanks for watching!
Hello Julio, Are you asking if we have drives for hydraulic elevators? Or are you saying we need to offer drives for hydraulic applications? I'm confused.
