What is a Soft Starter? (For Absolute Beginners)
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- čas přidán 19. 06. 2024
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In this video, we are going to discuss the “Soft Starter” method amongst all other motor starting methods and we will cover the rest of methods in future videos.
Since Electric Motors often require large amounts of electricity during their accelerating to the nominal speed, a Soft Starter can be used to limit the surge of current known as “inrush current” and torque of the electric motors, resulting in a safer, smoother and gradual start-up.
Soft starters will protect your electric motor from possible damage and at the same time extend the lifespan of your electric motor and the whole system by declining the heating caused by frequent start/stops, reducing the mechanical stress on the motor, its shaft, and reducing the electrodynamic stresses on the power cables.
One example of this is an Air Scrubber or Dust Collector.
These will have large fans inside.
In this application, it will take some time to get the fan moving but once the fan is moving the current and torque load on the motor is reduced.
In the system, the fan will pull air into filters where dust particles are collected. Then the clean air is pushed back to the factory.
Water supply applications are another great use for soft starters.
When using pumps in a process you have to bring them up slowly. If not you will cause pressure surges in the water system that could lead to dangerous conditions.
The soft starter can be controlled either by a direct start/stop wiring or, it can be controlled over ethernet. Both control methods have their advantages and disadvantages.
Direct start/stop signals would not require a PLC. They would be less expensive. Using ethernet control, a PLC is required.
This will allow there to be feedback, which will give adjustable control and monitoring capabilities.
The main component of a soft starter is a Triac which is designed to limit the applied voltage to the motor.
Triac consists of two back-to-back Thyristors or SCRs. When an internal pulse is applied to its gate it allows current to flow which then sends current out to our motor.
The pulses are sent based on ramp time so the current will be slowly applied to the motor. This will allow our motor to start slowly reducing torque and inrush current.
When the motor reaches full speed the soft starter and DOL work the same. The difference is how they act while getting to full speed.
When comparing the voltage between a DOL starter versus a Soft Starter, we can see that there is a direct in rush of voltage on the DOL where the Soft Starter takes more time to get up to full voltage.
The current is more regulated using a soft starter. With a DOL there will be larger spikes in current as the motor starts.
With a soft starter, the time the motor gets us to speed is slower and more controlled.
Our Air Scrubber fan will be driven by a motor using belts and pulleys. Using a DOL can cause the belts to slip and wear.
With our water supply example, the DOL will cause pressure surges on the water lines. This can cause excessive wear which could lead to line breaks.
There are also electrical effects that we want to avoid by using a soft starter. The heavy current surges that a DOL can cause, can burn out contacts and motors.
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Congratulations the best industrial chanel in youtube.
Thanks a lot for your support!
I agree
I'm planning a whole house backup generator which includes running my 3 ton Air Conditioner. The problem WAS my AC was blowing my budget because it would require an 8000 watt minimum generator to handle the initial startup of the unit. I found this soft starter and installed it on my AC (took about 10min.) and now I can run my entire house on a 3500 watt generator. Saved me $$
The love and appreciation for the team that makes and delivers these videos can be difficult to really convey because it’s highly regarded, so as well is the person narrating the videos. I worked for years as a Tech in the Utility Plant Environment around many equipment with Soft-starters as well VFD’s and never quite understanding properly quite how they worked in a properly explained way like explained by RealPars. I feel so much appreciation from the care taken to make these videos in explanation in demystifying industrial automation understanding. I’m so much smarter because I’m here!
Thats an amazing comment, Ardent! Thanks a lot!
😂🍎🍎
Technology is fascinating. I am just a young adult who is interested in science and technology, and was hoping that there was a device that can reduce flickering of the lights when the air conditioning starts (current inrush). Apparently, someone invented it: the soft starter, and RealPars explained it so well (visual learner here). 10/10 good video. :)
*Would be nice if air conditioners, dehumidifiers and fridges could gently start up. Sadly, domestic air conditioners typically don't have enough inertia to necessitate a soft start system, which can cost a lot of money. Also, the flicker of the lights occur for just 1/10th of a second. Thankfully, most my bulbs are LED, so only one or two incandescents flicker. Also, variable stage air-conditioning does exist, and they use similar motor ramp-ups to alternating current soft starts to reduce initial energy consumption.
The pedagogical approach in your videos is exemplary
I am learning a lot watchig RealPars videos. No teacher explains the concepts , components and basic theories as this channel. Thanks a million!
Hey Fernando,
Thanks a lot for your kind compliment! We are always extremely happy to hear such positive feedback! If you ever have any questions, feel free to reach out to us.
Happy learning!
Very informative videos from RealPars i am definetly learning a lot and get better understanding on the things i work with daily
thanks realpars you're my favorite education channel on CZcams ❤❤❤
Happy to hear that, Muhammad!
One of the best channel to learn
The graphics and the explanation used to explain this is is i guess the easiest to understand and apply ... Love this platform 👍
Glad you like them!
Your videos are really high quality, thanks for the upload, you're a very nice person!
Great to hear that! Thanks a lot!
Bah. This was clearly a Siemens advertisement!
Appreciating the lesson. Thank you
Glad it was helpful!
It is a professional explaining and clearly. Thank you very much for your efforts
You are very welcome, Mohamed!
Thank you RealPars !!! You are the best !!!
Thank you!
Excellent video! Thank you for sharing.
Thank you!
Thank you very much , I am new at this, I enjoy the explanations and graphics you share.
Happy to hear that, Francois!
Thanx Realpars for great videos. This Is Real Pars ...
You are very welcome!
First time subscriber, im really impressed by your videos and explanations. Straight to the point. Bravo👏🏽👏🏽👏🏽.
Thank you 🙏.
Thanks a lot for your kind compliment! We are always extremely happy to hear such positive feedback! If you ever have any questions, feel free to reach out to us.
Happy learning!
Very informative..
Thanks for your clear explanation.
Amazing! Thanks for sharing, Naresh!
That is easy to get more knowledge. Really receptive and visual images. Thank!
Great to hear that! Thanks for your kind comment!
This Team makes automation faster and easier than i ever thought possible!
Thank you!
@@realpars Also waiting new amazing videos
Very usefull information, and very easy to understand!!!
Congrats
Great to hear that, Ervin! Thanks for sharing.
This channel is really helpful for me as a graduate electrical engineer. Would love to see more industrial videos. Thank you! Keep it up👍
That's an amazing compliment! Many thanks for sharing, and happy learning!
Always superb, good explanations, examples, explanation methods good. I expect more videos for PLC RELATED.. THANK YOU.
Great to hear that! Happy learning!
@@realpars thankfully
Great explanations and examples shown.
Thank you so much, Errnal!
You guys have the best explanations♥🙏
Thanks a million, Avinash!
Thank you so much, very informative ❤️❤️
Glad it was helpful!
Great presentation. Thank you
Thanks a lot, Lance!
É uma das melhores empresas.
very straight forward to the topic nice one
Great to hear!
I didn’t started watching yet but I subscribed . Learning to become commercial boiler mechanic
Happy learning!
Unbeschreiblich....vielen Dank🌹
Thank you, very useful ❤️
You are very welcome, Nihad!
I love your explanations but I will be happy to subscribe to your electrical instrumentations videos
Thank you very much! Glad to hear that
Thank you for your efforts!
Our pleasure!
I've used youtube since 2005, I've subscribed to hundreds of channels... but I only clicked the bell button on this one because the animation is great, the voice is great, the way it teaches is great, and most of all, it talks about devices that are actually relevant to the industry, including high-tech modern devices. Can't say the same about my university... learning about analogue meters. Jesus christ, what is this, 1950? Imagine having an interview and you get to teach the interviewer about the most modern up-to-date tech... that's a big deal. Managers don't want to employ guys that they have to teach... but it's great if the manager has someone who can teach HIM.
That is an amazing compliment! Thanks a lot for sharing this with us. Keep up the learning curve!
My one of the best CZcams educational channel.. I really learned a Lott about automation through your channel. Can you please explain how to do Programming in Softsorter
How to operate Softstarter?
Happy to hear that! Thanks for the topic suggestion, I will definitely go ahead and forward this to our creator team. Happy learning!
Go to the thrysistor chapter in koran
thanks for the upload ,
You are very welcome!
Such a great channel .
Thanks a lot, Bilel! Great to hear that.
Just installed one on my Central A/C's outside condenser to reduce inrush amps. Later I will get a whole house generator, this was the reason I installed it. My inrush amps went from 120A to 40A. It learned how much it needed to start and reduced over a few starts. 120A, 80A, 60A, 40A Something like that.
Your channel deserve more subscribers..
Thanks for your support!
Well done!!!
Thank you!
Thank you for helping
Our pleasure!
i continuously support you for your perfection in the automation field i suggest for you to give as a video on for Modbus tcp ip is connected between a step7 and numerical relay i followed most of your video in industrial communication but you did not mention this point good luck thank you in advance
Hi Moussa!
Thanks for your support and for sharing your topic suggestion with us. I will pass this on to our course developers!
Thanks for sharing and happy learning!
Thank yu reallpars for video
You are very welcome!
Best video.
Please make some videos on power system /substation automation.
Hi Elios,
Thanks for the topic suggestion, I will definitely go ahead and forward this to our creator team. Happy learning!
Thank you very much
Very nice video
You are welcome, Mohamed!
Like video. Use full. From Vietnam
Great to hear! Happy learning!
Great video
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Thank you!
youtube'taki en iyi sanayi kanalı.
Now I understood why my reactor agitator (current working place) start slowly then after 5sec it rotates fast. Thanks for uploading. Explained very well.
Happy to hear that! Thank you!
well explained thanks
You're very welcome - Samuel!
great video!!!
Thank you, Martins!
Excellent video
Thanks a million, Kenny!
Thanks !
Great video. Can you make a video about Pilz safety system, how to communicate with s7 and principle of it. Thank you guys so much.
Thanks for the topic suggestion, I will definitely go ahead and forward this to our creator team. Happy learning!
Great Video
Glad you enjoyed it!
Good job
Thank you, Eugene!
Great series ! Please make also a video about slip ring motors and their fluid starter.
Best channel ❤️
Thanks for your support, Zlatanic Saha!
Nice explanation of a soft starter. Can they also be used to power up step-up transformers? Where I live, i have 230V 3-Phase. My work shop main line is 16A 3-phase, 230V. Most of my machines run on 400V 3-phase, so i have a small transformer that is rated at 16A inlet and 10A outlet. Almost every time I switch on the thransformer circuit (through a contactor) the 16A circuit braker trips. This is due to high inrush current i believe. Some times i have to try 3-4 times or more before i can switch on the ciruit without tripping the breakers. Note, the circuit is unloaded when switched on. I never have problems when putting load on the circuit, such as motors etc.
Is this an application for a soft starter? Thanks.
The current on the secondary side of a step-up transformer will be less than that on the primary, since power (V x A) is conserved (minus a little efficiency loss). However, since the secondary (as well as the primary) are inductive loads, they behave somewhat like a motor would, with the possibility of a larger inrush current. I would use properly-sized time-delay fuses on the primary feed instead of the breakers you are currently using. This will likely fix your issue. You could try a soft-starter, but that will be expensive by comparison, and may not fix your issue.
Can you do an advanced video where you explain the function in more details with the correct formulars ? And you didn't mention another big problem when starting big (medium voltage) motors direct on line: The huge voltage drop which occurs due to the high starting current of 6-7 times nominal current. This is often not accepted by the power supplier company and therefore you have to reduce starting current with, for example, a stoft starter.
Please make the videos on different programming blocks in Siemens PLC
Thanks for your topic suggestion, I will go ahead and send this through to our creator team.
Success my bro... Your channel it's benefit ,good luck... Capacitor bank work? Please bro😁😁😊😊
Thanks a lot, Fikar! Great to receive your feedback!
Thanks.
Really well described. I have bought a 15kW Sawmill and I have bought a soft start with several different start modes. In my setting where I would like to start the motor without destroying the 25A fuse (3P 400V) I have 2 settings to choose from, Either:1. current limiting setting or 2.Voltage Ramp setting. But Im not sure which one to choose for my scenario, what do you think?
Hello Jonas Granlund,
Thank you for your question.
Unfortunately, I can’t answer your question, because I don’t know your application and your engineering setup. But I can suggest you look at your soft starters’ manual graphic charts to help you with your torque load and speed output at your load requirements. It should address the amps used for your settings. And make sure you have the wire feed sized correctly to handle the load.
Happy learning!
@@realpars Thank you so much for the response, when I look at the graphs and read the manual I get the feeling that the Current limiting mode is a little more advanced and reduce voltage when the Current start to overshoot the set-value. But I'm not sure how high I dare to set the current limit and the amount of second it needs to be delayed. This is what the manual say about this start mode: The current limiting starting mode is generally used in occasions with strict
requirements on starting current, especially when the power grid capacity is too small.
To limit the starting capacity, the current limiting multiple can be set according to
the requirements, which is generally between 2.5 and 3 times. If the setting is too
small, the normal starting will not be possible. When current limiting starting is
adopted, the starting time is related to the current limiting multiple.
nice video , keep going
Thank you, Eslam! We surely will - happy learning! :)
I build a simple soft starter circuit for use on some of my power tools. The big problem is that I must manually through a switch on the starter itself while the tool's switch is closed. Works great, but a hassle and dangerous. I wish someone came out with a small size retrofit addon kit for saws and other high surge current motors that don't NEED to have balls out instant starting. Be great for construction worksites running off a generator.
Makes me wonder if soft starters could be added before the electric socket, so whatever you plug into the circuit plug gets the soft start (one or more designated outlets for high current equipment)
@@troy3456789 Check out Raymond Innovations. They have a fully self contained soft start box you can plug into any machine that uses a brush type motor. I purchased the Model GS-10 a couple years ago and it works great! I use it for my Skil saw, chop saws, vacuum cleaners too. Does not work so well for motors that use a starting capacitor though. Not cheap @ 150.00.
are y'all gonna make a video on real pars on how to control a vfd with a PLC?
Thanks for your topic suggestion, I will pass it on to our creator team. Happy learning!
NICE VIDEO
Thanks a lot!
Thanks 🙏🙏🙏
You're very welcome!
I did an industrial practice and found a soft starter circuit on a cooling tower application
EXCELENTE VIDEO OJALA TODOS SUS VIDEOS TENGAN OPCION DE TRADUCCION
Thanks a lot, Jesus!
Hello Sir, for ur last example motor for conveyor, which one is good DOL or soft starter?
For conveyors, soft starters are recommended, especially if the conveyor needs to be started under load (with boxes, parts, or other pieces on the conveyor). Belt slippage with sudden starts with a DOL starter can cause the belts to wear faster, especially for larger systems.
Thanks
You are very welcome, Derin!
thx!!!!
Please make video on soft starter types.
Thanks for the topic suggestion! I will pass it on!
Do we need soft starters for hydraulic motors? Is there a a high inertia load in hydraulic motors compared to your large fan example in the video?
Torque is proportional to inertia The torque required for a hydraulic motor is dependent upon the fluid flow rate and pressure developed in the hydraulic lines (usually >1000psi). So, yes, hydraulic motors can have high torque requirements. For hydraulic systems, power clutches are used to regulate the starting pressures (hence, torque and inertia). These devices are not really soft-starters, but rather hydraulic "regulators" that act similarly to reduced voltage motor starters.
Nice video... It's educating. However I have a question; which capacity of Softstarter would be suitable for a particular Motor. Example, I have a 55kw electric motor, how many kw or amperage Softstarter would be suitable for that application
The best way to determine the proper Softstarter is to reference the literature of the manufacturer of your preferred vendor. 55kW (75hp @ 460VAC) requires a starter with a 110A capacity @ 460VAC. For example, see: new.siemens.com/global/en/products/automation/industrial-controls/sirius/sirius-hybrid/3rw-soft-starter.html or www.rockwellautomation.com/en-us/products/hardware/allen-bradley/motor-control/soft-starters--low-voltage/smc-50-solid-state.html.
Would we push so many of electrons to do the jobs that earth could do without even use of force? For example instead of using large motor to run the conveyor, we could use sensitive hydraulic balancing to tilt the conveyor and let the load and gravity play its way to destination or use gravity to fill the tank instead of pumping ?... The same concept for all one way road construction with 1 degree downward slope and reduce cost on transportation fuel or force on city road and streets design
Is it possible to use software Starter for slip ring induction motor,and can replace rheostat unit for higher starting torque?
Yes you can use a soft starter (not software starter) with a slip-ring induction motor. You can set up most soft starters to give a starting profile that meets your specific needs. Every motor is different, so if you are unsure of how to set up your specific system, consult your motor supplier for guidelines and limitations for starting circuits.
អរគុណ Thank
World top3 widely used Plc systems..
Siemens, Allen Bradley, Mitsubishi
Which one is best for 3 ton air conditioner?
@@ArcolaBridge I don't know. Maybe three them all possible because nowadays techniques are best upgraded.
Will the motor links have to be setup in delta with the Siemens Soft starter?
Yes. Delta gives you full voltage across each winding. The soft starter sort of acts as a Wye-Delta starter, giving a reduced voltage at startup.
I want my air conditioner to start quieter, would this help? I'm also wondering about whole house capacitor to prevent voltage drops and dimming lights?
Hi there,
Thanks for your comment!
This would make for a great topic suggestion for the future, I will happily pass this on to our course developers.
Thanks for sharing!
@@realpars you can get individual capacitors for individual appliances but I think it's an interesting question whether one could have a whole house capacitor to perform the job of avoiding voltage drop at air conditioners or other large appliances. I also think that appliances like air conditioners which are still 100% on or off are inefficient. Any large appliance that could potentially have any savings starting slower like an air conditioning compressor unit, HVAC fan, washing machine, oven, stove you name it, seems like everything should start slowly to save money. Or at least have an optional setting to do so like an eco mode.
you should upgrade your AC system with inverter compresor. It has variable speeds that depends on load. Lighter load, compressor runs slower and quieter
@@lordred7462 it is a new Goodman gsx13 scroll compressor, not bad... works very well but the start up is loud... I'd love to upgrade to a DC inverter style, wonder what a 3 ton unit would cost.
a video explaining how to control a soft starter using ethernet via TIA Portal please, thanks for all the effort xD
Thanks for your topic suggestion! I will pass it on to our creator team.
Hello ,
Please how do you make your animation ?
thank you for advance
Hi Fidele,
Thanks for your comment!
I am not sure about this as this is done by our Graphic and Animation department.
Muito bom o vídeo Se fosse legendado seria excelente para os surdos
really super
Thank you!
Suprised they don't build these things into most ac units,etc
Instant of star/delta circuit we can use soft starter?
The short answer is YES, since both limit the line voltage on start. The electronics inside of the soft starter represents an improvement over the star-delta (or wye-delta) starter arrangement, and soft starters accomplish the same benefits at a higher efficiency.
bueno los tutoriales
que programa utilizan para los graficos diseño
Muchas gracias, Angel!
To answer your question, I am not sure about this as this is done by our graphic and animation department.
Sorry about that!
As the terminal box is only at the fixed side then why you shown the input lines connected from different place for DOL and Soft starter as compared to star- delta..?
You are correct. Motors do have a terminal box on the motor to which all motor leads from the starter are connected. Showing different connections for DOL and Star-Delta in the video was for comparison and illustrative purposes only. The motor leads are connected to the same physical location on the drive in either configuration.
Have you got any PLC online course
We certainly do!
Our course library is specifically designed in a way where it provides all the tools needed for beginners to evolve into an advanced level through our hands-on courses. Feel free to browse through our course library to see all the different topics we are covering. bit.ly/30AVJaR
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Additionally, you will have access to our Technical Team - consisting of high ranking engineers with a lifetime of experience - who are here to help you out with any questions you might have along the way!
Hope this helps! If I can be of any further assistance, please let me know - I’m more than happy to help!
Existen cursos em português da Real parts ?
Hi Freddy,
Thanks for your comment! We currently only provide our course videos in English, you are always able to turn on the English subtitles as that might make it a bit easier for you.
Our apologies for any inconvenience!
Happy learning!
inrush... is not "voltage" BUT CURRENT!!
From 5 to 7 times the run current
The bigger the motor the more destructive is its INRUSH CURRENT at start up time.
VFD Soft-starters ramp up the PHASE FREQUENCY there by limiting the current required NOT the voltage.
👍🏻
A triac affects the voltage too.
Yes, the intent is to reduce the inrush current. But the control is via voltage. The triacs in the soft starter are triggered at a specified voltage of the incoming waveform to limit the voltage seen by the motor and thereby reduce the current consumed by the motor.
Low voltage=high current
High voltage=low current
Therefore if you intent to lower the current you need to adjust the voltage.
@@joeanne6258 No. We're not talking about a transformer where you're converting voltage and amperage while keeping wattage constant. We're talking about inrush current which is effectively determined by Ohm's law I=V/R. Since we can't do anything about the resistance, we decrease the available voltage via the triac.
I am from mechanical dept. Can anyone briefly tell what is triac? Is it also called ICBT?
Thanking you all.
At 3:10 I see the soft starter and, besides (parallel) a contactor. So, my question is : How these two components work together? It could be that when the motor starts only the soft starter works, then, when the frequency and voltage are adjusted (by the soft starter), the contactor is activated and the soft starter disconnected.
To me that's the explanation. But, another doubt : When we hit the stop button...Is the process the inverse of the starting? , I mean, both contactor and soft started are connected, the the contactor i disconnected and at the end only the soft started is stopping the motor?
I will appreciate your explanations.
You are likely correct on the use of the parallel contactor. It is also possible that this particular motor is used in two different modes, one requiring a soft-start and one that does not. Although not completely drawn correctly, Siemens does make a line of motor monitoring modules that is installed in parallel and is cabled to the main motor controller, but I would believe your suggestion is most likely correct.
@@realpars Thanks a million for your reply. I hadn't kept in mind the fact that a motor can operate in two modes: with or without a soft starter.
parallel contactor would represent an emergency bypass starter. When soft starter is nor working properly, the control will close the emergency bypass to allow motor operation.
@@mikeodell9688 A great explanation. You're right. Thank you so much!
Normally how many additional years will you add up to the life of the motor when using a soft starter compared with a full voltage starter?
Great question, but difficult to answer. Life of a motor depends on a host of factors, but using a properly sized, installed, and configured soft starter should extend the life of your motor by up to 25%. The normal life of a motor in years has too many variables to make a quantitative assessment of increased life in years. That all depends on the load, torque requirement at startup, motor design, and how the motor is run (frequent start/stop?, etc.).
@@realpars
Hope we can request manufacturers to conduct test
I dont think people understand the amount of current these large electric motors use. I saw an accident where the motor was physically isolated while fitters aligned the shaft. The apprentice was given the job of stripping and installing wires to the first junction box (safely isolated under permit). While aligning the shaft it is necessary to very slowly rotate the shaft 90 and then 180 degrees. Just a very slow quarter turn on the shaft was enough to generate quite shock and injure the apprentice. Heads did roll because anyone with a high voltage license should have known this. Hard instead of soft start at the same time as an alignment problem nearly bought down a five story structure with me on it and does do a lot of damage to a lot more than just the motor and system it is powering.
Thanks for sharing your thoughts and knowledge with us, Mick!
Mick This is a great comment and reference from experience. Once never had or seen this happen but you never quite ever know until it happens. As well I’ve been around 4160 Motors being aligned so never quite know until something unexpected happens.
Is it like a capacitor in a ceiling fan???
Can you explain in simple terms first and then in industrial level
INDHRA KIRANU N A it's like a dimmer on a light except changes the frequency going to the motor so it starts the motor slow and gradually increases the speed of the motor till full speed however vfds can do more than just ramp up the speed of the Motor they can control the speed of the motor as well as the rotation of the motor
INDHRA KIRANU N A Eaton videos has a 16 minute video on here called VFD 101 basics
That is one of the best explanations on YT
I have a 120vac water circulation pump I want to put a soft starter on.