KEB Technology

EtherNet/IP for packaging machinery



Full transcript

Hi, my name is Colin Zauner. I’m here with KEB America at the 2017 Pack Expo and today we are showing off our complete line of automation solutions.


Here we have our S6 servo drive. It is an EtherNet/IP slave so we can connect in here to the hub and transmit data to the HMI and also it can be controlled by any EtherNet/IP device.


We have our HMI here with an industrial IP66 bezel with over 60 million colors possible.


Here we have our DIN rail mounted IPC, the C6 Smart. It has a EtherCAT master as standard and also an EtherCAT backbone which you can attach all of the remote IO to. Another feature of the C6 Smart is that it can also connect to other EtherNet/IP devices that are in your machine. For example, here, the C6 Smart is handling all the intense motion. The other PLC up here is just sequencing what motion profiles to handle so it can do that with EtherNet/IP communication.


We have remote IO modules that act as an EtherNet/IP slave that help to transmit data back and forth between our devices as well. Here you can see we have our stepper drive which is handling all of the motion with the stepper motor here. The C6 Smart can handle real-time synchronous motion, it can handle camming, phasing, and gearing and all of that is easy to program with our COMBIVIS Studio suite.


COMBIVIS Studio comes with the ability to program all of your controls in any of the IEC 61131 programming languages and also we have a nice and easy wizards and graphical editors that make designing the cam profiles very easy and fast which reduces the amount of engineering time that takes to get a machine up and running.


Lastly here we have the C6 Router which allows you to remote connect to all of your devices anywhere in the world as long as it has an internet connection. We have a few different variants of our C6 Router. You can either connect to it with a standard Ethernet cable or you can have our wireless version which uses a SIM card for wireless cellular access. The C6 Router allows you to remotely connect to all of your devices with a VPN connection it can also be used to collect data from your devices that are in the field. you can push that data out to the cloud for collection and other data analytics.



For more information about our EtherNet/IP compatible devices software, contact a KEB sales engineer today.


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Servo or Induction Motor – Which is right for your application?

When looking to spec a motor for your application, do you select an induction motor or a servo motor?  What are the advantages and disadvantages of each?  These next few paragraphs will break down the benefits of both to see which motor technology is best suited for your application.


The two main factors to consider when choosing between servo motors and induction motors are of course performance and cost.  We can evaluate the performance of a motor by looking at its torque density, inertia, dynamic performance, and how easy it can be controlled by a VFD.  For your motor application, you will want to get the best performance at a the lowest possible cost.  Now let’s delve deeper into the performance of servo and induction motors.

Offset gearing with servo motor

A KEB servo motor with integral gearing. Servos tend to have a long narrow body.


Servo Motor Advantages

Permanent magnet motors, or servo motors, have been used in applications in the machine tool industry due to their easy motion control for both rotary and linear motion, as well as their high maximum speeds and short acceleration times.  The torque density is also a highlighting feature of the servo motor solution.  Servo motors can produce between 40 and 60% higher torque capacity than the equivalent-sized induction motor.  The motor compactness is particularly advantageous for machines where weight and footprint size are critical.



permanent magnets in servo

Permanent Magnets provide increased power density

The rotor size of the servo motor is also smaller in diameter than that of its equivalent induction motor counterpart, leading to smaller inertia.  This makes servo motors particularly attractive for dynamic motion control profiles.




Servo motors will provide full torque at zero speed.  This is not the case with a line started induction motor.  Applications that require full load at zero speed like a dynamometer or winder will benefit from this operating characteristic.



Advancements in VFD technology have allowed for the increase in usage of servo motors, because now manufacturers can offer VFDs with the capability to do complex current calculations and rotor pole identification in real time.  They can also offer solutions encoderless configurations, such as the KEB SCL solution.



Most servo motors are rated IP55 or IP65 as standard.  This is a higher IP rating than traditional ODP or TEFC motors that are going to be IP44 or IP54.

fanless servo motor

Servos like this one do not typically have a fan. One less point of ingress means the IP rating is typically higher.


Servo Motor Disadvantages

As far as costs go, servo motors have traditionally been more expensive due to the permanent magnet material cost.  But the cost gap between servo and induction motors has been shrinking for years.  It used to be that a servo system was mabye twice the cost of an induction motor system.  That difference has now shrunk to maybe 10-40%.


In some applications the servo motor advantages become disadvantages.  Machines like a crusher might benefit from a higher inertia motor that can ride through torque impulses.  Also, applications that do not require speed or position feedback can be more easily solved with a line start induction motor.  There are some line fed PM servos out there but a majority will require the use of a servo drive or amplifier.


Servos can be optionally equipped with brakes but they are mainly for holding or e-stops.  Having said that the size of the brakes offered with servos might be limited.  Also, brake options like hand releases or microswitches might not be readily available.  Another important point is that some Servo motors use Permanent Magnet brakes.  While PM brakes are power-off, they are not considered “failsafe” and might not be the best option for safety-related applications.  It is possible to equip a servo with a spring-set brake but its a point worth considering.



Induction Motor Advantages

Three phase squirrel cage induction motors have historically represented the premium low-cost choice for simple, single speed applications, such as material handling conveyors, rotary turntables, fans and other simple systems.  Although the cost difference of a servo motor in comparison to a similarly sized induction motor is not nearly what it used to be 10-20 years ago, induction motors still have their place in certain applications, and a servo motor is not always the right replacement for an induction motor if you can justify the added cost.



For example, if you need to maintain a constant speed at a large load, say for applications greater than 30 or 40HP, the induction motor would likely be the better choice.  This is due to the high costs of producing the large number of permanent magnets needed for such a large motor, coupled with the fact that quick accelerations, high dynamic speeds, and accurate positioning aren’t requirements for the application.


Also, although vector driven induction motors do require feedback controls, or encoders, to compete in performance to servo motor control, advancements in drive technology now allow us to run the motor in closed loop vector mode without the need of an encoder.  KEB calls this its ASCL drive technology.

induction vector motor encoder

Vector motor control still offers positioning and precise speed control capabilities


Induction Motor Disadvantages

In general, Induction motors will be larger and have more inertia than Servo motors.  So they will not be the best option for highly dynamic applications although they can do positioning when equipped with the correct feedback device.


Induction motors will be slightly less efficient than servo motors, particularly at smaller sizes.  However, with recent legislation, the required efficiency levels have been increased and the gap between Servos and Induction motors has been reduced.



In Conclusion


Both induction motor systems and servo systems can be the right fit for your application depending on your performance and pricing needs.  Induction motors can offer lower cost, reliable, and rugged solutions for single-axis applications with simple motion profiles.  Servo motors can offer high dynamic performance and torque density, but at a premium cost.


Here at KEB, we are glad that we can offer both induction motor solutions ranging from .25 to 50HP and servo motor solutions ranging from .25 to 20HP.  We can also offer both the induction and servo solution with integral gearing.


We have helical inline, right angle helical bevel, right angle helical worm, parallel shaft, and planetary gearing available.  If you don’t know what solution is best for your application, we are more than happy to help you spec the correct motor.


Please contact a KEB representative near you if you have any application questions or need more information.


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Unintended Car Movements and Elevator Drives

Elevator safety is a top concern for all involved with the industry. In order to ensure the safety of passengers and maintenance personnel, most countries have adopted some sort of elevator code that specifies a large number of safety functions that an elevator must have. In Europe, the current standard that is being used for elevators is the code EN 81-20:2014 for passenger elevators. This safety code covers the entire system and what types of safety devices are required. One section of this code – 5.6.7 specifically – pertains to unintended car movement (UCM) of the elevator car after a normal run.  This post describes how a KEB Elevator drive can be used to meet the intent of the UCM code.




When an elevator has finished its normal run and come to a stop at the floor desired, you want to ensure that it doesn’t move while passengers are getting on or off. You also want to make sure that the brakes you are using to hold the car in place are functioning properly so that if the car does move unintentionally, it can be stopped before it moves too far and someone is hurt. It is possible to use a KEB drive to monitor the movement of the car as well as make sure the brakes are working properly.


KEB brake for elevator motor

Elevators can use a variety of different brake types including drum brakes


The elevator code in Europe that was mentioned in the introduction specifies that two separate brakes are required to hold the car in place in the event of unintended motion. Most elevators have a main brake and an emergency brake. This provides redundancy in case one of the brakes fails so that in the unlikely case that there is an unintended movement of the car and one brake stops working, the car will still stop and the passengers will be safe.

Unintended Car Movements and Elevator Drives

Dual circuit elevator brakes provide redundancy


Brake Monitoring

Part of making sure that the elevator is safe is monitoring the brakes to make sure that they are opening and closing when appropriate. The KEB F5 drive can monitor both the main machine brake and the emergency brake when two of the inputs are configured for brake monitoring. The brake monitoring function on the drive uses an input that comes from the brake to verify that the brake is in the correct position. If the drive detects a failure based on the input, then it will trigger a fault and prevent further operation of the elevator until the failure is fixed. This helps to ensure that the elevator will not be used by anyone if a brake has failed. Using the F5 drive, you can set the fault response such that the elevator cannot move until a qualified maintenance person has physically reset the fault and fixed the condition that caused the fault.


Unintended Car Movements and Elevator Drives - brake microswitch

A brake microswitch provides feedback that the brake is engaged


Position Detection

Unfortunately, you can’t schedule unintended movement because it is unintentional. What elevator safety codes specify is to try to mitigate any potential issues that might be caused by unintended movement. Imagine an elevator that has come to a floor and passengers are getting on and off. If the car were to move suddenly, it could cause major problems if it were not stopped in short order. The KEB F5 drive can monitor the position of the elevator, and if it detects movement when the car should be stopped, it will trigger a fault that causes the brakes to drop and holds the elevator in place. The drive uses the motor encoder to determine if the motor has turned while it should be stopped. If the motor moves a certain distance, then the drive will trigger a fault and prevent any further operation of the elevator. As with the brake monitoring, you can adjust the response to this fault so that the elevator cannot be run until a qualified maintenance person has reset the fault and made sure that the conditions are safe. This ensures that if the elevator does move when it shouldn’t, it will be stopped after a short distance and further operation will be prevented until the situation has been fixed.


Unintended Car Movements and Elevator Drives - dual channel VFD encoder card

UCM can be detected in the drive by monitoring the encoder counts


When you step into an elevator, there is an expectation that the elevator will get you to your destination safely. KEB is committed to helping that happen, striving to offer a high-quality elevator drive with functions that can improve the quality and safety of the elevator. The brake monitoring and unintended movement functions are two options that KEB offers as a part of the elevator drive to help ensure safety throughout the process of an elevator ride.


These safety functions are designed to meet the intent of EN 81-20:2014 section 5.6.7 but have not been certified by a third-party and functionality must be tested according to documented procedures to ensure the safety of the elevator. Elevator manufacturers will want to ensure that the elevator matches the code for the jurisdiction of the elevator.


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7 tips for Long Encoder Cable VFD applications

There are a number of issues that arise when a VFD and motor are mounted far apart.  A previous post went over voltage spikes due to dV/dt of the drive’s PWM switching.  The answer to that problem was a dV/dt choke or sinewave filter.


For closed loop applications, another problem that can arise when a drive and motor are located far apart has to do with the encoder signals.  Specifically, the voltage drop experienced on encoder signals.


This post will outline the problems of long feedback cable runs and how to address them.


Voltage Drop of Encoder Signals

The encoder cable is basically a transmission line carrying the encoder signal from the encoder device to the encoder card on the VFD.  The encoder cable has some impedance which is a characteristic of the cable design.


The cable resistance should be listed on the manufacturer’s cable data sheet.  The resistance is usually listed as some value per length – (e.g. Ohms/meter or Ohms/ft.).  The longer the cable the more resistance it will have.  And the more cable resistance, the more voltage drop the signal will have.



encoder cable resistance

Standard KEB encoder cable resistance is called out in our manual



Let’s look at an example.  Assume a worst-case scenario of a 200mA current draw.  Using the data above for a 75-meter application, a TTL signal will lose 1.05V due to the voltage drop.


Encoder cable voltage loss

A long encoder cable run will cause the signal voltage level to drop


The most commonly used incremental encoders are the TTL type and have a target “on” voltage level of 5V.  However, the drive’s encoder card will have an acceptable range on the voltage level that the drive or encoder input will accept.  For example, KEB’s encoder cards recommend a minimum of 4.75V for the “High” TTL signal.


If there is too much voltage drop the TTL signals, you will get erratic operation and nuisance trips – the worst kind and a pain to troubleshoot.  A common error is that the A or B channel compliment does not match the respective channel.  With KEB Combivert F5 inverters, this will result in the E.EnC1 fault.


So if you are experiencing random encoder faults and suspect too much voltage drop, here are 7 things you can do to address the issue.


1. Use a Shorter cable

This one is simple but is worth mentioning because it might be the easiest to implement – if possible, use a shorter feedback cable.  I’ve seen many applications where they use a “standard” cable or something they have on the shelf.  The result is they use a much longer encoder cable than they really need.


An excessively long feedback cable can also couple unwanted noise and introduce other issues.  So, use the shortest possible encoder cable that is practical for the application.



2. If powered from the VFD – Increase the supply voltage


Some encoders receive power from the drives control/encoder card.  The Push-Pull type TTL encoders will output a signal amplitude that is proportional to its supply voltage (i.e. there is no regulated supply onboard).  With these types of encoders, there are effectively two conductor voltage drops – the supply, and the return.


encoder card supply voltage

The voltage drop will be highest when the encoder is powered from the VFDs encoder card.


KEB’s F5 drive uses a fixed 5.2V supply to power the encoder.  The idea is that the extra .2V compensates for some voltage drop.  Some other encoder cards have means to increase the supply voltage.


If possible, you can adjust the encoder card supply voltage up.  Just be sure to use a voltmeter to measure the supply voltage and check the encoder specs to make sure a higher voltage is permitted.



3. Apply power at the encoder


Another option (if supported by the encoder) is to apply the supply power directly to the encoder.  Since the supply is directly applied to the encoder, this allows only one voltage drop on the feedback signals – effectively cutting the total voltage drop in half compared to the initial example.


TTL encoder local supply

Applying power at the encoder can help reduce the voltage drop


Check your encoder datasheet to see how the encoder can be powered.  Some encoders can only be powered from the drive’s encoder card.  However, other encoders are designed to allow a direct power source.  Some might even allow a higher input voltage like 24V but then regulate the output voltage accordingly (e.g. 5V).


So do check the encoder data sheet and see what the input power options are.


4. Consider using HTL logic

A “High” or “On” level for HTL logic is defined between 15V and 30V, with a target of 24V.  KEB F5 HTL encoder cards will have a regulated 24V supply that can be used to power the encoder.  Because the HTL signal is higher, it can support more of a voltage drop before hitting the lower “On” threshold.


HTL provides much more room for voltage drops – 9V from the regulated supply to the lower threshold (24V-15V = 9V).  Compare that with TTL’s range of only 3V from supply to lower “High” threshold (5V-2V).


HTL encoder waveform

HTL logic provides a higher voltage compared to TTL


Just be sure that the drive’s encoder card supports an HTL input or the card could be damaged.



5. Use an encoder cable with lower resistance

KEB offers special encoder cables for long distance runs.  The cables use larger conductors so they have less resistance.  Less Ohms/meter will result in less voltage drops on the feedback signal.


TTL long encoder cable

KEB offers feedback cables for long encoder runs


6. Use a signal repeater

Another option is to use a signal repeater.  Signal repeaters were commonly used before real-time fieldbuses like EtherCAT were available.  They function by splitting, amplifying and conditioning the encoder signal.


KEB offers a signal repeater like this (00F4072-2008) that can be used for long run and multi-follower applications.



7. Use Fieldbus I/O – Like KEB’s Counter module

Another option is to use a fieldbus encoder module to transfer the data.


KEB’s encoder module allows the input of up to 2 TTL encoder signals.  The encoder signal is wired to the module where it is converted and transferred via the EtherCAT bus.


ethercat encoder module

It’s possible to transfer the encoder feedback via the EtherCAT bus


One big advantage with this solution is the low cost of a CAT5/6 cable.  The cabling cost will be much less than a long encoder cable.  The second advantage is that the position is now on the bus and available for use by the control without any other handling.


One consideration with this implementation is the input delay.  The listed value for the input delay on the KEB module is 1ms.  This will be suitable for most motion applications but you’ll want to verify it with your individual application.



I’d be interested to hear of other solutions or problems you’ve encountered.  Leave your comments below.


Have questions? – Contact a KEB Application Engineer today.



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dV/dt Chokes for long VFD runs


VFD switching frequency

VFD switching frequency refers to the rate at which the DC bus voltage is switched on and off during the pulse width modulation (PWM) process.  The switching on and off of the DC voltage is done by Insulated Gate Bipolar Transistors (IGBTs).   The PWM process utilizes the switching of the IGBT’s to create the variable voltage and variable frequency output from the VFD for control of AC induction, permanent magnet synchronous or DC motors.  The switching frequency, sometimes called the “carrier frequency”, is defined using the unit of hertz (Hz) and is typically in the kHz (Hz*1000) range, typically ranging from 4 to 16khz, or 4000 to 16000 switches on/off per second.


To determine what switching frequency would work best for your application, it is beneficial to look at the advantages and disadvantages as the switching frequency is increased.


Switching frequency – Effect on current distortion

The harmonic content in the current waveform generated by the PWM process is reduced as the switching frequency increases.   The ‘cleaner’ waveform results in higher efficiency by reducing the current ripple, which results in lower motor losses.   This benefit of a higher switching frequency is more pronounced as the output frequency to the motor increases.


The effects of using different switching frequencies can be seen in the application below.  A surface mount permanent magnet (SMPM) motor is run by a KEB high speed VFD.  The operating point of the system is 50kW @ 10000rpm (333hz).  Figure 1 shows the current waveform (green) and the PWM output of the VFD (red) at a 4khz switching frequency.   In this application, the required current to reach the operating point is 178amps.


The formula for the total harmonic current distortion (THD(I)) is:

Current distortion formula for VFD


I1 = r.m.s. current at the fundamental frequency

In = r.m.s current of nth harmonic

n(max) is the number of the highest measurable or significant harmonic.  In this case, the highest harmonic used was n = 50.



For this application, running at 50kW @ 10000rpm, using a 4khz switching frequency, the THD(I) = 12.69%.

THiD at 16kHz switching frequency - higher output

50kW @ 10000rpm, using a 4khz switching frequency, the THD(I) = 12.69%



Running the system at the same operation point (50kW at 10000rpm) and increasing the switching frequency to 8khz gives the current waveform at the motor shown in figure 2 and the resulting THD(I) = 6.27%.

VFD switching frequency - THiD at 8kHz switching frequency - higher output

50kW @ 10000rpm, using a 8khz switching frequency, the THD(I) = 6.27%


The reduced current distortion translates into lower rotor heating of the motor and a higher motor efficiency.  The reduced rotor heating is of great concern when motors utilize bearing technology that requires very small clearances (air foil or magnetic).  Excess rotor heating can cause the rotor to expand or elongate, which could result in the rotor impacting the bearing surface.


Switching Frequency – Effect on high frequency outputs

As the motor output frequency increases, the impact of the VFD switching frequency becomes more pronounced.  Using the same motor as above, the operating point was increased to 100kW at 20000rpm (666hz).  Again, the required output current from the VFD to reach this operation point was 178amps.


At 4khz switching frequency (figure 3), THD(I) = 17.27%.

VFD switching frequency - THiD at 4kHz switching frequency - higher output

50kW @ 20000rpm, using a 4khz switching frequency, the THD(I) = 17.27%


At 8khz switching frequency (figure 4), THD(I) = 8.47%.

VFD switching frequency - THiD at 8kHz switching frequency - higher output

50kW @ 20000rpm, using a 8khz switching frequency, the THD(I) = 8.47%


At 16khz switching frequency (figure 5), THD(I) = 4.05%.

VFD switching frequency - THiD at 16kHz switching frequency - higher output

50kW @ 20000rpm, using a 16khz switching frequency, the THD(I) = 4.05%


The higher switching frequency decreases the audible noise that can be heard from the motor.  The audible noise from the motor is a result of the stator laminations vibrating at the carrier frequency rate.  As the carrier frequency is increased, the pitch of the noise from the stator laminations is increased moving the levels farther out of the normal hearing range of humans.  Motor noise levels may be of concern based on the application requirements (elevator motors, theater equipment, etc.).  In these cases, a VFD with a higher carrier frequency may be an option.


As the switching frequency increases, motor heating due to higher harmonic content in the current waveform decreases.  At the same time, the heat generated internally in the VFD due to the IGBT switching is increased.  Each switching action of the IGBT produces a relatively fixed amount of heat loss.  So as switching frequency increases so does the overall heat loss of the VFD.  The heatsink of the VFD must be designed to provide sufficient cooling of the VFD to operate during the maximum rated ambient conditions.  KEB drives are rated based on a specific switching frequency.  It may be possible for a specific drive to operate at a higher switching frequency than rated, but the output may have to be reduced in order to keep the drive from overheating.  If the system requires a higher switching frequency, then the heatsink may need to be increased in size, have increased air flow or liquid cooled.  All of these options are available on KEB drives.


Because of the higher heat loss due to the higher switching frequency, and the fact that the heatsink may need to be larger (if air cooled), this results in a larger physical size VFD and consequently higher initial component costs.


KEB has an option for liquid cooling of the VFD for situations where space may be an issue.  While this does potentially reduce the physical size of the VFD housing, it does introduce the requirement for access to a cooling fluid.


The VFD ratings are based on maximum ambient conditions.  In most cases, the VFD is mounted inside an electrical enclosure.  There for the maximum ambient temperature around the VFD becomes the temperature inside the enclosure.  With a higher heat loss from the VFD due to the higher switching frequency, this introduces more heat loss into the enclosure.  The higher enclosure heat load may require additional cooling (fans, air conditioner) to be added to the enclosure itself, depending on the application requirements.


The VFD switching frequency used for a specific application depends heavily on the application requirements and components in the system.   Motor design, noise levels, required system efficiency, cooling requirements and component costs all need to be considered when determining the optimal VFD switching frequency for the application.


KEB VFD’s can operate at switching frequencies up to 16khz.  KEB has a strong background in applications requiring high switching frequencies.  Because of our extensive application experience in these types of applications, KEB drives have been developed to deal with the inherent challenges that come with the higher switching frequencies.  Whether your application requires a high switching frequency or not, KEB has the options and expertise to help you meet your application requirements.


If you are unsure what switching frequency is the best for your application, contact a KEB Applications Engineer today.

Artificial intelligence and the future industrial job field

The notion that developing efficiency in the way we work will destroy the future job market is not new. Articles and editorials currently making the rounds show a range of reactions to how robots and artificial intelligence will affect the workforce.


The hashtag #RobotsDontKillJobs was rising on LinkedIn recently, alongside the publication of this article by Germany has way more industrial robots than the US, but they haven’t caused job losses. With Germany being a leader in manufacturing, it’s no wonder people are looking to their experiences to learn more about how robots are integrating into the landscape. And the results show that over the last 20 years they’ve integrated extremely well, increasing productivity and profitability. During that same time frame Germany saw little to no change in employment statistics.


This type of automation – what we like to call “cobots” – where robots work with people in the highly-skilled areas of the manufacturing floor is where KEB products shine. The C6 line of automation tools was created to seamlessly fit into an existing installation so the humans and robots can keep the conversation flowing freely. Products like the C6 Industrial VPN Router for connecting to the production floor, our range of IPCs for automation and maintenance and HMI for visualization and control. Connect everything with KEB’s COMBIVIS software. When good communication happens, work is done faster and with more efficiency.


Artificial intelligence - automation products for better efficiency

click to enlarge


There is, of course, the flip side of the story. On that same trending hashtag, I came across this article from The Reports Are In: AI and Robots Will Significantly Threaten Jobs in 5 Years. Wait… I thought our jobs were safe from the robots? If we take a look at the kind of work that can be automated, it’s mainly things that can be done by less-skilled hands. Entry-level work is starting to disappear from job postings as these tasks are falling to robots. Workers in positions that require a higher amount of skill and experience seem to be safe from the robot takeover, and in fact are starting to see more job security according to the article, but younger workers aren’t able to get in on the ground level of manufacturing any more, and those with years of experience in the less-skilled tasks have seen a big drop in job security.


artificial intelligence - designing robot componentsIf the future of the engineering job market lies in more skilled jobs that work alongside robots, those of us currently in the field should work to ensure tomorrow’s engineers are ready for the task. Encouraging STEM development in schools and in extracurricular opportunities for underrepresented groups in the engineering field will be an important part of the future industrial job field. Here at KEB we frequently work with universities in the Twin Cities area and beyond offering internship opportunities. We’re able to provide practical experience to students wanting to put their engineering theories to work on the newest automation tasks.


When it comes to designing the tools for modern industrial settings KEB prefers to build systems unique to each problem to be solved, rather than selling individual products. That’s why we’ve engineered a wide variety of options into the brakes, drives, and motors available. In this way we can better assist our customers in designing an automated workflow even if they already have robots at work. KEB robotic clutches and brakes are perfect for applications that require highly precise movements.


artificial intelligence - programming AIRobots have been part of the manufacturing world since the Industrial Revolution, yet with each new technical development the worries resurface. In the coming years, a new fear will likely creep in – the proliferation of machines with the ability to learn. Not only will we rely on robots to do simple tasks, but as time goes on they will get better at anticipating issues and adjusting accordingly without human direction. Heavy hitters like Elon Musk, Stephen Hawking, and John Giannandrea of Google are raising their concerns about possible bias in artificial intelligence algorithms. These types of algorithms typically aren’t a part of industrial manufacturing, but the precedent is being set. Computers are frequently being taught to learn by people who do not have expertise in that particular field and those using the computers are not able to view or analyze the proprietary algorithms. If this trend continues the lack of transparency and niche knowledge in artificial intelligence could create a future job field that’s closed off to many potential entry-level engineers.


Did the digital camera kill Kodachrome film, and in turn has the smartphone caused digital cameras to fall out of favor? Is it Amazon’s fault that Sears is closing stores all over the country? Are millennials killing … well, everything?  Probably. Will robots take over someone’s job? Of course they will. The job market of our parents is not the same as the one we came into, and when our children or grandchildren look for their first jobs it will certainly be changed again. And in the end, if Steve Wozniak isn’t worried about robots then we’ll probably be OK.

Electric Motor Brakes

Electric motor brakes are used to decelerate or hold motor loads when the power is cut intentionally or accidentally.  KEB has been supplying motor brakes since our founding – this gives us more than 45 years of experience.


Beyond our core brake technology, KEB is able to offer custom designs which help motor manufacturers during assembly and meet the application requirements.  This post gives an overview of KEB’s motor brake technology and some of the value-add we provide motor OEMs.



DC Spring-Set Brakes

KEB specializes in the design and manufacture of DC spring-set brakesCompared to AC Brakes, DC brakes offer a number of advantages including: simple operation with no linkages, less adjustments needed, less ongoing maintenance.


When we replace AC brakes, it is typically in those really demanding braking applications where there is a high cycling rate.  The solenoid and linkages in the AC types do not stand the abuse and wear or fail prematurely.


failsafe springset motor brakes

See how KEB Spring-set Motor Brakes operate



KEB can offer brake coils wound for any voltage including battery power machines using 12VDC and 24VDC.  Using a KEB bridge rectifier, AC power is easily converted to DC power for the brake.



Motor Brakes to handle Tough Applications

KEB brakes are designed for demanding industrial applications.  Our friction linings and coil voltage tolerance all have internal safety factors built-in.  This becomes important for demanding and safety-critical applications.  As standard, KEB’s spring-set brakes are CSA listed and UL can also be designed for.


electromagnet design software

The use of tools like magnetic modeling software allows KEB to offer best-in-class brake technology


KEB can offer special brake solutions as the application requires.  We can offer IP65 brakes for washdown and outdoor installations.  We can offer high energy brakes for applications where the brake is required to stop very large loads repetitively.


washdown brake

This Type 28 Spring-set Brake is suitable for NEMA 4X applications


We offer silent brakes for theatre hoists and elevator motors that are noise sensitive. We offer special brakes for applications in moist and humid environments.


If you have a demanding application, chances are we already designed a solution for the applications.



Mounting Options

Because we have internal design capabilities here in Minneapolis, we can customize our brakes to meet the requirements of the motor design.


Most commonly, KEB supplies the brake assembly and our customer mounts it to the outside of a prepared end bell or mounting flange.  Optionally, KEB can provide the mounting flange or NEMA C-Face adapter plate.

cface brake

This brake is prepared for NEMA C-face mounting and has a protection cover


We have also done designs where the brake is mounted inside the motor housing (e.g. servo motor brake).  The advantage is that the customer is able to get an IP65 designed brake.  However, this should be used for holding brake applications only as the brake is not easily serviceable.


brake in servo motor

This brake is designed to mount inside a servo motor


Besides the mounting flange, we can also provide other customized options.  We can provide extra long leadwires if needed, or special connectors.  Additionally, we can provide special hubs or rotors that are located off motor shaft features (step or snap ring).


Double C-Face Brakes

One option customers like for both new and retrofit installations is KEB’s Type 17 Double C-Face Brake.  The Double C-Face Brake is a power-off DC spring-set brake.  The deisgn includes an integral NEMA input flange and output flange and shaft.


nema cface brake

See how KEB’s C-Face Brake operates


This brake is typically mounted in between a NEMA C-Face motor and a gearbox.  Some customers prefer this brake as it is modular and the gearbox, brake, and motor can all be serviced or replaced individually.


The Type 17 brake is offered with a variety of different magnet voltages and includes a conduit box for making the wiring connection.  As standard, this product is designed with NEMA 4 protection and includes a manual hand release.


The product can be paired with 56C through 286TC NEMA motors.


cface brake

KEB offers double CFace brakes through 110Ft.Lbs.



Electric motors are used in a wide variety of applications, with most of them requiring a brake. With KEB’s history, experience, and reputation of supplying the highest quality of brakes we are confident that we can find the brake for your application.


Even if you have a custom application requiring a different brake style (permanent magnet or power on brake)  –  feel free to contact us and one of our Engineers will take a look and specify the correct brake for your application.


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