Industrial Electronics Repair

Difference Between VFD, Servo Drive Repair

Posted August 31, 2016 by Pepper Hastings

Categories: Blog, Industrial Electronics Repair

Tags: ,

Servo drive repair differs from VFD repairs in several ways, including being a bit more difficult to troubleshoot. Also, servo drive repair usually requires that the servo be connected back to its intended system to ensure it's repaired correctly (something that's extremely difficult to replicate in repair shop conditions).

A VFD (variable frequency drive) is generally used to control a squirrel cage type motor, where both stator and rotor are of a wound type to create the magnetic flux.

Servo drives are used to control permanent magnet motors. They are called permanent magnet motors because they use rare earth magnets in the rotor to create a much higher magnetic flux for their given size. This enables the motor to create more torque in a much smaller motor size. This means the motor has a lower inertia to accelerate and decelerate much more dynamically than that of the asynchronous squirrel cage type motor.

servo drive repair

Servo drive repair can be more difficult to troubleshoot in a shop setting than a VFD.

On the controller side, the servo controller can calculate a complex path and maintain the position along that path with varying loads and speeds. Many servo controllers are multi-axis or can be daisy chained to make multi-axis moves to follow complex paths.

Because of these differences, a Servo drive repair is much different than troubleshooting a standard VFD.  When isolating the issue with a servo drive, you must consider the entire system, drive, cabling and motor.  It's difficult to troubleshoot a servo without all three of the main components present.  And since servo drives are designed to run a specific magnetic flux motor, it is close to impossible to test them outside their designed system.

Check These Prior to Servo Drive Repair

We've compiled a list of the top simple issues that should be checked before sending in your unit for servo motor repair. Please note this is not meant to be an insult: I very often spend time trouble shooting over the phone to eliminate simple errors or problems. Double check everything before electing to send in a motor for repair, otherwise time has been lost in both the shipping and evaluation.

  1. Occam's Razor: The simplest explanation is most often correct. Make sure everything is plugged in. Try turning your drive and controller off, and reboot.
  2. Check All Servo Motor Cables. Look for items such as Broken Wiring, Loose Connections, Dirty and Corroded Connectors - bad connections can interfere with the power and signals that are vital to proper servo operation.
  3. Check Overall Cable Conditions
  4. Check Grounds and Shields. Just because a cable is in good shape doesn't mean it is properly grounded. Keep in mind that grounds and shields are important for protecting signal wires from harmful noise that can disrupt feedback communication. Motor power grounds are important because they facilitate the tripping of over current protection devices. If a motor has an inconsistent ground that is not continuous with a drive ground the power cable can throw an unmanageable amount of noise onto a properly shielded feedback cable.
MarcCropwBackground

Phelps

If all this checks out, then you probably have a servo drive issue that requires shop servo motor repair.  Use a repair shop that can help you isolate the problem, but as mentioned above understand it could require some additional testing at your sight AFTER it's worked on at the shop. If your repair facility also has industrial field service technicians, so much the better. They can can help you with onsite troubleshooting of servo systems.

Marc Phelps is manager of the Innovative-IDM repair facility in Houston. You can contact him at marc.phelps@iidm.com

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Baton Rouge Flooded Control Panels

Posted August 30, 2016 by Pepper Hastings

Categories: Blog, Industrial Electronics Repair, Industrial Maintenance

Tags: ,

Fairchild uses a pressure sprayer on an electrical panel. No, it's not plugged in.

Fairchild uses a pressure sprayer on an electrical panel. No, it's not plugged in.

Our customers and employees in Baton Rouge continue to endure dire conditions from the staggering flooding in that area and throughout southern Louisiana. One of our customers, a printing plant, sustained horrible damage. Everything flooded. Office turned upside down. Every control panel went under water.

On the scene, IIDM field service technician from our Baton Rouge office Joey Fairchild surmised the situation: "We are attempting to save all the wiring, term strips and relay sockets. The plan is to replace every component. I’m working on that now. I’ll let you know how it goes in a week or so. Power stayed on. However we will need to clean distribution gear at some point."

Fairchild said the plan is this:

  • Pressure wash the mud and oil coating with a degreaser. It was all wet anyway.
  • Dry with fans 1-2 weeks while parts are ordered and delivered.
  • Send flooded motors out for rebuild.
  • Send high HP drives in to IIDM repair facility for rebuild.
  • Megger test all wiring, with components removed, to find shorts/moisture.

The photos and video tells the story better than words.

Baton Rouge Flooded Control Panel from Innovative-IDM on Vimeo.

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How Are Your Capacitors Doing?

Posted August 13, 2016 by Pepper Hastings

Categories: Blog, Industrial Electronics Repair

Tags: ,

Industrial electronics use Electrolytic Capacitors on control and power boards, power supplies and elsewhere inside the component. From our experience, unfortunately, capacitors are the most high-fail component in electronic devices. The great news is, a reputable repair facility can bring your component back to life.

capacitor

Capacitors are some of the most fail-happy components in industrial electronics. Temperature extremes are a key reason.

VFDs use Electrolytic Capacitors in the DC Bus section. Capacitors store and release energy as needed within a circuit. Larger capacitors generally have higher current load-handling ability and greater charge storage capacity. These properties are well-suited for large VFDs because some A/C motors need a pulse of energy 300 to 500 percent of normal to get them going. A Bus capacitor in a VFD is used for this application. Capacitors are the most high-fail component in electronic devices.

Why Capacitors Go Bad

The caps can go bad due to age or temperature transients. Typically, the function a capacitor is to act as a power supply filter.  It’s comprised of two strips of aluminum foil (called plates) separated by a paper insulator.  The foil and paper are rolled into a cylinder and immersed in an electrolyte solution consisting of an ethyl glycol fluid. This electrolytic moist separator inside can and will dry out if the unit gets too hot, causing it to develop an internal short circuit. The capacitor can fail if its temperature routinely goes above 150 degrees Fahrenheit or below 32.

Also when large amounts of current flow into the capacitor, it causes the electrolyte solution to boil and turn into a gas. Once turned into a gas, pressure builds rapidly until, hopefully, the safety vent plug releases pressure. (Thus, the term “puffy caps”.) This rupture can be dramatic and destructive. Not only is the boiling liquid and gas hot, it is also corrosive and will damage any components covered by the solution. Under controlled laboratory conditions, measurements have been taken during a violent, large capacitor rupture.  The equivalent explosive force of half a hand grenade has been measured. Many of the violent failures have been captured by mad scientist types on video.

The dielectric oxide-insulating layer is created during manufacture.  However, it will deteriorate in the absence of a sufficient rejuvenating voltage, and eventually the capacitor will fail if voltage is not applied.  Maintaining the integrity of the dielectric requires the steady application of power.  When voltage is applied, the oxide layer is rebuilt.  The oxide layer thickness is the crucial factor to determine the voltage rating of the capacitor.  Otherwise, the oxide layer will break down under voltage and cause a spectacular failure.

By applying voltage to the capacitor on a regular basis, the oxide layer is “reformed”, and the integrity of the insulating characteristic is ensured.  In our experience, the maximum time between power ups should be no longer than one year, provided the equipment is kept in a dry location at roughly 70 degrees F. Large temperature swings require less time between power ups.

In conclusion, look through your shelves to see if you have any electronic equipment that has not been powered up in the last 12 months or what equipment is operating in extreme temperature swings. Do you have equipment like this? If the answer is yes, you should seriously consider sending it to a trusted repair facility to be checked out in a controlled environment.

MarcCropwBackground

Phelps

Many repair facilities, like Innovative-IDM repairs offer a free evaluation on all repairs, and can determine if it time to “refresh your caps”.  As a part of any repair we do, we replace all capacitors more than 5 years old, or any showing signs of degradation. Don’t let a faulty cap result in downtime at your facility.

When he's not collecting on bets, Marc Phelps is manager of the Innovative-IDM repair facility in Houston. You can contact him at marc.phelps@iidm.com

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Touchscreen Repair: When to Replace, When to Repair?

Posted February 24, 2016 by Pepper Hastings

Categories: Industrial Electronics Repair

When you talk about touchscreen repair, it’s more than just another piece of equipment. What if you had to sit and look at a cracked or barely readable computer monitor all day? Or what if your television were blurry and dim?

Parker CTC is a candidate for touchscreen repair

Parker CTC Industrial Human Machine Interface (HMI).

That’s what a machine operator suffers through when his touchscreen begins to fail. The human machine interface, or HMI, is the point where man meets machine in industrial controls – the touchscreen. Like most electronic devices, they can and do fail.

What parts fail on touchscreens? What parts are worth fixing? And should you consider buying a new one? All great questions.

Touchscreen Fail Points

Most industrial touchscreen interfaces have four main parts, and failure can occur in any of these parts.

  • touch glass panel
  • the display
  • the main board
  • the power supply

The touch glass panel is the most the common fail item. This is not surprising as it is the section people touch. There are two main reasons they fail and require touchscreen repair. The first and most obvious is when they are physically broken. The second is when the resistive material between the layers of the screen break down from heat or age.

Displays also fail. The modern displays are made of two parts: the liquid crystal display (LCD), and the backlight. Both can fail. The backlights are normally either florescent lamps or LEDs. Like light bulbs, these light sources have finite lifetimes (the LEDs having a longer lifespan). The LCD can fail, too, but not as often as a backlight.

The main board can be as complicated as a computer or as simple as a driver for the display. Either way, they can fail just like any other electronic device.

The power supply, often found on the main board, might be the most important part. Without the power supply, nothing else works. Power supplies normally use electrolytic capacitors because of their small size and cost. Unfortunately, electrolytic capacitors have a drawback: Like lights, they have a finite lifespan.

Yay! Touchscreen Repair is Possible

The good news is almost any failure in a touchscreen HMI can be repaired. The biggest thing that causes a HMI to be unrepairable is a faulty or ruined program. If the program is corrupt and you don’t have a backup, well, that could be an ender.

When would be a good choice to buy a new HMI instead of repairing? first reason is a combination between cost and time. Some HMI’s that were produced in small volumes just do not have parts available. Even though these parts can be custom made, the cost is usually not worth it.

JamesNairn

Nairn

Another reason to buy a new HMI is when your entire system is being upgraded and the choice of a newer HMI (versus trying to upgrade or repair the old one) provides you with newer functionality the old ones just don’t have.

James Nairn is a repair technician for Innovative-IDM in the Houston repair depot. He is also a member of the President's Club for excellence in serving customers and teammates. You can reach him at james.nairn@iidm.com

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Industrial Drive Repair: Replace or Repair?

Posted February 19, 2016 by Pepper Hastings

Categories: Blog, Electronics Repair, Industrial AC Drive, Industrial Electronics Repair

Tags: ,

Industrial drive repair is an important discussion point in most manufacturing facilities. Often, the discussion is whether it’s worth repairing a VFD. Or just buy a new one.

Industrial Drive Repair

Industrial drive repair can be a tricky decision. When should you repair vs. when should you go ahead and replace the VFD? Read more to find out.

VFDs (Variable Frequency Drives) have decreased in price over the years. And with standard VFDs, it’s often economical to replace rather than repair the VFD. A reputable VFD repair company will tell you up front when a drive just isn’t worth repairing.

Many VFDs ARE worthy of repair. Here are some examples where repairing and AC drive might be preferable to replacing it.

When Industrial Drive Repair Makes Sense

It’s a specialized VFD. Some plants have machines worth millions of dollars that have small, very specialized VFDs. Due to communication bus issues, spacing issues (or other application specific reasons) it’s just not feasible to replace them. Innovative-IDM and other reputable repair depots can repair these specialized VFDs and keep the machine running.

It’s a large horsepower unit. The larger the HP, the more likely it is that repairing the VFD is a better option than replacement. For one thing, the installation costs alone on a large HP VFD can be significant, often exceeding the repair costs. We see significant numbers of high horsepower VFD repairs at our repair shop.

Servos. Servo drives are, in general, expensive. They also tend to have application specific software and communication protocols and are often great candidates for repair.

There are large numbers of the specific VFD in the facility. Once you have spares, your maintenance personnel have experience on the units. Now you can use a drive repair company for backup; it might make more sense to stay with what you have and just repair the VFD s rather than replace with new.

We have many customers in this situation. They weigh the cost of the VFD repair, against the TOTAL cost of replacement, which includes things like spares, personnel training, etc.

So, what goes wrong with VFDs?

In general, VFDs are quite reliable. But like any piece of machinery, they have common break points that cause problems, such as:

Loose connections. Don’t laugh, it’s a major cause of VFD downtime. Check simple stuff first. Is a plug on the main circuit board loose? Check your connections before trying a more complex VFD repair.

Cooling Fans. Major cause of problems in industrial drive repair. Some VFD s will let you know about this, but most won’t until you begin tripping on over temperature. The overheating can, and almost certainly will, cause major issues long term. Check your fans often.

Electrolytic Capacitors. These have relatively short lives compared to other components. Overheating shortens it even more.

Power Semiconductors. These are less common, but drastic failures. If this happens, do NOT just replace the IGBT or Diode, find out why if failed. Or, you’ll likely just be replacing it again as soon as you power up.

VFD Software or programming. Was it running before you tried changing a parameter? Then put it all back to where it was and see if that fixes it. Don’t automatically install factory suggested software revisions until you back up what’s running. In general, if it’s running fine now, leave the programming alone.

Circuit boards. These are much less common industrial drive repair failure than one might think, but is often the first thing suspected when an inexperienced technician begins to repair a VFD.

MarcCropwBackground

Phelps

We give firm VFD repair quotes at IIDM and provide free evaluations in our shop. Email me and I’d be happy to discuss your individual situation, or pass you along to one of our technicians for further discussion about whether it’s worth repairing your variable frequency drive, or replacing it with a new one. BTW, did you know that IDM stands for Industrial Drive Maintenance? Isn’t that the kind of repair company you want for your industrial drive repairs?

Marc Phelps is manager of the Innovative-IDM repair facility in Houston. You can contact him at marc.phelps@iidm.com

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Think ‘urgency’ when choosing industrial repair company

Posted January 25, 2016 by Pepper Hastings

Categories: Blog, Industrial Electronics Repair

“A power surge knocked out my equipment. Can you come out tonight?”

If you find yourself on the asking end of this question, you’ll soon find out what kind of industrial repair company you’re dealing with. Power surges happen in facilities and, despite all your protective measures, something electronic and expensive will bite the dust.

Preventivie maintenance

Industrial machine downtime can be minimized with preventive maintenance.

As you weep over the passing away of your too-young-to-die equipment, your facilities production is taking a hit. Even worse if disaster strikes late at night or on the weekend. If only we had implemented a preventive maintenance program, you lament.

Unless your outsourced industrial repair company operates all day, you’ll have to wait until early morning when they open. Every hour your equipment is down, you come closer to breaking commitments as your facility hemorrhages lost productivity.

You need service. And you need it now.

While a good industrial repair service company will be on-scene quickly to repair the issue, a great repair service company is available on-scene ASAP and starts repairs immediately.

For example, when a client suffered a late-night, power issue that destroyed a new A1000 drive, our technician Jon Dutton drove over with a brand new A1000 and installed it the same day.

Client called at 7:30 PM, Jon arrived at 8:30 PM, finished the replacement by 11 PM and was off to another customer appointment at 5 AM that morning.

Customer service should be a top priority for any outsourced industrial repair company you choose. Equipment failures happen and the longer it takes for your equipment to be repaired, the longer you’ll see production drop.

For that reason, keep urgency and customer service quality in the forefronts of the mind when deciding on what repair company to call. Whether it’s with another company or Innovative-IDM's industrial repair field service, your outsourced industrial repair company should strive to provide LEGENDARY customer service. -- Robert Dominguez

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