Once the heat inside the cabinet reaches critical temperatures for the components, component failure results.

One way to cool a cabinet is by electrical fans. Another is air conditioning...yes, that's right. Your control panel might be air conditioned while you sweat your .... off in the maintenance office.

One more way is through venturi cooling, and information from one of the companies that provides those products is right here.

And, if you are in need of a custom control panel, built to your drawings, or if you need one designed and built from scratch, check this out.

Like yourself, I wander around the blog world too, and occasionally find a site that complements this one very well.

I found a site that does that...providing the visitor with a lot of information about electric motors.

Under "Types of Motors" Sawdustmaking.com offers this info.

This motor is used where stops and starts are somewhat frequent. Common applications of split phase motors include: fans, blowers, office machines and tools such as small saws or drill presses where the load is applied after the motor has obtained its operating speed.

Capacitor Start

This motor has a capacitor in series with a starting winding and provides more than double the starting torque with one third less starting current than the split phase motor. Because of this improved starting ability, the capacitor start motor is used for loads which are hard to start. It has good efficiency and requires starting currents of approximately five times full load current. The capacitor and starting windings are disconnected from the circuit by an automatic switch when the motor reaches about 75% of its rated full load speed.

Uses

Common uses include: compressors, pumps, machine tools, air conditioners, conveyors, blowers, fans and other hard to start applications.

If you want more information from their site on electric motors, please click here.

And to get your electric panel questions answered, and a quotation on a custom control panel if you wish, please click here.

Each cabinet can be set up to do a different function, such as setting parts into the system, checking for quality, assembling parts, conveying to another cabinet, and then sorting by color before being offloaded and stored.

The great thing about this system is that a manufacturing process can be prototyped and all the bugs worked out before a company even sets up its manufacturing shop.

Students learn how to design an entire process, thinking wholistically about what has to happen to the parts for them to be assembled correctly. They apply the theoretical skills in mechanics and electricity to program the controllers and make sure that everything moves along smoothly. This also offers hands on troubleshooting skills when the program is not quite right.

Spartanburg Community College Corporate & Community Education has a set of FESTO Mechtronics cabinets installed in the BMW Center at the Tyger River Campus, and a second set that is being made ready for the apprenticeship classes at the Career Technical Vocational Center in Union.  Grant funding from Advance SC and TechReadySC™ has made the purchase of this modern training equipment possible.

The signal to or from the PLC can be in many forms . The typical signal would be 4-20MA (could also be 0-20MA, 0-10VDC). Other examples would be an RTD, a thermocouple, millivolts, etc.

When this signal is an input to a PLC it would be used to monitor devices in the field, such as a flow meter, a pressure transducer, level transmitters, feed back from drives, or any other of the many devices used to measure a process.

When the signal is an output from a PLC it would be used to give a speed reference to a device in the field, such as an inverter or dc drive, a positioning control, regulating valve or any other device that can accept an analog signal as a input to control it.

Analog signals are usually used in a PLC with a PID loop which is a closed loop control.

A typical example of a PID closed loop control would be an input to the PLC from a flow meter and an output from the PLC to an ac drive. The operator or PLC programmer would have entered a set point for the flow into the PLC program. The PLC will compare the flow measurement from the flow meter with the set point and depending upon whether the flow is above or below the set point, will increase or decrease the signal to the drive. The drive in this case is activating a pump and the increase or decrease in signal will result in and increasing or decreasing of flow to bring it closer to the desired flow rate. The further the input is from the set point, the greater the change in output will be.

More about PID loops in another discussion. If you need help with any control challenges, why not ASK JIM?

PLC is the acronym for Programmable Logic Controller. Okay, we can see where the PLC comes from, but then what is a programmable logic controller?

A PLC is a computer similar in concept to, but different from, a desk top or laptop computer. It has internal programs, data storage and input devices like the desktop or laptop computer, but it provides more capabilities than just those basic computers.

The PLC will have the ability to accept incoming information from a variety of devices on a piece of machinery, not just from the mouse or keyboard found on the home computer. The incoming information might be from push buttons, timers, toggle switches, proximity switches; the incoming signal can be from many different sources and these sources can feed information to the PLC through the PLC's Inputs.

Once the PLC receives an input from somewhere, it executes the control program that has been programmed into it by the PLC programmer. This program then may create an output signal of some sort.

The Outputs are part of the PLC as well, and allow a broad range of equipment to be connected to them. As the CPU executes the program, it will send information to the correct PLC Output (if it's been programmed correctly), and that output signal will then cause some other external device on the machine to function.

Even though the PLC has a central CPU (central processing unit) just like the home computer, it differs by having more than just two inputs (mouse & keyboard), and it differs by being able to send control commands out from itself to initiate action somewhere else on a machine.

PLC's are often quite small (in comparison to their P.C. cousins) though those with large numbers of Inputs or Outputs (I.O. points) can get quite large. They are installed inside of a control panel enclosure on or near the machine they control. Wires leading from the various Input devices to the PLC, and those from the Output's of the PLC, enter or exit the enclosure through holes drilled in the enclosure wall.

Control panel enclosures can be made of aluminum, mild steel, stainless steel or fiberglass.

For more information on the various materials, and the gaskets commonly used for seals, please click here and follow the links to Rantro Tips.

PRIMEed Provides:

• On Demand Training through Web Access
• Learning Management System
• Hands on Assessment of Skills
• Reduced Cost of Training

Terril Brown, Instructor 

 A Complete Training Solution: 

• Quickly identify employee knowledge gaps with competency evaluation training
• Deliver anytime, anywhere maintenance technician training
• Manage and track employee progress using an integrated learning management system
•  Validate  employee skill sets through hands-on performance evaluations

Learning Management System
Primedia can

• define curriculum
• monitor employee progress
• inform employees of next step
• email messages to employers
• issue certificates of completion
• Produce reports on training status

Enrollment is easy. Let us know who you would like to enroll in the industrial maintenance technician training program and we will handle the details: employee notification, competency evaluations, curriculum development, course offerings, scheduling of hands on performance evaluations,  as well as overall tracking, reporting and managing.  Call Rita Hunt at (864) 592-4751 for more information.

See Also: Electrical  Industrial Maintenance   Quality Assurance / Lean Manufacturing  Supply Chain  Amatrol©

We've been reviewing the specifications of the various NEMA ratings in this series of blogs, and this is the last, where we'll review ratings 6-13.

If you need more information about machine control panels and accessories, why not Ask Jim?

NEMA 6

NEMA 6 enclosures have to be constructed for use either indoors or out, must provide a degree of protection against persons accidentally being able to come in contact with equipment inside the pane. NEMA 6 also means the panel will provide protection against falling dirt, hose-directed water, and will prevent the entry of water into the panel should it be temporarily submerged at a limited depth. Contents and the panel must remain undamaged by the build up of external ice on the panel enclosure.

NEMA 6P

All the same conditions as NEMA 6, but this panel must prevent the ingress of water if the panel has a prolonged submersion at a limited depth.

NEMA 7

A NEMA 7 enclosure is used indoors in locations with classifications as Class I, Groups A,B,C, or D, and shall be capable of withstanding the pressures resulting from the internal explosion of specified gases, and must contain such explosion sufficiently that an explosive gas-air mixture existing in the atmosphere surrounding the panel enclosure will not be ignited. Any enclosed heat generating devices shall not cause external surfaces of the panel enclosure to reach temperatures capable of igniting gas-air mixtures in the surrounding atmosphere. NEMA 7 enlcosures shall meet explosion, hydro-static and temperature design tests.

NEMA 9

The are panel enclosurs intended for use indoors, in locations classified as Class II, Groups E, F, or G, and shall be prevent the entrance of dust. Any enclosed heat generating devices shall not cause external surfaces of the panel enclosure to reach temperatures capable of igniting or discoloring dust on the surface of the enclosure, or igniting dust-air mixtures in the surrounding atmosphere. Enclosures must meet dust penetration, temperature design tests, and aging of gaskets if used.

NEMA 12

These are enclosures construction (without knockouts) to be used indoors, and to provide a degree of protection to persons from incidental contact with enclosed equipment. They must also provide a degree of protection against falling dirt, circulating dust, against lint fibers, and dripping or splashing of liquids.

NEMA 12K

Offers all the same protections as NEMA 12, these enlcosures have knockouts.

And last but not least....

NEMA 13

These are enclosures for indoor use, and to provide a degree of protection to persons from incidental contact with enclosed equipment. They must also provide a degree of protection against falling dirt, circulating dust, against lint fibers, and against the spraying, splashing, and seepage of water, oil and non-corrosive coolants.

Learn at your own pace at home the skills required  for a career in industrial maintenance through a web-based  maintenance program.  Computers are available at the Cherokee Campus, if you don't have a computer at home. It's a sweet deal. The online programs are presented as videos with clear explanations and demonstrations, so you will be well-prepared for the hands-on labs that show what you have learned.

Schedule visits to our lab to work with instructors for hands-on experience and skill assessment.

Learn about:

• mechanical drives
• shaft alignment
• hydraulics
• pneumatics
• machine tools
• basic electricity
• motor controls
• machine drives
• PLCs
• HVAC

To enroll in the program contact:

Terrill Brown
864-206-2805 or 864-592-6167

In our continuing blogs about NEMA ratings for electrical enclosures, today we'll look at the NEMA 4 and 5 ratings. NEMA rates panels on a scale of specification numbered 1 through 13, with numbers 1, 4 and 12 normally used for panels.

NEMA 4

To be classified as a NEMA 4 panel, the enclosure must be constructed for either indoor or outdoor use, to provide a degree of protection to prevent incidental contact to enclosed equipment by any personnel, to provide a degree of protection against falling dirt, rain, sleet, snow, windblown dust, and splashing or hose directed water. The enclosure must remain undamaged by the external formation of ice on it. NEMA 4 panels are normally constructed of painted carbon steel.

NEMA 4X

To be classified as NEMA 4X, the panel must provide all the protection as noted in NEMA 4, as well as provide protection of the panel enclosure itself from corrosion. NEMA 4X panels will normally be constructed of stainless steel, or fiberglass.

NEMA 5

A NEMA 5 classified panel provides a degree of protection to personnel against incidental contact with the enclosed equipment, and to provide a degree of protection against falling dirt, settling airborne dust, lint, fibers, and dripping or splashing of liquids.

Need more information about machine control panels? Click here.

We use a NEMA rating to identify the particular protection level of Machine Control Panel Enclosures.

NEMA ratings for control panel enclosures number 1 through 13 although the common ratings for enclosures are NEMA 1, 4 and 12. In this blog we will review the various control panel enclosure ratings.

NEMA 1
This is the lowest NEMA protection rating for a control panel enclosure. In order for the panel box to be considered as NEMA 1, it must provide a basic level of protection from persons coming into incidental contact with the contents of the panel box, and it must provide protection from the panel box contents being exposed to incidental contact with falling dirt.

Panels with NEMA 1 rating are general purpose because they lack gaskets. They should only be used indoors in a dry location.

NEMA 2
A panel with NEMA 2 rating must provide the protection as outlined under the NEMA 1 standard as shown just above, as well as providing protection for the panel contents from dripping or splashing liquids.

When electric motors are operated they generate heat. Some motors generate lots of heat (probably those that don't show the motor efficiency on the plate) and some less so.

Heat generation by the motor indicates a of loss of energy, as the electricity is being used to generate heat rather than rotation. The more heat the motor generates, the less efficient it is in turning electricity into rotary motion.

Motors with higher efficiency ratings likely have more metal in their construction. Insulated metal is placed between the laminations to reduce eddy currents that produce energy wasting heat.

If you have an efficiency rating on the motor data plate of your motor, you will see a rating in percent, as in 86%, or you might see it as a decimal, as in .86.

When purchasing a motor, higher efficiency motors will reduce operating costs.

This entry is about Locked Rotor Amps.

Locked Rotor Amps are the amount of power that this motor will draw when it's starting or when it's attempting to start but cannot.

It might not start because the bearings have seized, for example.

An electric motor is considered "locked" any time the rotor isn't rotating. If a start is attempted but the motor cannot for a mechanical reason rotate, the motor will be in locked rotor amp.

Therefore, the LRA (locked rotor amperage) of an electric motor is the maximum amount this motor will draw when it's attempting to start, regardless of the condition of that motor.

FLA is the current that this particular motor will draw when the load on the motor reaches it's rated horsepower.

The motor will draw less than it's FLA if the motor is loaded at less than it's rated horsepower, and will draw more FLA's when it's loaded higher than it's rated horsepower.

Measuring the amps a motor is drawing and comparing those to it's FLA will quickly tell you if the motor is being overloaded in the application.
If you have a question about control panels, motor controls, industrial wiring, get help from a pro. Ask Jim!

Next blog we'll look at Locked Rotor Amps.

Voltage
One of the boxes on the information plate is marked Voltage. The number in this box identifies the design voltage for that particular motor.

The electric motor may be operated safely at any voltage that is within plus or minus 10% of the number shown in the Voltage box.

Got an industrial electrical or machine control question? Ask Jim!

What's FLA (Full Load Amps) mean? That's for the next blog.

The number assigned to a motor indicates how much more work a motor can be expected to provide over and above it's rated horsepower.

An SF (service factor) of 1.15 means that a 1 HP motor can do work up to 1.15 HP for a period of time.

The motor service factor should not be used in the installation, but rather, is a safety factor to be used when the load temporarily exceeds the nominal rating of that motor. Here's more information.

This site addresses part of that by providing informative comments about machine controls, the hows, whys, and pitfalls of controlling industrial equipment using PLC's and control panels.

You want to keep this blog on a feed for the information it will provide.

"Maintenance is like a puzzle," says Marvin Tedder, apprenticeship instructor. "We like to do puzzles. It's a challenge between you and the machine. The machine is broken--what has the machine done to break itself? How do you get the machine to do what you want it to do? "

Apprentices get a well-rounded introduction to electricity, mechanics, motor controls, pneumatics, hydraulics and electronics in a high tech lab at the SCC-BMW Center at the Tyger River Campus in Duncan. A Festo Mechatronics trainer system, two Mitsubishi robots, industrial style electricity panels and PLC controllers are available in the lab.  Apprenticeships are designed to provide the company with highly competent technicians for better operations. Assisted by the Work Investment Board (WIB), companies release workers to train two days a week. Workers want to make better pay, but they are also concerned with the smooth operation of the plants where they work. They want to be more productive. 

 Some classes also include, as this one does, individuals who are studying on their own, such as Bob Quattlebaum, who retired from management after 35 years at  Cryovac. His goal is to give back to the community, and he uses his new skills to help the Habitat for Humanity program as an electrician.

Genaro Bautista and Donald Dover work at Goodyear. Today Bautista has come to class on his day off to work on his project. When he is scheduled to work on class days, he comes to class unless there is a problem in the plant. Donald Dover studies an electronics diagram in class at the SCC-BMW Center. "When we can fix problems, it benefits the company, " Dover says. "If we have to call in the outsource company, they may not get there until six in the morning. We are already there, and we can deal with the problem. It keeps the money in the plant."

Roger Morris, a technician at Barnet Polymer,  says the well-rounded electrical and mechanical apprenticeship training was "something I just couldn't pass up, though it's not easy to work twelve hour shifts and then come to school. "

James Williamson works at Mrs. Smith's Bakery. He is already familiar with the PLC's used there. "The machine will throw a fault," Williamson says, " It's like the machine gets confused. We have to take the laptop in there and clear the fault to get the machine going again. It has more uptime when we can take care of it."

Spartanburg Community College helps local businesses with the registered apprenticeship application process, which is a contract between the business and granting agencies to help build a stronger, better-trained workforce for the Upstate Area. An additional eight companies are partnering with SCC for WIB and AdvanceSC funds to upgrade the skills of their workers. European companies have used apprenticeships for years to build their workforce, and now this model is available to SC companies as well.

Randy Clark, a consultant from Kentucky Community and Technical Colleges (KCTC) , presented the Siemens Mechatronics training model at the SCC-BMW Center on Tuesday and Wednesday. Representatives from Greenville Technical College, Piedmont Technical College, and Spartanburg Community College learned about how KCTC has built its programs using this model, and the instructor training that they offer in the US.  Other states investigating this model are Ohio, Florida, Texas and Missouri.

Siemens is the largest manufacturing company in the world, after General Electric. In fact, the Siemens company is larger than the manufacturing division of GE. Standardizing the training assures that students will have the well-rounded knowledge, skills and mindset necessary to be effective operators, maintenance technicians and managers.

Siemens has a word for the qualities that a good technician should have: hanslungkompetenz, which means that a peson can adapt to a new work environment quickly and appropriately.

The skills learned in this platform are transferable to any manufacturing process with any brand of equipment. The curriculum is designed to teach students to consider the whole system and how indvidual components work together, rather than teaching each piece in isolation.

Festo' educational platform has several requirments:

• Program must be taught in English, regardless of the national language where the training will be done.
  Currently programs are being taught in China, Denmark, and France as well as Germany. The Stuttgart training facility chooses 50 trainees from 2000 applicants each semester.
• Training facility must have Mechatronics trainers installed for hands on work in class.
• Instructors must be certified with Paradigm training in Berlin for one week, with one more week of specific
  training in systems-oriented lesson design. The tuition includes housing and travel within Germany, but not food or airfare.
• Schools must be accredited through an appropriate organization such as SACS (Southern Association of Colleges and
  Schools).
• The school must have a local Siemens plant, or in the US, the school will be a partner with Siemens Atlanta
  or the home office of Siemens in Germany.

Three levels of training have been designed. Level One, for operator-technicians, has been taught in high school as an vocational specialization program and as a one-semester certificate program in two-year colleges either for credit or as continuing education. After completing the class, the student takes a standarized, written test online through a third party provider. On passing the test, the student receives international certification to operate mechatronics equipment.

Level One operators should be able to

• Be responsible for efficient operation of machinery/ workstation
• Do routine preventive maintenance and predictive maintenance
• Use system documentation intelligently
• Work as an effective member of a manufacturing team
• Observe all local and company safety regulations

Level Two maintenance technicians would also be able to investigate, troubleshoot and repair complex manufacturing systems. An associate degree might include both Level One and Two, along with general education courses. This test requires both written and hand-on demonstrations.

Level Three is for maintenance management, and would be taught as part of a bachelor's program. The Siemens platform assures that credits for the first two Mechatronics classes would transfer.

SCC instructors Tim Coggins and Mark Spencer have already attended the Festo Mechatronics training in Stuttgart in preparation for instructing students in the Union County Robotics Training Facility.

Job Fair at completion of class.  

* To complete an application and register for an assessment visit:
Career Source
103 West Main Street
Union, S.C.
Applications accepted 3 Days Only:
December 3th and 5th, from 9 a.m. - 2 p.m.
December 4th, from 3 p.m. - 7 p.m.
Call: (864) 427-4119 for details

* Assessments can be taken multiple times and remediation is available
www.sccsc.edu/cce