Micromaster 420

Siemens Micromaster 420 Faults and Alarms

Siemens Micromaster 420: Troubleshooting Faults and Alarms

A blog we posted earlier this week about the Micromaster 420 troubleshooting referenced the Faults and Alarms list for the Micromaster series, so we decided that it would make sense to make the list of Micromaster 420 Faults and Alarms directly available. This is from the corresponding manual for the Micromaster 420 series, but it is buried within the manual which most people most likely don’t even have. Hopefully, this helps with your troubleshooting of Siemens drive fault codes and alarms.

Be sure to also check out our list of Siemens Micromaster 440 fault codes and our article touching on Siemens Simodrive E/R Module Fault Troubleshooting, along with other Siemens series coverage.

If you’re looking to purchase a Siemens Micromaster drive, view our 420 Micromaster Drives in stock. For more information or to request a quote, please call 800-691-8511 or email sales@mroelectric.com. We also provide pre-priced Micromaster 420 Repairs.

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Digitalizing Automation For the Future

A Brief History

For the longest time, automation has always been the end-goal process when it comes to industrialization. That is that the user can quickly and efficiently complete a process repeatedly. Whether that process involves production or maintenance, the last two decades have seen a monumental rise in digitalization across numerous industries. Of course, digitalization is not a stranger to the world of automation machinery (and it would be incorrect to conflate that one is the opposite of the other). As it stands, all of the major industrial companies have some form of proprietary software that they use to automate their machinery and it’s been that way for several decades. However, in research done by Forrester, 77% of businesses today still rely on a paper process, with only 63% still using spreadsheet programs. Ultimately, this makes it more difficult to keep up with customer demands, and really wanting for a more streamlined process.

Automation and Digitalization

What is Automation?

Automation physically performs a process without the constant need of a human operator. Its tasks are dedicated by a group of rules preset by an operator usually in the form of either script commands or more robust software pending on what the task is.

What is Digitalization?

Digitalization is basically the process of taking a hard copy of something and converting it into a digital format. This could be anything from a worded manual or even a photo. Digitalizing is crucial to automation because it is how an automated process interprets data to commit to a function. The last few decades have seen a progression in the control of industrial automation from manual to digital.

The Possibilities

One example of how digitalization can streamline automation is through the way tasks and functions are being given to a piece of industrial equipment. For the longest time, equipment like automoted robots in manufacturing have been relying on external devices like PLCs (Programmable Logic Controllers) to output individual commands. These are all multiple components linked together on a bus and then connected to the drive and other components. This is the current setup for a lot of industrial and manufacturing operations.

While this setup does get the job done, it does present a few issues.

For starters, communication is one of the most important things when automizing. When multiple components come into play, there is always the chance of communication issues between devices. This can be attributed to various issues, like conflicting software between the devices or even simply how something is connected. There is also the issue of troubleshooting and trying to figure out the cause of an existing issue. With digitalization, instead of having a bunch of devices trying to talk to one another, there can be just one fully-integrated device using a single software. Having instant diagnostics would also cut down on troubleshooting time.

A Little Thing Called BIM

One piece of digitalization that could potentially change the way automation works is actually a technology that is becoming more prominent in the field of architecture and engineering called BIM (Building Information Modeling). What is BIM? In short, BIM is a digitalized way to create and manage data in the design, construction, and operation of products. Often it is used by architects, engineers, and construction working on sophisticated buildings. It allows for multiple teams to collaborate in real-time as they are working on a project. The same technology could virtually model the layout of a factory and could share accurate data in real-time across multiple teams.

Imagine an entire manufacturing setup being represented by a virtual model that is constantly sharing diagnostics of the equipment. If something were to break down or get faulty, the diagnostic could alert the technician, and using the virtual model, they can get a better visual representation of what is causing the issue and where it can be found. Simultaneously an alert can be sent out across different departments so that different teams can quickly communicate and come up with solutions to the problem. This in turn saves time on labor and the cost of troubleshooting.

Final Thoughts

Automation has always been and continues to be the end goal for many companies across multiple industries. With digitalization allowing for the process to function more autonomous than ever, it seems we are moving further along into a world of unfettered interconnectivity. As the digitalization of automation continues to progress, the acknowledgment of anxiety over its effects on human employees cannot be ignored. If everything is fully automated and more streamlined, what place does the employee have?

One issue that we need to consider is how automation will affect socioeconomics. From an optimistic point of view, one could argue that the present automation has already done away with a lot of the ‘human element’, and the margins of laying off workers would be small, especially when a company could train up employees to learn the technology.

On the other hand, we’re talking about a situation where only a handful of positions are available. Often, a company would rather onboard someone who already has experience rather than train an existing employee. Automation could pessimistically mean that both low-skilled and specialized employees both have a hard time finding work. On one end when most of the general tasks can be automated why would a company need to hire humans? Not to mention that exists a ceiling with just how many specialized jobs exist versus how many specialized employees compete to fill those seats. This is an existing issue we can see across multiple tech sector positions today.

What the solution is, remains to be seen. While the advancement of automation is crucial to productivity, it is something that should be treated cautiously in regards to how it affects the working person.

title graphic of “Comparing Gas Prices to Minimum Wage in Cities Around the U.S.”

The US Minimum Wage vs Gas Price Inflation Compared

With no ceiling in sight for the climbing gas prices around the nation, many Americans are forced to adjust both their driving and spending habits to keep pace. Plus, with the holiday season in full swing, Americans need to account for higher airfare, food costs, and hotel prices as they plan their vacations, which may mean trips closer to home. Gone are the days of purchasing gas for under $2.00 per gallon. We now live in an era, where the price per gallon exceeds the federal minimum wage in certain locations––talk about pain at the pump. 

Minimum wage workers and low-income commuters are suffering the most as a large percentage of their paychecks are being ravaged by rising gas prices.  In California, a 12-gallon tank of gas costs minimum wage workers in some areas nearly 57% of a day’s pay. In some states like Pennsylvania and Utah, gas prices continue to rise, while minimum wage still sits at $7.25 an hour––where it’s sat for the last ten years, despite growing inflation rates. 

To uncover where soaring gas prices are taking the biggest bite out of workers’ paychecks, MRO compared the minimum wage to the mean gas price in 100 U.S. cities. We dug deeper, focusing on 18 cities where gas costs over 80% of a minimum wage employee’s paycheck, ushering in a dystopian-like society all over the U.S. Read on to see where your city and state stack up.

What Causes Gas Prices to Go Up?

Low prices at the pump in our pre-pandemic world weren’t just a fever dream. If you remember, the demand for oil drastically fell during the pandemic as the world shut down and people were forced to stay home, but as the U.S. slowly started to recover, the demand for oil rebounded once more. The only problem? Oil production came to a grinding halt and drilling new oil wells takes a lot longer than ordering a new outfit through Amazon Prime. Plus, inflated energy prices, transportation costs, and a U.S. ban on purchasing oil from Russia all factor into soaring oil costs. 

Why Is the Minimum Wage so Low?

The minimum wage was last raised thirteen years ago to $7.25 per hour on July 24, 2009, and it’s no secret that this amount has not kept up with inflation. Certain places like New York City have taken steps to raise the minimum wage for fast food workers to $15.00 per hour, but not every state and city has followed suit, leaving many wondering how they can survive and stretch their paychecks. 

The minimum wage is indexed in 18 states and adjusts to keep up with inflation, but even this can vary depending on the individual counties within the same state. While President Biden did use executive order privileges to raise the minimum wage to $15.00 per hour for federal workers, republican and democratic lawmakers still can’t reach a resolution that satisfies either party’s agenda. With other pressing matters coming to a head, it’s not clear when or if a raised minimum wage that accounts for the rising cost of living will ever be ratified into law in the near future. 

Can Minimum Wage Workers Afford the Gas Prices for Their Commute?

a U.S. map displaying the cities with the largest difference between minimum wage and gas prices

According to study results, minimum wage workers who make $5.15 per hour in Atlanta, GA pay $3.80 on average for a gallon of gas, resulting in 110.6% of a day’s paycheck being eaten by a full tank of gas (12 gallons). If the average commute in the U.S. requires 1.28 gallons of gas, then these Atlanta workers would lose wages just by showing up to work. 

A full tank of gas consumes 93.1% of a day’s pay in cities like Boise City, ID, and it isn’t much better in places like Salt Lake City, UT, where 92.3% of a hard earned day’s wages is budgeted towards a full tank of gas. Those in Philadelphia, PA lose out on 85.9% of their paycheck towards a full tank. Minimum wage workers are stuck in a catch-22, but certain restaurant owners in Philadelphia are promising to raise their hourly wage to $15 per hour, creating light at the end of the tunnel. 

Some customers are willing to pay higher menu prices to accommodate a living wage, and with the City of Brotherly Love welcoming 36.2 million visitors in 2021 alone, let’s hope this hot spot tourist destination can back these restaurant owners’ selfless initiatives.

Out of the top 18 cities where gas costs over 80% of a minimum wage worker’s paycheck, Pennsylvania holds five of those seats in places like Scranton (87.3% of a day’s pay), Pittsburgh (86.9% of a day’s pay), Harrisburg (86.4% of a day’s pay), and Allentown (85.5% of a day’s pay). The oil refinery explosion that occurred in South Philly in 2019 has forced the state to rely on imports more than ever before, contributing to the rising cost of gas. 

Popular tourist destinations like New Orleans, LA, and Memphis, TN, are seeing skyrocketing gas prices at the pump. New Orleans minimum wage workers sacrifice 81.7% of a day’s pay to a gallon of gas while Memphis workers follow closely behind at 81.0%. Taking a trip to day drink at New Orleans’ historic bars? Avoid soaring gas prices and careen around the city on foot or with their bike share program.

The 5 States With the Largest Difference Between Minimum Wage and Average Gas Prices


an infographic showing how many gallons of gas minimum wage workers in Washington can afford with one hour of work

Next, we found the five states with the largest difference between minimum wage and average gas prices. Topping the list is Washington state. With a minimum wage of $14.49 and the average price per gallon of gas at $4.23, minimum wage workers in Spokane, WA can purchase 3.43 gallons of gas with one hour of work. Minimum wage workers in Seattle, WA can purchase 3.00 gallons of gas with one hour of work. What’s more, a full tank of gas (12 gallons) costs minimum wage workers in Seattle, WA 50.1% of their pay that day.


an infographic showing how many gallons of gas minimum wage workers in Massachusetts can afford with one hour of work

With a minimum wage of $14.25 and the average price per gallon of gas at $4.12, minimum wage workers in Boston, MA can purchase 3.46 gallons of gas with one hour of work. Additionally, a full tank of gas costs minimum wage workers in Boston, MA over 43% of a day’s pay.


an infographic showing how many gallons of gas minimum wage workers in Connecticut can afford with one hour of work

In Connecticut’s capital, Hartford, minimum wage workers can purchase 3.40 gallons of gas with one hour of work. In New Haven, CT, home of Yale University, that number drops to 3.35 gallons. Therefore, a full tank of gas costs minimum wage workers in Hartford and New Haven nearly 45% of a day’s pay.

New York

an infographic showing how many gallons of gas minimum wage workers in New York can afford with one hour of work

With a minimum wage of $13.20 and the average price per gallon of gas at $4.27, minimum wage workers in Rochester, New York can purchase 3.09 gallons of gas with one hour of work. Minimum wage workers in Buffalo, NY, and Albany, NY could purchase 3.13 and 3.17 gallons of gas, respectively.


an infographic showing how many gallons of gas minimum wage workers in Maryland can afford with one hour of work

In Baltimore, MD, minimum wage workers can purchase 3.41 gallons of gas with one hour of work. Additionally, a full tank of gas costs minimum wage workers in Baltimore almost 44% of their pay that day.

Are There Any Signs of Relief on the Horizon for Minimum Wage Employees?

While minimum wage workers protest all over the country to get their voices heard, they still face an upward battle in this ongoing fight, despite there being a majority of Americans who are in favor of raising the minimum wage to $15.00 per hour. Governors in certain places like Pennsylvania are putting pressure on the General Assembly for a living wage and relief for their constituents. One survey found that while Republicans do agree the minimum wage should be increased, most would prefer raising it to $11.00 per hour, instead of $15.00. As states, cities, and local counties possess the authority to raise the minimum wage, this fight may need to be taken to the lower levels of power, instead of advocating for a living wage on a national scale, where it may find less success.

Gas Prices and Stagnant Minimum Wages Continue to Affect Consumers

That wraps up our study, comparing gas prices to minimum wage amounts around the U.S. Gas prices continue to be a dire issue across the country in 2022, as well as a harrowing expense for lower-income Americans who are also struggling to keep up with rising food prices and housing costs. 

While MRO Electric can’t control the cost of gas, we can offer the parts and equipment you need to keep things getting from A to B. Get in touch with us today by emailing sales@mroelectric.com or calling us at 800-691-8511 for a quote.

Research Methodology

Using data from the U.S. Department of Labor and GasBuddy, we collected the minimum wage in each state and the mean gas price in 100 U.S. cities in April 2022. We divided the minimum wage in each state by the average gas price in each city to determine how much gas a minimum wage worker can purchase with one hour of work. For all minimum wage amounts by state, we collected the basic minimum rate per hour, as listed by the Department of Labor. Gas prices are always fluctuating, so prices may differ from the time frame the data was pulled.

Siemens Sinamics CU320 Modules: Beyond the User Manual

About Sinamics S120 CU320 Modules

There are two Sinamics S120 CU320 Modules. There is the CU320-2 DP, which is the 6SL3040-1MA00-0AA0, and the CU320-2 PN, which is the 6SL3040-1MA01-0AA0.

These multi-drive Control Units increase axis count and functionality. They have an Ethernet port, as well as more I/O and controller to controller communication. Each unit can manage up to 6 servo or vector axes in a high performance system. For standard systems, up to 12 V/Hz axes can be controlled from one CU320-2 unit. These Control Units significantly reduce system costs, as they increase functionality for positioning, safety integration, and drive control allowing all these functions to be controlled by one unit versus several.

Siemens CU320 control units also provide additional flexibility with a high number of programming options and digital inputs. With up to 12 binary inputs, the modules’ high I/O count add ease of use. The additional Ethernet port expands programming options as well. Overall, the CU320-2 control units allow for simple yet flexible performance with minimal cost and space requirements.

If you want to learn more about these high-performance drives, check out our blog on Sinamics s120 fault codes.

CU320-2 DP Module

CU320-2 DP

The CU320-2 DP is a Sinamics Control Unit with a Profibus interface. It is a central Control Module in which the closed-loop and open-loop functions are implemented for one or more Line Modules and/or Motor Modules. It can be used with firmware version 4.3 or greater. It has 12 digital inputs, 8 digital inputs/outputs, 4 DRIVE-CLiQ interfaces, a Profibus and Ethernet interface, a serial interface (RS232), an option slot, and 3 measuring sockets.

MRO Electric stocks new and refurbished CU320-2 DP Control Units, which is part number 6SL3040-1MA00-0AA0. If you would like a replacement module, please call 800-691-8511 or email sales@mroelectric.com.


CU320-2 PN Module

CU320-2 PN

The CU320-2 PN is a Sinamics S120 Control Unit without a Profibus interface. It has the same interfaces as described above, however without the Profibus port. It is also a central control unit with closed-loop and open-loop functions that can be implemented for one or more Line or Motor modules.

MRO Electric stocks new and refurbished CU320-2 PN Control Units, which is part number 6SL3040-1MA01-0AA0. If you would like a replacement module, please call 800-691-8511 or email sales@mroelectric.com.

Sinamics S120

Sinamics S120 Fault Codes and Alarms, Part I

It is important to understand the differences between faults and alarms on Sinamics S120 Drives by Siemens. We have included a list of common faults and alarm codes for S120 drives, what they mean, likely causes and how to fix the fault or alarm. For more Sinamics S120 faults and alarms, check out Part II and Part III of the series that we will be posting shortly. Be sure to check out our website to browse all of our Siemens products.

Understanding Faults 

What happens when a fault occurs?

  • The appropriate fault reaction is initiated
  •  Status signal ZSW1.3 is set.
  • The fault is entered in the fault buffer.

How are faults eliminated?

  • Remove the original cause of the fault
  • Acknowledge the fault

Understanding Alarms

What happens when an alarm occurs?

  • Status signal ZSW1.7 is set.
  • Alarms are “Self Acknowledging” meaning they are reset when the cause of the alarm has been eliminated.

List of Sinamics S120 Faults and Alarms

F01000:  Internal software error

Message Value: Module: %1, Line: %2
Drive Object: All Objects
AcknowledgePOWER ON
Cause: An internal software error has occurred. Fault value (r0949, interpret hexadecimal)

  • Evaluate fault buffer
  • Carry out a POWER ON (power on/off) for all components.
  • If required, check the data on the non-volatile memory (memory card).
  • Upgrade firmware to a later version.
  • Replace the control unit or contact MRO Electric.

F01001:  Floating Point Exception

Message Value: %1
Drive Object: All objects
Reaction: OFF2
AcknowledgePOWER ON
Cause: An exception occurred during an operation with the FloatingPoint data type. The error may be caused by the basic system or the OA application (e.g. FBLOCKS, DCC).

  • Carry out a POWER ON (power on/off) for all components.
  • Check configuration and signals of the blocks in FBLOCKS.
  • Check configuration and signals of DCC charts.
  • Upgrade firmware to a later version.
  • Contact Service Hotline.

F01002:  Internal software error

Message Value: %1
Drive Object: All objects
Reaction: OFF2
Acknowledge: IMMEDIATELY
Cause: An internal software error has occurred

  • Carry out a POWER ON (power on/off) for all components.
  • Upgrade firmware to a later version.
  • Contact Service Hotline.

F01003:  Acknowledgement delay when accessing the memory

Message Value: %1
Drive Object: All objects
Reaction: OFF2
Acknowledge: IMMEDIATELY
Cause: A memory area was accessed that does not return a “READY”.

  • Carry out a POWER ON (power on/off) for all components.
  • Contact Service Hotline

N01004 (F, A):  Internal software error

Message Value: %1
Drive Object: All objects
Reaction: NONE
Acknowledge: NONE
Cause: An internal software error has occurred. 
Remedy:  Read out diagnostics parameter (r9999).
Reaction upon F: OFF2
Acknowl. upon F: POWER ON
Reaction upon A:  NONE
Acknowl. upon A: NONE

F01005:  Firmware  download for DRIVE-CLiQ component unsuccessful

Message Value: Component number: %1, fault cause: %2
Drive Object: All objects
Reaction: NONE
Acknowledge: IMMEDIATELY
Cause: It was not possible to download the firmware to a DRIVE-CLiQ component

  • Check the selected component number
  • Check the DRIVE-CLiQ connection
  • Save suitable firmware file for download in “/siemens/sinamics/code/sac/”
  • Use a component with a suitable hardware version
  • After POWER ON has been carried out again for the DRIVE-CLiQ component,                               download the firmware again. Depending on p7826, the firmware will be                                       automatically downloaded.

A01006: Firmware update for DRIVE-CLiQ component required

Message Value: Component number: %1
Drive Object: All objects
Reaction: NONE
Acknowledge: NONE
Cause: The firmware of a DRIVE-CLiQ component must be updated as there is no suitable firmware or firmware version in the component for operation with the Control Unit.
Alarm value (r2124, interpret decimal): Component number of the DRIVE-CLiQ component

  • Firmware update using the commissioning software: 
    • The firmware version of all of the components on the “Version overview” page can be read in the Project Navigator
      under “Configuration” of the associated drive unit and an appropriate firmware update can be carried out.
  • Firmware update via parameter:
    • Take the component number from the alarm value and enter into p7828.
    • Start the firmware download with p7829 = 1.

A01007: POWER ON for DRIVE-CLiQ component required

Message Value: Component number: %1
Drive Object: All objects
Reaction: NONE
Acknowledge: NONE
Cause: A DRIVE-CLiQ component must be powered up again (POWER ON) (e.g. due to a firmware update). 

Alarm value (r2124, interpret decimal): Component number of the DRIVE-CLiQ component. If the component number is 1, a POWER ON of the Control Unit is required. 

  • Switch off the power supply of the specified DRIVE-CLiQ component and switch it                   on again.
  • For SINUMERIK, auto commissioning is prevented. In this case, a POWER ON is                           required for all components and the auto commissioning must be restarted.

A01009 (N):   CU: Control module overtemperature

Message Value: –
Drive Object: All objects
Reaction: NONE
Acknowledge: NONE
Cause: The temperature (r0037[0]) of the control module (Control Unit) has exceeded the specified limit value.

  • Check the air intake for the Control Unit.
  • Check the Control Unit fan.

MRO Electric and Supply carries new and used Sinamics modules. For more information or to request a quote, call 800-691-8511 or email sales@mroelectric.com.

KUKA Robot Arms | Available Now at MRO Electric and Supply

KUKA Robotics

Updated August 2019: You can purchase KUKA products directly from our website.

MRO Electric and Supply distributes a variety of new and refurbished KUKA Robot arms.

We repaint and rebuild all of our refurbished robotics arms, as well as purge and replace the grease according to the manufacturer’s specifications.

KUKA Robot Models

We supply KUKA arms and wrists from a number of robots. We have included some popular KUKA robot models in our inventory below:

  • KR30
  • KR60
  • KR90
  • KR150
  • KR180
  • KR360
  • KR500
  • Any Many More!

About KUKA Robotic Arms

Most KUKA robotic arms are made up of 4-6 joints, and can be used for many different applications such as welding, material handling, material removal, and more. Their large arms are typically used to lift heavy payloads and are sometimes run by hydraulic and pneumatic methods. Most KUKA robot arms are made from aluminum and built from the base up, ending with the wrist and whichever end effect is needed to help the arm perform its given application.

KUKA was one of the first companies to use aluminum in robot arm design, which makes KUKA manipulators one of the fastest and lightest on the market. They also introduced a horizontal balancing spring on axis 2 before the other robot manufacturers, a design that has now been widely adopted.

Even if you are new to programming, you can explore different intuitive programming options to find out what will work best for you. KUKA robotic arms can be programmed in multiple ways including using KUKA’s own robot language, through hand guiding, a handheld probe, graphical offline programming and more.

MRO Electric and Supply has a warehouse full of many types of KUKA arms and wrists. Give us a call today if you need a replacement and we can usually ship you one same-day! You can also email sales@mroelectric.com for a quote.

How Does a Relay Work?

What Is a Relay?

A relay is an electrically controlled switch that has the ability to turn a circuit on or off. Depending on the application relays can do a number of things. Relays can be used as switches to turn things on and off, or as amplifiers to convert smaller currents into larger ones. They can also be used to control a circuit with a low power signal or when multiple circuits need to be controlled by a single signal.

There are two kinds of relays, electromechanical and solid state. In this post, we will be focusing on electromechanical relays and how they work.

Basic Parts of a Relay

Armature– is a basic metal piece that is balanced on a pivot or a stand. It is considered the moving ‘arm’ of the relay. It makes or breaks the connection with the contacts connected to it.

Spring– is connected to one end of the armature and pushes the armature back into place if no current is passing through.

Electromagnet– is a metal wire wrapped around a metal core. The wire does not have magnetic property but can be converted into a magnet with the help of an electrical signal.

Yoke– is a small metal piece affixedon a core which attracts and holds the armature when the coil is energized.

Contacts– conductive material that exists within the device whose physical contact opens or closes a circuit

A break refers to the number of locations on a circuit that a switch can make or break the flow of current. In electromechanical relays, there can be single breaks and double breaks. A single break is usually used with low power devices while a double break is usually used with high power devices.

A pole refers to the number of circuits that relays can pass through a switch. A single pole contact carries current through one circuit, while a double can carry it through two.

A throw refers to the number of separate wiring paths. For example, a triple throw switch can be connected to one of three contacts instead of one.

How Do Electromechanical Relays Work?


In an electromechanical relay, a small circuit has the ability to switch a larger circuit on or off through contacts by using an electromagnet. Some contacts come in different configurations depending on the use of the relay, namely, normally open relays and normally closed relays.

With a normally open (NO) relay, contacts are open when there is no current passing through. Once power is presented, the electromagnet will be activated. When charged, the electromagnet creates a magnetic field that attracts the armature and closes the contacts.

With a normally closed (NC) relay, contacts are closed when there is no current passing through. Unlike normally open relays, when normally closed relays become activated, the circuit will open and cause the current to stop flowing.

Types of Electromechanical Relays

Electromechanical relays can be broken down into the following distinct categories: general purpose relays, machine control relays and reed relays.

General Purpose Relays

General purpose relays are electromechanical switches that typically function via a  magnetic coil. Using an AC or DC current, general purpose relays often run at voltages such as 12V, 24V, 48V, 120V and 230V. Additionally, they can command currents ranging from 2A-30A. These relays are sought after due to them having a multitude of switch configurations and being cost-effective.

Machine Control Relays

Like general purpose relays, machine control relays are operated by a magnetic coil. Typically used to control starters and other industrial elements, these relays are robust. While this gives them greater durability, it also means that they are less economical than general purpose relays. However, with additional accessories and functionality, they have an advantage over general purpose relays.

Reed Relays

Reed relays consist of two reeds, which can open or close when controlled by an electromagnet. These small relays can operate up to eight reed switches, which are typically found inside of the electromagnetic coil. When the magnetic force is removed, the reeds return to their initial open position. Since the reeds are only a short distance apart from each other, reed relays work rather quickly. There are many benefits of using a reed relay, as their hermetic seal prevents the passage of contaminants. Additionally, this seal enables reed relays to have dependable switching.

There are many things to consider when choosing a relay for a project. Lifespan, operating environment, mechanical loads, size, and number and type of contacts are all important factors in choosing the right relay.

Pros and Cons of Electromechanical Relays

While electromechanical relays have a variety of uses, different applications require different automation devices, and electromechanical relays may not always be the best fit. To help you determine if an electromechanical relay will work for you, we have highlighted some of the advantages and disadvantages below.


  • Fast operation and reset
  • More definitive ON/OFF
  • Simple and most reliable


  • Suffers the effects of age
  • No directional features
  • Needs a large amount of input power to operate

How to Identify a Faulty Relay

Although relays are considered reliable mechanisms, they do have the capability of failing. Determining whether you have a faulty relay is simple and can be easily identified with the help of a multimeter. 

Here are a few tips on how to use your multimeter to test a relay:

  1. Remove the relay from the fuse box or vehicle.
  2. Determine where the input and output points of the circuit are located on the relay.
  3. Make sure your multimeter is set to ohm.
  4. Connect the leads of the multimeter across the entrance and exit pins to determine resistance. Ideally, you’ll see a reading between 50 to 120 ohm.
  5. If your multimeter has a reading of Open or Out of Range you may have a defective coil winding and the relay will need to be replaced.
  6. If the reading looks good, you’ll want to connect the leads in between the switch pins. You should see a reading of OL or Open.

MRO Electric and Supply has an extensive inventory of relays in stock.  Please email sales@mroelectric or call us at 800-691-8511 for a quote.

Most Popular Movie Robot in Every U.S. State

The Most Popular Movie Robot in Every U.S. State

From dystopian stories of service companion androids trying to annihilate the human race, to friendly misunderstood cyborgs, robot movies allow us to catch a glimpse of an unknown universe. What does it mean to be human? Are we replaceable?

Each film takes you on a deep dive into the best and worst parts of technology. But with the exciting journey of each robot film, which bot is most popular?


For this study, we analyzed Google Trends search volumes over the past 12 months for “The Greatest Movie Robots of All Time” in  January 2022. At MRO Electric, our goal was to determine which androids, cyborgs, AI, and bots are America’s favorite.

The Most Popular Movie Robot in the U.S.

Are your batteries charged? Because our results are calculated! Most states were split with their decision, with varying results. However, 6 states each agree R2-D2 and The Sentinels earned the number 1 spot for most beloved bot character. 5 states chose the Tin Man, making it second place, while Robby the Robot was picked by 3. Roy Batty, The Iron Giant, the Autobots, Mechagodzilla, and WALL-E tied for fourth.

The Most Popular Movie Robot Overall

Star Wars is filled with memorable iconic characters, but Second Generation Robotic Droid Series-2, also known as R2-D2, is the most lovable bot in the U.S. According to our research, 6 states think R2-D2 is a force to reckon with: Alabama, Massachusetts, New Mexico, Utah, Wisconsin, and Wyoming. There’s just something captivating about his playful whistles, beeps, round eyes, and cylindrical body. 

Tied with R2-D2 are The Sentinels, also referred to as a “squiddy” by the Human Resistance in The Matrix. Georgia, Maryland, Michigan, North Carolina, Ohio, and South Carolina have the patrolling killing machines stuck on their minds. The terrifying patrollers of the sewers and caverns beneath the planet’s destroyed surface. Unlike R2-D2’s sweet demeanor, these giant squid-like bots tend to intimidatingly fly in swarms like insects and are set on eradicating humankind on behalf of the Machines. 

“A heart is not judged by how much you love; but by how much you are loved by others.” The Wizard of Oz’s Tin Man, despite being without a heart, has captured the hearts of D.C., Idaho, Iowa, Missouri, and Tennessee. Not only did this sensitive bot meet Dorthy second on her journey following the yellow brick road, but also earned second place. Somewhere over a rainbow, his generous and compassionate spirit is still felt by many. 

From the classic Forbidden Planet, Robby the Robot has become one of the most popular bot icons in robot movie history—and 3 states agree. Arkansas, Kentucky, and Minnesota were enchanted by his charming gentleman manners, and maybe wouldn’t mind having their own Robby the Robot. Built by Dr. Morbius, Robby must obey the Law of Robotics: a bot may not injure a human, must obey human orders, and protect its own existence. 

6 bots tied for fourth: Lt. Commander Data, Roy Batty, The Iron Giant, Autobots, Mechagodzilla, and Disney Pixar’s WALL-E. 

Closing Thoughts

As you binge watch robot movies to see these loved characters in action, we’ll take care of your automation needs. Just like the Tin Man needed a new heart, at MRO Electric, we provide quality new parts with quality repairs—you won’t be hassled by an evil witch either. As an independent automation distributor, our specialty is to provide new surplus and remanufactured products and top-notch services. We took some service tips from Robby the Robot.

Get Paid $1,000 to Watch Space Movies!

Title image for space movie marathon job posting


We received and enjoyed reviewing over 1,100 submissions before making a tough decision on who should take up the mantle as couch potato/space explorer extraordinaire. We are thrilled to announce that we have selected the winner of our Get Paid to Watch Space Movies job posting: Katherine Fricks!

Katherine’s inquisitive nature and passion for space travel really shone through to us and her love of all things sci-fi runs deep. She explains it best herself:

I am the daughter of an aerospace engineer who grew up learning how to say the names of the constellations and how to identify them in the night sky before I was out of diapers. When we did industry reports in fourth grade, I chose to do mine on the aerospace Industry. I learned how to build a bottle rocket launcher in fifth grade for science fair project [and] I went to space camp in California and the space academy in Alabama. I have even taught astronomy as a professor in a Harry Potter RPG forum. 

Astronomy and an admiration for space is something that has been instilled in me since I was a very young girl, particularly because my [father] was also a HUGE Trekkie. “Space, the final frontier…to explore strange new worlds. To seek out new life and new civilizations. To boldly go where no man has gone before!” became a sort of motto for which I live by.

For me, the appeal of space travel is exploration, and I remember watching the lunar landing as a little girl and thinking how amazing [it] would be to step foot on another planet. In fact, Captain Kathryn Janeway was my role model from 5th-7th grade as a strong female scientist and explorer, and those were SO rare and what draws me to Emily Calandrelli today—Emily’s Wonderlab is something I love to watch with my two sons.

I suppose were I able to go into space, I would like to assist with research on the International Space Station for a bit. I don’t know that I would want to spend months or years in space, but at least a week doing some sort of research regarding biology or astrobiology.

Good luck circling the stars from home, Katherine!

Update: Katherine zipped through the cinematic exploration of all 12 space stories and had a chance to tell us about it back here on Earth. Her analysis was deep and fascinating, cementing her as the right choice for her project. Here is what she had to say about stepping into the shoes of the main characters in The Right Stuff

The era depicted in the film is one in which astronauts and spaceflight are seen as flexes of power, where the humans riding in these capsules are seen more as tools and symbols rather than as people in a power struggle between countries. The men have to fight back against certain metaphorical manhandlings and there is immense pressure to be the perfect poster boys for the American space program. There is more concern with ‘beating the Russians’ and doing so quickly even if it means cutting a few corners. Of course, none of the men were forced to go and knew the risks associated with their particular flights and elected to go regardless, as is the case with Glenn.

I am not sure that I would be as trusting and willing in such a situation. However, Glenn’s ‘space fireflies’ (which we now know were illuminated frost flakes) was so beautifully captured in the film and seeing that view along with Earth in the background from space with its sunrises and sunsets is a sight I would very much like to see.


Think you got what it takes? Could you suit up, lock into the cockpit of a space shuttle, give your friends and family one last wave, and blast off into heavens unknown? No? Well, it’s not for everybody. At least not the everyday person. However, some of planet Earth’s ultra-rich billionaires are flaunting planet-sized wads of cash to take their shot at the stars.

Jeff Bezos and Richard Branson have now both gone to space. Even William Shatner (yes, Captain Kirk) did it. Maybe you have the stomach for it, too; maybe not. Either way, you probably won’t get the chance any time soon unless you’re a billionaire. But you can do the next best thing—and get paid for it in the process!

At MRO Electric, we’re fascinated by the automation processes and systems that make these incredible interstellar flights possible. That’s why we’re looking for someone to watch 12 space movies. And we’re offering $1,000 to the chosen applicant.

Who We’re Looking For

We’re looking for a seasoned space movie voyager willing to trade a cockpit for the couch, a space suit for pajamas, and dehydrated rations for popcorn and a Big Gulp. In addition to watching space movies, you’ll be asked to take notes and track specific details in each of the movies. 

The ideal applicant will have:

  • Overall enthusiasm for space travel
  • Love for movies, especially the science fiction genre
  • Strong attention to detail
  • The ability and availability to watch 12 movies within one month’s time

Additionally, applicants must be 18 years or older and a U.S. citizen or permanent resident to apply.

What You’ll Need to Do

We’ve narrowed down the vast galaxy of classic space movies to a list of 12 that you’ll be asked to watch over 1 month’s time.

  • 2001: A Space Odyssey
  • The Martian
  • Interstellar
  • Moon
  • Proxima
  • Passengers
  • Hidden Figures
  • Apollo 13
  • First Man
  • The Right Stuff
  • Gravity
  • October Sky

We will provide you with a worksheet to complete for each movie as you watch. All movies will need to be watched and all worksheets will need to be completed by December 23, 2021. We will incorporate your responses from the worksheet into a blog article to be published on the MRO Electric website.

How to Enter

To enter the contest, contestants MUST FOLLOW THE LINK BELOW to the entry form, where you’ll be asked to tell us why you’re the perfect person for this mission. Applicants’ level of enthusiasm for space travel, movies, and science fiction will be a strong factor for consideration, so provide what you need to demonstrate how and why you love these subjects the most.

The deadline for contest entries is Friday, November 26, 2021. Contestants will need to submit their applications by that date in order to be considered.

We will select and notify the winner by December 2, 2021.

What You’ll Get

The winner will receive a $1,000 payment upon satisfactory completion of watching all aforementioned movies and submitting notes taken throughout.

Contest Terms and Conditions

  1. The promoter of this competition is MRO Electric whose principal office is located at 1652 Old Apex Road Cary, NC 27513.
  2. Employees of MRO Electric or their family members or anyone else connected in any way with the competition or helping to set up the competition shall not be permitted to enter the competition.
  3. Persons must be at least 18 years old, or otherwise have reached the age of majority under the laws of the state where they reside, in order to participate.
  4. Only residents of the United States are eligible to participate.
  6. There is NO ENTRY FEE AND NO PURCHASE NECESSARY TO ENTER THIS COMPETITION. Any purchase or consideration otherwise given by entrants will not improve one’s chances of winning.
  7. The route to entry for the competition and details of how to enter are available via www.mroelectric.com. Individuals may enter to win by clicking on the participation link on MRO Electric’s website. Upon clicking the participation link, entrants will be asked to provide their name and contact information so that MRO Electric can notify the winner of the results.
  8. The closing date for entry will be November 26, 2021. After this date, no further entries to the competition will be permitted.
  9. Only one winner will be selected from the entire pool of eligible entries. The selection process will be at the discretion of MRO Electric. The winner will be required to complete certain tasks designated by MRO Electric. If the winner does not follow through with the tasks required of them, they will not receive the prize of $1,000.
  10. The winner will be notified by email and/or letter within 15 business days of the closing date. If the winner cannot be contacted or does not claim the prize within 2 days of notification, we reserve the right to withdraw the prize from the winner and pick a replacement winner.
  11. MRO Electric will notify the winner when and where the prize can be collected.
  12. The winner agrees to the use of his/her name, image, and video in any publicity material. Any personal data relating to the winner or any other entrants will be used solely in accordance with current federal and state data protection legislation and will not be disclosed to a third party without the entrant’s prior consent.
  13. The winner’s name will be available 28 days after the closing date by sending a stamped addressed envelope to the following address:
    • 1652 Old Apex Road Cary, NC 27513
  14. MRO Electric’s decision in respect of all matters to do with the competition will be final and no correspondence will be entered into.

Testing Your Fanuc Servo Motor

Here are some basic principles for troubleshooting a FANUC motor circuits with meter or megohm meter. This procedure will show you how to test for shorts in windings, cables, or opens. Before starting to test, make sure to turn all all the power sources to the machine and then disconnect the 3-phase motor lines from the drive end. Visually confirm that there are no problems with the cable and then begin testing.

Testing for a short to ground:

Using an Ohm meter:

  • Disconnect all power and amplifiers from machine. Check all three wires at T1, T2, and T3 (all three phases) to the ground wire. The readings for this should be infinite, and if it is zero or reads any continuity then there is a problem with the motor or the cable. For this disconnect the cable and check each separately. Be sure to make sure leads on both ends are not touching anything, including the other leads. Most servo motor shorts can be ready with a regular quality  meter going to at least 10 megaohms.

Using a Megohm meter:

  • Disconnect all power from machine. Check all three wires at T1, T2, and T3 (all three phases) to the ground wire. Reading should be between 600-2000 Megohms. Most shorts will be below 20 Megohms. Be careful not to touch the leads or the wires to anything when taking the reading because it can give a false reading. There should be about 1000 Ohms of resistance for each volt of incoming power, but this is not a standard rule. If it is 230meg to 600meg there may be deterioration in the cable.

Testing for Open or Short in the windings:

Using an Ohm meter:

  • Disconnect all power from the machine. Put meter on ohms and test T1 to T2, T2 to T3, and T1 to T3. The range should be between 0.3 and 2.0 ohms, with most being at about 0.8 ohms. If it is zero there is a short between the two phases. If it is an open the reading will be infinite or well above 2,000 ohms.

Cable and plug notes:

  • Often times the connector on the cable to the motor will get coolant in it. You can dry it out an retest, if it is still bad the inserts will get burn marks in them and cause a slight short, so they need to be replaced. If it is a DC motor, check the brushes. There should be 3-4 round caps to remove around the motor. Under these there is a spring with a square block (brush). Check to see how much is left, they may need to be replaced.


MRO Electric has a large stock of FANUC motors available. If you would like a replacement or spare, or if you have any questions, please call 800-691-8511 or email sales@mroelectric.com. To check out other posts, please visit our blog page.