Janet Czubek has experience and knowledge of the industrial automation industry with Balluff. With her product and industry knowledge, she is sharing her passion for automation with Automation Insights.
Everyone is looking for quick tricks of the trade. Sensor failure can prove to be costly in any environment. One of the easiest ways to avoid unnecessary downtime would be to add a mounting bracket plus prox mount to the machine to extend the life of a sensor.
What is a prox mount?
It has a quick release tube mounted into a tubular bracket to change out a sensor easily. The sensor is assembled into the prox mount tube and locked into place with a compression ring and metal nut. The prox mount and sensor assembly is then mounted and adjusted as with any tubular sensor, but the prox mount will remain in place on future sensor replacement tasks.
Mounting accessories are geared toward extending sensor performance in harsh industrial conditions involving chemical attack, debris accumulation, shock/vibration/impact, and high temperatures. The brackets act as protection, as well as mounting for the sensor to extend the life of the sensor. Adding a prox mount to it add another layer of protection as well as reducing down time due to the quick release to change a sensor.
Mounting brackets are a simple solution to decrease installation costs by screwing in the bracket on the machine. They are also prolonging sensor life expectancy by giving it an added layer of protection. Add in the prox mount for a faster option to reduce unplanned downtime with the quick release of the sensors. This helps increase the overall performance and utility of sensors.
Whether it’s through preventative maintenance or during planned machine downtime, reducing downtime is a common goal for manufacturers. Difficult environments create challenges for not just machines, but also the components like sensors or cables. Below are three tips to help protect these components and reduce your downtime.
Cables don’t last forever. However, they are important for operations and keeping them functional is vital. An easy way to help reduce downtime and save money is by implementing a “sacrificial cable” in unforgiving environments. A sacrificial cable is any cable less than two meters in length and placed in situations where there is high turnover of cables. This sacrificial cable does not have to be a specialty cable with a custom jacket. It can be a simple 1 meter PVC cable that will get changed out often. The idea is to place a sacrificial cable in a problematic area and connect it to a longer length cable, or a home-run cable. The benefits of this method include: less downtime for maintenance when changing out failures, reduced expenses since shorter cables are less expensive, and there is less travel for the cable around a cell.
A second way to help reduce downtime is consider your application conditions up front. We discussed some of the application conditions to consider in a previous blog post, but how can we address these challenges? Not only is it important to choose the correct sensor for the environment, but remember, cables don’t last forever. Choosing the appropriate cable is also key to reducing downtime. Welding environments demand a cable that weld beads will not stick to and fuse the cable to the sensor. There are a variety of jacket types like silicone, silicone tube, or PTFE that prevent weld debris from accumulating on the cable. I’ve also seen applications where there is a lot of debris cutting through cables. In this case, a stainless steel braid cable would be a better solution than a traditional cable. Fitting the right protection to the right application is crucial..
A third tip to help reduce your machine downtime is to simply add protection to your existing components. Adding protection, whether it is a protective bracket or a silicone product, will help keep components running longer. This type of protection can be added before or after the cell is operational. One example of sensor protection is adding a ceramic cap to protect the face of a sensor. You can also protect the connection by adding tubing to the cable out version of the sensor to shield it from debris. Mounting sensors in a robust bracket helps protect the sensor from being hit, or having debris cover the sensor. There are different degrees of changes that help prolong operations.
Metalforming expert, Dave Bird, explains some of these solutions in the video below. To learn more you can also visit our website at www.balluff.us.
When working in harsh environments and in heavy duty applications like welding, it is important to take a multi-angle approach to designing the application. When you are working with existing sensor installations, it is important to consider all the reasons for the sensor’s failure before determining a winning solution. An important step in any application is to protect the connection between the controller and the sensor. In a welding environment, whether the sensor cable fails from weld slag buildup or from physical damage from contact with a part, the cable can be the key to a successful weld-sensing application.
That being said, the number of options available to protect the connection can be overwhelming and at times even confusing. For example, silicone cables vs silicone tube cables. Silicone cables have a jacket that is made out of silicone material over the conductors. This usually allows for a smaller diameter and more variety with the cordsets i.e. length and connector types. On the other hand, a silicone tube cable is a standard sensor cable with a silicone pulled over the cable then over-molded. The silicone tube is a second jacket and the air is a good insulator, prolonging the life of the sensor cable.
Another important consideration is how to even connect your sensor. One option is to install a sensor with a connector. This allows for a quick disconnect from the cable. In this case, it may be better to use a right angle connector, so the bend radius of the cable is not hanging loose. A second option is to install a sensor with cable out. This can have flying leads or a connector added to the end. At times, when there is not enough room to add a cordset, the cable out gives extra space.
In industrial automation we put our products through a lot. Extreme temperatures, harsh environments, and the demands of high performance can put a strain on the components of any machine. This led me to wonder, if our products could talk, what would they say?
Cordset: Cables have certain limpness which makes installing the cordset in automation easier to fit in tight spaces. Most cable installers prefer to have the least amount of slack in cable to prevent the cable being snagged or pulled during operations. Cables need to have a bend radius to prevent kinking of the conductors and a continuous flow of power. The bend radius is “the smallest radius of curvature into which a material can be bent without damage” (McGraw-Hill Dictionary of Architecture and Construction). Typically in a fixed (stationary) application, an unshielded sensor cable has a minimum bending radius of 8 times the outer diameter of the cable.
Power Supply: Everyone wants a friend. When a load is too much for one power supply, adding another power supply helps increase the voltage or current output. “The simplest method to create higher current is to connect the power supplies in parallel and leave only one supply in constant voltage mode. Some power supplies are equipped with analog control signals that allow auto-parallel or auto-tracking, a more elegant way to control multiple power supplies. Auto-parallel supplies can be controlled with a single master supply; a second advantage is that all of the master power supplies features can be used.” (Keysight Technologies) By stringing together power supplies, it allows more voltage or current but also keeps operations up and running.
There are many different types of cable jackets and each jacket works well in a specific application. The three main sensor cable jackets are PVC (Polyvinyl Chloride), PUR (polyurethane) and TPE (thermoplastic elastomer). Each jacket type has different benefits like washdown, abrasion resistant or high flexing applications. Finding the correct jacket type for your application can extend the life of the cable.
PVC is a general purpose cable and is widely available. It is a common cable, and typically has the best price point. PVC has a high moisture resistance, which makes it a good choice for wash-down applications.
PUR is found mostly in Asia and Europe. This cable jacket type has good resistance against abrasion, oil and ozone. PUR is known for being Halogen free, not containing: chlorine, iodine, fluorine, bromine or astatine. This jacket type does have limited temperature range compared to the other jacket types, -40…80⁰C.
TPE is flexible, recyclable and has excellent cold temperature characteristics, -50…125⁰C. This cable is resistant against aging in the sunlight, UV and ozone. TPE has a high-flex rating, typically 10 million.
The table below details the resistance to different conditions. Note that these relative ratings are based on average performance. Special selective compounding of the jacket can improve performance.
Choosing the right jacket type can help reduce failures in the field, reducing downtime and costs. Please visit www.balluff.us to see Balluff’s offering of sensor cables in PVC, PUR and TPE.
The article touches on different lingo between flexible, high-flex and high-flex-life. Flexible and high-flex mean the same thing. Google’s definition of flexible is the capability of bending easily without breaking. High-flex-life is described by Northwire as a cable designed to survive 10 million to 20 million flexing cycles. Those are just the common terms used to describe flexing of a cable, but there are manufacturers that use their own flexing name to describe their cables.
Teschler also describes the feel of a cable, whether the cable bends easily or not, based on different degrees of limpness or stiffness. “All in all, cable makers say the stiffness or limpness of the cable has nothing to do with its flex life.” The article goes on to describe a limp cable as a jacket that is made from soft materials, or finely stranded conductors, that allow the cable to move easily but is not meant to be used in applications with repeated flexing.
The last part of the article mentions how cables are tested for flexing. There is not a standard in the industry so different manufacturers can use differernt tests. The 3 most common tests are twist and flex test, tick-tock cable test, and UL test setup. Teschler pointed out the main focus for UL and CSA is to test for fire safety and UL test the cables for runs of 15,000 cycles.
Overall, I really enjoyed the article and highly suggest giving it a read to understand more about raw cable and testing requirements.
To see Balluff’s offering of UL listed cables click here.
Environments with debris and caustic agents, wear down equipment exponentially. When a cell goes down, every minute counts to get production up and running. An accessory like a cordset is important for operations, and can frustrate technicians when it fails. Cordsets do not last forever in this environment and to help save money, time and work, we came up with the concept of a “sacrificial cable.” The basic idea is to install a double-ended cable under 2 meters to help in situations where cables are placed in surroundings which will destroy the cable. A sacrificial cable’s main function is to save time reducing cable replacement downtime and money.
Sacrifice Cordset Solution: Used in extremely rugged applications to reduce cordset replacement downtime
A sacrificial cable does not have to be a specialty cable with a custom jacket; it could just be a 1 meter PVC cable that will get changed out often. The idea is that by placing a sacrificial cable in a problematic area and connecting it to a longer length cable this will allow maintenance to have a shorter down time when changing out failures less. This is accomplished with travel around the cell following a cable run and less maintenance expense in labor.
In a previous post, I talked about receptacles for automation equipment. But there are many different types of mounting when it comes to receptacles. When picking a mounting type, it is based on preference. Each type of mounting has its good points. Depending on what else is inside the cabinet, might sway which mounting is preferred.
A popular mounting is front mounting. Front mounting comes into the panel from the outside of the control cabinet and is secured with lock (jamming) nut on the inside of the cabinet and sealed with an o-ring on the outside of the cabinet (figure to the right). The o-ring with the lock nut gives the receptacle a tight seal to keep out dust and moisture. It is one of the easier receptacles to replace since it is installed from the outside of the cabinet.
Another mounting type is back mounting. With a back mounting, the threads are on the connector part of the receptacle. Back mounting is the opposite of the front mounting with the o –ring and jamming nut on the outside of the cabinet. A back mounting receptacle takes some preplanning. The receptacle should go into the control cabinet first to make sure there is room for the other components in the cabinet like a power source, PLC or terminals. If the receptacle needs replaced, then it might require some of the components in the cabinet to be removed to have enough room to remove the receptacle.
From The Free dictionary by Farlex, a receptacle is defined as “A fitting connected to a power supply and equipped to receive a plug.” I like this definition it describes both halves of the receptacle. In the automotive industry, the back half of a receptacle has threading on the nut with leads that could possibly connect a power supply. The front half describes which kind of cordset is needed. Typically, receptacles are used in a control cabinet, where there is easy access and out of the movement of machinery. Inside a control cabinet is a power source and/or programmable logic controller (PLC) which a receptacle would be wired to in the configuration of the controller. Receptacles used on a control box normally have a tight seal to keep out moisture and dust.
When looking at a receptacle there are two ends with different kinds of threading. In the front of the receptacle has a connection for a cable to connect to the outside environment, cells, and machinery, to the control box. The different cables could have diameter widths of M8, M12, 7/8”, 1” and more. From the picture, we see the front side of the receptacle calls for the M12x1 which would use a M12 cable. The first number is always the diameter of the outer threads. The other end of the receptacle, ½”-14NPT, where the leads come out, has another diameter referred as to the mounting type. There are many different kinds of mounting: Metric, PG, NPT, front mount, back mount, panel mount, etc. The two mounts types being explained here are Metric and NPT.
In today’s industrial market, Ethernet cable is in high demand. With words like Ethernet, Ethernet/IP, solid, and stranded, making a decision from the different types of cable can be difficult.
I want to make it easy for you to pick the right cable to go with the network of your choosing. As a network, Ethernet is easy to install and it is easy to connect to other networks – you can probably even have Ethernet network devices connect to your current network.
So, let’s start with the basics…First, what is the difference between Ethernet and Ethernet/IP? They both have teal jackets (hence the title – The “Spring Line”) due to the industrial Ethernet standards in North America. So, the difference between the two is in the application. Ethernet is a good networking cable that transmits data like an internet cable. Ethernet/IP transmits data and also has an industrial protocol application. The Industrial Protocol (IP) allows you to transmit more data if you have a lot devices connected to each other or a lot of machines moving at once. Ethernet/IP resists against UV rays, vibrations, heat, dust, oil, chemical, and other environmental conditions.
Next, there are two kinds of Ethernet IP cables: Solid and Stranded. Solid is great for new applications that require high-speed Ethernet. The solid cables can transmit and receive across long distances and have a higher data rate compared to stranded. The downside is that solid cables can break, and do not bend or flex well. Stranded is a better cable if you have to bend, twist, or flex the cable. It’s also better if you have to run short distances. Stranded is made up of smaller gauge wires stranded together which allows the cable to be flexible and helps protect the cable. They move with the machine and will not break as easily as solid cables.
To recap, remember the four short bullet points below when choosing your next cable:
Ethernet – transmits data
Ethernet/IP – transmits data to many machines/devices