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.
Recently I read an article in Machine Design called “When Flexible Cables Doesn’t Flex for Long” by Leland Teschler which talks about different aspects of flexible cable terms, causes of breakage and testing.
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.
From conversations with many of our customers, I have found that there are two key problems encountered when working with tool change-outs:
- Tool Identification: “How do I know I have the right tool in there for the right job at the right time?”
- Cables & Connectors: “How do I remember every time to disconnect them before the tooling is removed? We spend thousands each year repairing dies with the cordsets torn out.”
Continue reading “Implement Hassle Free Tool Changes”
In the design of automation equipment everyone is looking for an edge. How can I make parts faster or easier or safer? I’m sure you don’t encounter the need for 360 degree rotation everyday; but when you do, it can become a pain to maintain sensor and actuator information or even a network connection.
There are two different ways to maintain your connection in a rotation application:
Continue reading “How to Maintain Your Rotating Connection”
Since my first post on NFPA79 in relation to sensor cables was published, there have been more and more customers asking me for a statement of compliance. So after much review, we decided to ask the professionals. As a member of the NFPA you can call and talk to a document specialist to help you clarify the wording and how it applies to your exact situation.
During my conversations with them, I learned that a new revision of NFPA79 that will be released in 2011. This version I hope will help clarify the concerns people have with the original wording “188.8.131.52 Single conductor or multi-conductor Type AWM shall not be permitted.” Most, if not all, sensor cables are built-in the Type AWM.
Continue reading “NFPA 79 for AWM Cables in 2011”
Let’s face it; an installed base, a trained maintenance crew, and an established set of procedures all make it really difficult to try to implement any new technologies in a running manufacturing facility. The idea of an industrial network providing detailed data about your processes and improving productivity sounds interesting and valuable, but where do you begin? Retrofitting everything with the newest technology isn’t an option in today’s economy, the capital investment is just too great. But there is hope! And with small steps, time and training, any plant can move forward into the ethernet realm and beyond.
Continue reading “3 Steps to Evolve to Ethernet Networked I/O”
Over the last year I have been discussing IP rated products with people in various positions in the manufacturing world and I have encountered some false assumptions about IP67 protection. I want to quickly go over what an IP67 test actually is and then go into the assumptions I’ve seen.
Continue reading “The Secret of IP67 Protection”
If you aren’t familiar with the NFPA, here is a brief summary from their website:
“The mission of the international nonprofit NFPA, established in 1896, is to reduce the worldwide burden of fire and other hazards on the quality of life by providing and advocating consensus codes and standards, research,training, and education.” http://www.nfpa.org/
Continue reading “Sensor Cables and the National Fire Protection Agency”