Problems with Buying Used Industrial Automation Control Equipment

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The Potential Problems with Buying Used Industrial Automation and Control Equipment

There are many different piece of machinery involved in any type of manufacturing. Most of these complex systems are not simply purchased fully assembled. Rather, they require a wide array of different parts, working in concert, in order to function properly. Many of these different parts fall into the category of industrial automation and control equipment. These pieces work to make industrial machinery operate smoothly and safely with less chance of human error. This specialised equipment is available from both industrial wholesalers and online on eBay.

In order to effectively shop for a purchase industrial automation and control equipment, it is necessary to have a thorough understanding of the types of equipment that is available. Although it may save money in the short term, there are some potential problems when it comes to purchasing used industrial automation and control equipment, including reduced precision, a shorter period of usability, and compatibility issues.

Types of Industrial Automation and Control Equipment

The first thing to consider when purchasing industrial automation and control equipment, whether it is new or used, is what type of equipment is necessary for the situation. The category of industrial automation is one that is quite broad and so there are a number of different tools and items that fall under that umbrella. In addition, some types of automation or control equipment are more suitable for purchase as used.

Programmable Logic Controller

A programmable logic controller , which may also be referred to using the acronym PCL, is a type of digital computer that is used specifically to control the operations of large machinery. It is able to do this by maintaining control over the electromechanical processes of these machines. Although the term PCL is a registered trademark of Allen-Bradley, there are other companies who manufacture similar controls.

Programmable Logic Controller Features

Programmable logic controllers are much different than the standard conception of a computer. They are designed to receive many different types of inputs and also to produce many different outputs, such as running motors or operating hydraulic cylinders.

Temperature Controller

Another important application of industrial automation is the temperature controller . These devices, as the name suggests, are designed to regulate the temperature of a specific area, machine, or item. For instance, a tropical aquarium needs to be maintained at a certain temperature in order for the fish to thrive and so a temperature controller should be used to maintain the temperature of the water. A typical household thermostat is also an example of a temperature controller, although not in the industrial sense.


A sensor may be a built-in part of another type of industrial automation equipment, or it may be a separate entity. In the case of a temperature controller, for instance, a built-in sensor is necessary to convey the existing temperature to the controller so that it can make necessary adjustments, whether that means turning on the heater or turning down the air conditioner. A sensor is not necessarily for detecting temperatures and can also be used to detect moisture, movement, or other ambient conditions depending on the type of sensor.


A relay is another type of industrial automation equipment that can be described simply as an electrically operated switch. Relays are a very basic type of electrical equipment and were actually first used to control long distance telegraph circuits. More so than some other types of industrial automation equipment, relays are easily replaced and fairly inexpensive precisely because they are so simple.

Summary Chart

This is not an exhaustive chart, and there are other common types of industrial automation and control equipment. The following table summarizes the types that have been discussed as well as some others.

Type of Equipment


Popular Brands

Programmable Logic Controller

Control the mechanical processes of machinery


Temperature Controller

Regulate temperatures in controlled environments



Sense changes in temperature, moisture, or other environmental factors



Act as a switch in an electrical circuit



Connects electric motors to a power supply



Changes direct current to alternating current


The type of industrial automation and control equipment is largely dependent on the type of project one is undertaking. It is also important to keep in mind that many projects require multiple pieces of equipment in order to be fully functional.

Potential Problems with Used Industrial Automation Equipment

Because industrial automation and control equipment is highly specialised, it can also be quite costly. For this reason, it may be tempting to purchase this type of equipment used since that can lead to significant savings. However, there are some problems that may arise if this equipment is purchased used rather than brand new. Anyone considering making a purchase of used automation and control equipment should keep these things in mind.


Naturally, some types of industrial automation require extreme precision. For example, a particular temperature control may need to be accurate to the exact degree in order to keep a machine running smoothly. A piece of measuring equipment like a used temperature controller or a used sensor is less likely to be extremely precise than a new temperature controller or sensor. This is because this type of equipment is generally carefully tuned when it is first manufactured, so this is when it is most precise. Wear and tear can lead to a less precise piece of equipment, which can certainly be a problem.


It goes without saying that a piece of used industrial automation equipment is older than a piece of new equipment, and this can potentially lead to problems. The longer that a piece of equipment has already been used, the shorter its useable life has become. For example, purchasing a sensor that has a typical life of five years, which has already been used for three years, now only has a life of two years. While this discrepancy may be reflected in the price, it is also important to consider the time and money lost in the form of productivity when that same sensor needs to be replaced again in two years.


Buying used industrial automation and control equipment can also lead to compatibility issues. When purchasing new equipment, it is usually very easy to figure out exactly what type of machines are compatible with whatever is being purchased, particularly if it is in its original packaging. On the other hand, used equipment rarely comes with the same type of documentation, and therefore, it may be much more difficult to determine compatibility. It is a good idea to look for used equipment that still has its original documentation or packaging for this reason.

Industrial Automation Equipment Brands

For those that do decide to purchase used industrial automation equipment as opposed to new equipment, it is a good idea to consider purchasing from a reputable brand. There are a few trusted brands that make this type of equipment, including Siemens, Allen Bradley, and Omron.


Siemens is a German conglomerate that has been in business in one form or another since 1847. The company specialises in engineering- and electronics-related products and services, which includes a wide range of reliable industrial automation and control equipment. Their equipment is very widely available and encompasses virtually every type of automation and control. Siemens equipment is particularly popular in Europe, where the company is based.


Allen-Bradley, which is also known by the abbreviation A-B is another brand that is quite popular. It is owned by parent company Rockwell Automation and specialises in automation equipment. As previously mentioned, Allen-Bradley owns the trademark for the name Programmable Logic Controller and therefore Allen-Bradley Programmable Logic Controllers are quite popular. However, they also offer temperature controllers and other types of automation equipment and have since the early 1900s.


As opposed to the other two companies, both of which have their basis in the West, Omron was established in Japan in 1933. This is the reason that Omron automation and control equipment has taken a larger market share in Japan and other parts of Asia, while Siemens and Allen-Bradley remain most popular in Europe and North America. Omron also specialises in automation equipment although they also make medical equipment and even automated teller machines.


Manufacturing and mechanical or electrical systems may not be as widely known or studied as they once were, making way for computers and complete automation. However, there are still many different fields that rely on complex machinery and the people that know how to operate and repair them. This includes those people that know when and how to replace industrial automation and control equipment like relays, sensors, and temperature controllers. It is much easier to replace these types of parts today because they are so widely available. However, it is still important to know exactly what type of equipment is needed and in what condition.

It can be tempting to look for steep discounts on used items, but it is important to consider the fact that these do not necessarily mean savings in the long run. Still, for some equipment, it is certainly possible to find used versions that work well at a lower price, just be sure to keep those potential problems that may arise in mind.

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