What is 4-20 ma?

This article will be geared towards the curious, I am not going to try to train you how to work with the subject materiel.
But you will be able to converse intelligently after reading this.

BASIC DEFINITION

4-20ma can be either an input or output from the perspective of a PLC, (Programmable Logic Controller)which was covered in an earlier article.
The PLC specialty cards necessary are referred to as Analog cards(both input and output types).

MA stands for milliamp, a measurement of current flow. 4-20 is the lower and upper limits of this defined scale.
One example is the use of this scale to order a motor to run at a specific speed, with 4ma representing stopped and 20ma representing full speed.

Continue reading “What is 4-20 ma?”

The Joy Of Victorious Troubleshooting

Usually In a manufacturing facility you will find several mechanics and only 1 or 2 electrical people at any given time.
This is because you are dealing with moving equipment, which breaks and wears out frequently.
For the electrical people there are plenty of preventative maintenance tasks and upgrades to do.

However sometimes the equipment refuses to work or does something erratic, and no one knows why. Continue reading “The Joy Of Victorious Troubleshooting”

About Motor troubleshooting and the use of Meggers…

This particular activity is potentially very dangerous because power needs to be applied and locked out frequently, so please follow proper lockout-tagout procedures!
Meggers are a must in the area of industrial electrical troubleshooting because they can help quickly identify some sources of malfunctions while eliminating other sources as the cause of the malfunction.
As an example, let’s say that a motor refuses to turn. The problem could be coming from let’s say 3 different directions. Continue reading “About Motor troubleshooting and the use of Meggers…”