Every electrostatic paint line requires grounding. As each substrate enters the paint booth the question is always, "Is it grounded?" At this point you have cleaned the carrier, connected grounding straps (if necessary), and may have even coated the substrate with conductive material so you've done your job and your paint line will produce great results. Or will it? How do you know whether or not your paint line is providing a solid ground? How do you know it is really, safe to paint?
There are tools available to help identify solid grounding connections in paint lines. Some paint managers choose to use a multi-meter to read paint line resistance while others spend a great deal of time and money on an automated solution. There are, however, easy to use "Go/No-Go" tools ready available. One such system is the Ground Identification System from Mueller Electric. It is a programmable system which operates in a "Go/No-Go" environment. The system works by measuring the resistance between two connection points (Alligator Clips), and comparing that measurement to a programmed reference point. In this model (1.0):
- If the system is not connected, the indicator light will be blue.
- If the resistance is between 5K Ohms and the prgrammed reference point, then the indicator light will be red (indicating a bad ground). In this case there is also a switchable audio alarm that can be turned on.
- If the resistance is below the programmed reference point, then the indicator light will be green (indicating a good ground).
The unit must be connected to a 120 V. outlet and a good earth ground. This unit (1.0) will be shipped with two marked resisitors that can be used to prove the system is working correctly. The 100 Ohm resister will produce a "bad" ground signal and the 22 Ohm resister will prodcue a "good" ground signal. The resistors themselves can be verified with a multi-meter.
There are three different versions of the Ground Identification System.
The 1.0 which includes two large clips and is perfect for painting large objects.
The 1.5 which operates on a singular Alligator clip with an indicator on the clip.
The 3.5 which is a probe tip indicator which is perfect in identfying spot checks across the substrate or carrier.