Powder coating equipment grounding instructions

Grounding that is the protection to people and powder coating equipment from voltage.

The grounding process is the connection of a special device (grounding device or charger) to any point in an electrical installation or electrical network.

There are 2 types of grounding:

• natural;
• artificial.

Structures that are constantly in the ground (pipes, poles) are considered to be naturally grounded.

Artificial grounding is the purposeful connection of a grounding device to any point in the equipment.

In this article we will discuss the rules of artificial grounding for powder painting equipment.

The equipment grounding resistance must be less than 1 MΩ. By observing this condition, you can be sure of the equipment service time.

Grounding the spraying chamber

To ground the spraying chamber, a wire is required with technical characteristics corresponding to the project. The wire is directly connected to the distribution ground bus, which is directly connected to the ground rods.

The grounding line of the powder paint chamber: on the segment, starting from the mark of 5 meters to the entrance of the camera, and ending at the mark of 5 meters from the outlet of the camera, every 2.5 meters, a ground wire of 4 mm2 is laid along the conveyor.

In the absence of such a wire, the painting equipment should not be put into operation.

Grounding of powder coating equipment and other equipment

There must be a ground connection between all powder coating equipment: control panel cabinet, spraying chamber, spray gun, cyclone, etc.

In the process of connecting equipment to the installation, grounding must be carried out by a separate wire from the grounding bar to each equipment and device. The equipment should be grounded with a 4mm2 wire in a facility with an automatic painting line. 

Grounding the paint area

All equipment and parts located in the painting area within a radius of 5m2 must be grounded separately.

Floor conductivity

The floor in the paint shop must have good conductivity. A concrete floor is considered one of the best measures in terms of conductivity.

Suspension conductivity

Often paint is applied to the suspension that is the paint which breaks the conductivity. 

Therefore, the suspension must be burned frequently or replaced without fail. Otherwise the productivity of the spray gun decreases and the quality of the painting decreases.

Choosing material 

When choosing grounding materials, it is necessary to understand their electrochemical corrosion. Take care about the characteristics of the material and the soil of the installed place. Otherwise, different materials will interact and a phenomenon known as “battery” may occur. This phenomenon involves the flow of electrons from a high voltage metal to a low voltage metal. A metal that has lost electrons is depleted over time. 

That is why metals’ lifetime cycle gets shorter. To prevent this, the voltage should be:

• outdoors below 0.25 Volts,
• in an enclosed space below 0.50 Volts.

The values ​​corresponding to the Calomel electrode is 25°C in the seawater and shown in the table below.

Aluminum voltage drop: -0.75 V / m

Tin voltage value drop: -0.48V / m

Copper voltage drop: -0.18V / m

Metal stress values