System Grounding

Since plastic hose is abundant, relatively inex- pensive, easily assembled and air tight, it is a very popular material for conveying dust from woodworking machines to the dust collector. We recommend using flexible hose (flex-hose) to con- nect the woodworking machine to the dust collec- tion system. However, plastic flex-hose and plastic duct are insulators, and dust particles moving against the walls of the plastic duct create static electrical build up. This charge will build until it discharges to a ground. If a grounding medium is not available to prevent static electrical build up, the electrical charge will arc to the nearest grounded source. This electrical discharge may cause an explosion and subsequent fire inside the system.

To protect against static electrical build up inside

anon-conducting duct, a bare copper wire should be placed inside the duct along its length and grounded to the dust collector. You must also confirm that the dust collector is continuously grounded through the electrical circuit to the elec- tric service panel.

If you connect the dust collector to more than one machine by way of a non-conducting branching duct system and blast gates, the system must still be grounded as mentioned above. We recom- mend inserting a continuous bare copper ground wire inside the entire duct system and attaching the wire to each grounded woodworking machine and dust collector.

Be sure that you extend the bare copper wire down all branches of the system. Do not forget to connect the wires to each other with wire nuts when two branches meet at a “Y” or “T” connec- tion.

Always guard against static electrical build up by grounding all dust collection lines.

Ensure that the entire system is grounded. If using plastic blast gates to direct air flow, the grounding wire must be jumped (Figure 40) around the blast gate without interruption to the grounding system.

		Plastic
		Blast
		Gate
	Copper
	Ground	Metal Duct
	Wire	Metal Duct
	Wire

Figure 40. Ground jumper wire when using

plastic blast gates and metal duct.

	External Ground
	Wire
	Internal	Ground Screw
	Ground	Ground Screw
	Ground
	Wire
	Flex-Hose

Figure 41. Flex-hose grounded to machine.

We also recommend wrapping the outside of all plastic ducts with bare copper wire to ground the outside of the system against static electrical build up. Wire connections at Y’s and T’s should be made with wire nuts.

Attach the bare ground wire to each stationary woodworking machine and attach to the dust col- lector frame with a ground screw, as shown in Figure 41. Ensure that each machine is continu- ously grounded to the grounding terminal in your electric service panel.

G0671/G0672/G0673 Dust Collector

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