System Grounding

Since plastic hose is abundant, relatively inex- pensive, easily assembled, and airtight, it is a very popular material for conveying dust from woodworking machines to the dust collector. We recommend using flexible hose (flex-hose) to connect the woodworking machine to the dust collector. However, plastic piping, including plas- tic flex-hose, is an insulator, and dust particles moving against the walls of the pipe create a sta- tic electrical charge build-up. This charge will build until it discharges to ground. If a grounding medium is not available to prevent static electrical charge build-up, the electrical discharge will arc, similar to lightning. This electrical discharge may cause an explosion and subsequent fire inside the system.

To protect against static electrical charge build- up inside a non-conducting duct, a bare copper wire should be placed inside the duct along its length and grounded to the dust collector. Please ensure 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- ing wire inside the entire duct system and attach- ing 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 when two branch- es meet at a Y or T connection. Use wire nuts.

Ensure that the entire system is grounded. If using blast gates to direct air flow, the grounding wire must be jumped around the blast gate with- out interruption to the grounding system.

We also recommend wrapping the outside of all plastic ducts with bare copper wire to ground the outside of the system against static electricity 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 the dust collector frame with a ground screw. Ensure that each machine is continuously grounded to the ground- ing terminal in your electric service panel.

Figure 7.

G1032 Dust Collector

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