System Grounding - Grizzly G0671 Owner's Manual

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
a non-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.
g0671/g0672/g0673 dust Collector
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.
Copper
ground
Wire
figure 40. ground jumper wire when using
plastic blast gates and metal duct.
external ground
Wire
internal
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.
plastic
Blast
gate
Metal duct
ground screw
-33-