Grizzly G1028Z/G1029 - Manual (Page 18)

-16- G1028Z/G1029 Dust Collector
Since plastic hose is abundant, relatively inexpen-
sive, easily assembled and air tight, it is a very
popular material for conveying dust from wood-
working machines to the dust collector. We rec-
ommend using flexible hose (flex-hose) to con-
nect the woodworking machine to the dust collec-
tor. However, plastic flex-hose and plastic duct
are an insulator, and dust particles moving
against the walls of the plastic duct create a stat-
ic 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 con-
firm that the dust collector is continuously ground-
ed through the electrical circuit to the electric ser-
vice 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.
System Grounding
Always guard against
static electrical build up
by grounding all dust
collection lines.
There are also many kinds of pure plastic flexible
hose, such as non-perforated drainage type hose
and dryer vent hose. Drainage type hose, while
being economical, does not quite have the flexi-
bility required for dust collection. The inside of the
duct is also deeply corrugated and can increase
the static pressure loss by as much as 50% over
smooth wall duct. Dryer vent hose, while being
completely flexible, is non-resistant to abrasion
and has a tendency to collapse in a negative
pressure system.
If using flex-hose, you should choose one of the
many types that are designed specifically for the
movement of solid particles, i.e. dust, grains and
plastics. However, the cost of specifically
designed flexible duct can vary greatly. Grizzly
offers polyethylene hose which is well suited for
the removal of particulate matter, especially saw-
dust, since it is durable and completely flexible.
Polyethylene is also very economical and avail-
able in a wide variety of diameters and lengths for
most applications.
PLASTIC DUCT
The popularity of plastic duct is due to the fact that
it is an economical and readily available product.
It is also simple to assemble and easily sealed
against air loss. The primary disadvantage of
plastic duct for dust collection, whether black ABS
or white PVC and even rubber or polyethylene
flex-hose, is the inherent danger of static electri-
cal build-up.