Page 182 - Electromechanical Devices and Components Illustrated Sourcebook

144 Electromechanical Devices & Components Illustrated Sourcebook

Grounded Mount Tab
Ground Terminal
AC Receptacle Hook

Wire Nut
Bare Ground Wires
Conduit Connector
Conduit Pipe Clamp

Ground
Terminal
Junction To Ground
Box Rod

Figure 8-33 Grounding Conduit and Junction Boxes

Static Protection

When working with or servicing sensitive electronics, the Ground Clamp High-Voltage
slightest discharge may severely damage the sensitive cir- Insulating Handle
cuitry. Most service technicians wear a wrist ground during
these periods. The wrist ground, as shown in Figure 8-34, is
simple a brass rivet held against the wrist by a hook and loop
strap. The brass rivet is connected to an earth ground. Any Ground Wire
charge that may build up on the service technician is harm-
lessly shorted to ground. In this manner sensitive electronics
are protected from stray transients. Figure 8-35 Grounding Hook or “Jesus Stick”

Hook and
Loop Strap Ground Wire
Faraday Cage
Protecting delicate equipment from external transients is the
task of the faraday cage. A faraday cage is simply a conduc-
Brass Rivet tive enclosure that is grounded. Any transient that reaches the
cage is immediately conducted to ground. The equipment in
the cage is completely protected by the cage. Figure 8-36
Ground Lug
Figure 8-34 Wrist Ground

Grounding Hooks

Grounding hooks, or Jesus sticks as they are sometimes
called, are important safety devices when dealing with high- Metal Cover
voltage equipment. When you ask a technician why it’s called
a Jesus stick, he’ll respond, “When working with this equip- Equipment to
ment, it’s the only thing that keeps you from meeting Jesus.” be Protected
Figure 8-35 shows a typical grounding hook. The ground
clamp should be a semipermanent or permanent connection
so that it cannot be inadvertently pulled off and disconnected. Cover Screws
To assure that a conductor is at zero potential, the metal hook Metal Base
is looped over the wire and any existing charge will be shorted Pipe Clamp
to ground. These devices should be inspected regularly for Metal Conduit
Ground Wire
damage and dirt. If found to be in a poor state of repair, they
should be discarded. Figure 8-36 Faraday Cage