ERICO Practical Guide to Electrical Grounding - Manual (Page 104)

Practical Guide to Electrical Grounding
STATIC GROUNDING
Static electricity is a major cause of fires and explosions
where flammable powders and liquids are stored and
handled. The hazard of electrostatic spark ignition of a
flammable vapor can be minimized by taking actions to
limit the accumulation of electrostatic charges to safe
values. Of primary importance is the proper bonding and
grounding of equipment and containers. In addition, charge
accumulation must be limited, in many instances, by
controlling the rate of charge generation and/or the rate of
charge dissipation. Occasionally, such methods cannot be
applied and the use of an inert gas in vapor spaces must
be used.
Sources of Static Generation
The most common generators of static electricity are
processes using flammable powders and liquids. Static
electricity is generated by materials flowing through pipes
and in mixing, pouring, pumping, filtering or agitating. The
rate of generation is influenced by conductivity, turbulence,
the interface area between the materials and other surfaces,
velocity and the presence of impurities.
96
Strip To Be Welded
Sandwich Pieces,
Top And Bottom,
Same Size As
Strip Being
Welded
CADWELD
Connection
ERITECH
Ground Rod
Fig. 6-11
Guyed Tower Ground Detail
Fig. 6-12
Contractor To Remove
Paint To Provide
Positive Connection.
Touch Up Paint After
Installation Of CADWELD
Connection
Exothermic Weld
CADWELD Type VA Or VS
Grade
External Building
Buried Ground Ring
Monopole
2'-0" Radius Bend
(Minimum, Typical)
#2 Solid
Tinned CU (Typ.)
CADWELD
To Ground Rod (Typ.)
Fig. 6-13
Crushed
Gravel
#2 AWG Tinned
CU (TYP.)
External Building Buried Ground Ring
Finished Grade
CADWELD Type
NC To Ground
Rod
Tower By Others
CADWELD Connection To
Leg Or To Cross Bracing
2'-0" Radius Bend
(Minimum, Typical)
Guy Anchor
CADWELD
Connection
Finished
Grade
#2 AWG, Tinned CU
#2 AWG, Tinned CU
Buried Ground Ring
ERITECH
Ground Rod
CADWELD
Connection
Fig. 6-14
NOTE: The statements contained in this section are based on the
experience of user. Each situation requiring static charge control
is different and is the total responsibility of the designer.
Grounding Book 4/14/99 10/5/99 6:02 PM Page 96 (Black plate)