Introduction to the
process of making exothermic welded connections.
is recognized internationally as the premium name in exothermic welding.
- The process was developed in 1938 for welding copper alloy signal
bonds to rails.
- Designed by Dr Charles Cadwell on behalf of ERICO, the process
CADWELD in recognition of his achievement.
- Exothermic is a chemical term describing a chemical reaction which
gives off heat as the reaction takes place.
- The burning of petrol in your car engine is an example of an exothermic
- CADWELD Grounding Connections are used to weld conductors
to conductors, conductors to ground rods, conductors to steel structures,
all in various configurations and to splice ground rods in deep driven
- CADWELD connections have also been used extensively in the
field of lightning protection with the same type of connections as used
- A CADWELD welded connection produces a joint, or connection,
superior in performance to mechanical, pressure type surface-to-surface
contact connector or brazed connections.
By virtue of it's molecular bond, a CADWELD welded connection
will not loosen or corrode, with the resultant increase in resistance,
over the lifetime of the connection - even under the harshest conditions.
- CADWELD connections replace several alternative, but lesser
quality and usually higher priced, methods of joining conductors for
- Bolted type connectors.
- Shear type bolted connectors.
- Crimp type connectors
- Circumferential compression connectors.
- There are several advantages to CADWELD exothermically welded
- Current carrying (fusing) capacity of the connection is equal to
that of the conductor.
- The connections will not deteriorate with age since they are welded
and therefore permanent.
- The connection is a permanent molecular bond that cannot loosen.
- The connections are unaffected by corrosive products to the same
degree as copper.
- The connections will withstand repeated high current surges (faults)
- Minimum training is required to make a connection.
- The material to make the connection is light and portable.
- No external power or heat is required to make a connection.
- The connections can be checked for quality by visual inspection.
- The connections can be used to weld copper, copper alloys, copper
clad steel, steel of various alloys including stainless steel and
high resistance heater materials.
ERITECH® Earth Rod Inspection Box PIT-03
Critical ground terminations require a high level of security to ensure their integrity under all conditions. In addition to this, regular maintainance of these terminations is often a requirement of end users to ensure the safety of personnel and equipment from earth fault currents and the high current levels injected into the ground system by lightning protection installations. The ERITECH PIT-03 offers this high level of protection through the use of its lockable lid.
- Strong durable construction compliant with BS5834 part 2 loading requirements for pavements
- Withstands over 5 tonnes
- Large working aperture, 147 mm x 192 mm (overall dimensions 245 x 190 x 145 mm)
- Lightweight (1.20kg)
- Lockable lid opened only with a security key
- For use in critical ground terminations where a high level of security is required
- Also ideal for installation in heavy traffic areas
- Suitable for both paving and hot tar applications
CADWELD® ONE SHOT
The CADWELD® ONE SHOT produces a permanent exothermic connection to a ground rod that will not loosen, corrode or increase in resistance for the life of the installation. A convenient, single-use ceramic mold eliminates the need for a mold and handle clamps and/or frames. Ideal for both threaded and plain copper-bonded ground rods.
- Easy to use, single-use ceramic mold eliminates need for mold and frame, handle clamp
- Produces permanent connection that will not loosen or corrode
- NEC® compliant, cULus® Listed
- Rural Utilities Service (RUS) accepted
The CADWELD ONE SHOT is ideal for making permanent reliable connections to ground rods for electrical transmission and distribution, telecommunications and cable television applications.
CADWELD ONE SHOT part numbers for type GR (one conductor to ground rod), type GT (two conductors to ground rod), type NT (three conductors to ground rod) and type NX (four conductors to ground rod):
GEM® - Ground Enhancing Material
ERICO’s Ground Enhancing Material (GEM) is a superior conductive material that improves grounding effectiveness, especially in areas of poor conductivity such as rocky ground, areas of moisture variation, and sandy soils.
- Effective-typical resistivity 12-18 Ohm cms (20 times lower than bentonite clay)
- Once in its “set” form, maintains constant resistance for the “life” of the ground system
- Performs in all soil conditions even during dry spells
- Permanent - does not dissolve, decompose or leach out with time
- Meets (USA) Environmental Protection Authority requirements for landfill
- Can be installed using Trench or Ground Rod Backfill methods
GEM is ideal for areas with poor conductivity such as rocky ground, mountain tops, sandy soil and areas of moisture variation.
Download the latest version of ERICO's GEM Software Calculator. Available in four languages (English, French, German and Spanish), the calculator estimates the amount of GEM required for an installation and converts Metric and Imperial measurement units.
How to Specify
- Ground enhancement material in its set form shall have a resistivity of not more than 20 ohm-cm
- Ground enhancement material must be permanent and maintenance-free (no recharging with salts or chemicals which may be corrosive) and maintain its earth resistance with time
- It must set up firmly and not dissolve or decompose or otherwise pollute the soil or the local water table
- The ground enhancement material shall be suitable for installation in a slurry form
- The ground enhancement material shall not depend on the continuous presence of water to maintain its conductivity
Ground Enhancing Material (GEM) Installation Methods