CADWELD & PGE

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Open Neutral

Senior Member
Location
Inside the Beltway
Occupation
Engineer
I was working on a job in NoCal where we'd be fed 3-ph by PGE.
They required 2 grounds for the pad-mount transformer.

Their "Green Book" specified the type of clamp.

I wanted to CADWELD the wire to the rod. They didn't want to accept that and could not explain why.

I did "when in Rome" and clamped the wire AND then CADWELDed it too.

But I still wonder -- why wouldn't they want a welded connection?
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
Depending on the size of the conductor, Cadwelds may have internal voids/pits that can reduce the cross-sectional area of the connection and reduce its effective ampacity. The phenomena can begin around #4 AWG. Truthfully, this isn't generally a serious problem with grounding electrode connections but it can be a big deal with some bonding connections.
 

Fulthrotl

~Autocorrect is My Worst Enema.~
I was working on a job in NoCal where we'd be fed 3-ph by PGE.
They required 2 grounds for the pad-mount transformer.

Their "Green Book" specified the type of clamp.

I wanted to CADWELD the wire to the rod. They didn't want to accept that and could not explain why.

I did "when in Rome" and clamped the wire AND then CADWELDed it too.

But I still wonder -- why wouldn't they want a welded connection?

more and more, i've seen specifications that want a compression connection,
and they want to be able to see the die number witness on the fitting.

in other words, burndy 12 ton press, and burndy dies. not universal, which i think
is a bunch of hooey, but it's 'cause the harbor freight crimpers that are metric, and
don't get things stuck together well enough.

it's been almost 10 years since i did a cadweld.
 

Julius Right

Senior Member
Occupation
Electrical Engineer Power Station Physical Design Retired
IEEE 142/2007 Green Book
4.3.3 Connecting to electrodes
Connections to electrodes are usually made by one of several means: mechanical, fusing,
or compression. The first of these methods, mechanical fittings, is best suited for making
connections to ground as the fittings are often easily disconnected, allowing for periodic
ground-to-earth measurements.
 

Open Neutral

Senior Member
Location
Inside the Beltway
Occupation
Engineer
My perspective is the biggest threat to a good ground is a corroded connection, 20 years after the fact. That's why I preferred welded connections.

I'm puzzled that the standards folks are seemingly unconcerned about that.
 

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
IEEE 142/2007 Green Book
4.3.3 Connecting to electrodes
Connections to electrodes are usually made by one of several means: mechanical, fusing,
or compression. The first of these methods, mechanical fittings, is best suited for making
connections to ground as the fittings are often easily disconnected, allowing for periodic
ground-to-earth measurements.

Easily disconnected, allowing for periodic
ground-to-earth measurements[
:thumbsup:
 
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