How it connects
Conductors are laid in the grooves between the jaws; tightening the bolt(s) clamps the jaws onto them, making electrical contact by pressure. Not sealed; oxide-inhibiting compound is often used on aluminum.
Male and female halves
Not a male/female pair. The clamp's grooves are the receiving (female) side and the bare conductor is what goes in; 'female' in this name just means the clamp side.
Usually connects to
- bare stranded conductors (copper, aluminum, ACSR)
- ground wires and guy/messenger strand
Common sizes
- Sized by conductor range per groove, typically from about #8 AWG to 4/0 AWG and larger (up to several hundred kcmil) for distribution and transmission; one-, two- or three-bolt versions.
Where it is used
overhead power distributionservice drops and tapsgroundingelectrical utility lines
Variations
- two-bolt
- three-bolt
- aluminum (Al-Al / Al-Cu)
- copper / bronze
- with bimetallic liner for Cu-Al
How to recognise it
A small metal block made of two jaw halves with two parallel half-round grooves (often serrated) between them and one or more carriage or hex bolts through the middle; conductor size ranges are usually cast or stamped on the body.
Often confused with
| Confused with | How to tell them apart |
|---|---|
| Split bolt connector | A split bolt is a slotted threaded bolt with a nut and has no separate side-by-side grooves; a PG clamp has two jaws with two grooves and one or more through-bolts. |
| Insulation piercing connector | IPCs have an insulated housing and teeth that cut through the cable insulation; PG clamps are bare metal and grip bare conductors. |
| Wedge connector | Wedge connectors use a C-shaped body and a driven wedge, with no clamping bolt. |
Also called
parallel groove clampPG clampbolted parallel groove connectorparallel groove tap connector
Good to know
The sample part is Commercial Electric GOEC-12 (2–4/0 AWG, single bolt, aluminum). Each groove is a port that takes one conductor. I recalled the standards (ANSI C119.4, UL 486A-486B) from memory and did not check them against a source.
Related connections
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