A PG clamp (parallel groove clamp) is an electrical connector used to join two parallel conductors without cutting or splicing them. It uses two parallel grooves and bolt pressure to create a secure, low-resistance electrical connection. PG clamps are widely used in overhead power distribution lines, grounding systems, service entrances, and industrial electrical installations.
Introduction
PG Clamps (Parallel Groove Clamps) are essential electrical connectors used to join two parallel conductors without cutting them. They provide strong mechanical support and a low-resistance electrical path, ensuring reliable performance in overhead distribution lines, service entrances, and industrial power systems.
In this guide, we’ll cover the types of PG clamps, their main components, installation steps, size and torque considerations, and tips for selecting the right clamp. Use the links below to navigate to detailed articles on each topic.
Table of contents
What is a PG Clamp?
A PG Clamp (Parallel Groove Clamp) is a type of electrical connector used to join two parallel conductors without cutting or splicing the wires. The name comes from its design: two parallel grooves hold the conductors side by side. Tightening the bolts applies mechanical pressure, creating a secure and low-resistance electrical connection.
PG clamps work on a simple but effective principle: mechanical pressure creates a reliable electrical connection. Think of it like a handshake between two wires—the grooves align them face to face, and the bolts provide the grip strength.
Key components: clamp body (aluminum or copper), grooves, bolts, nuts, and optional pressure pads or weather shields.
👉 Read more: Types of PG Clamps Explained →
Types of PG Clamps
PG clamps come in several configurations to suit different conductor sizes and applications:
- Single Bolt PG Clamp – Compact, for small conductors (service drops, grounding)
- Double Bolt PG Clamp – Balanced pressure for medium to large conductors (overhead distribution)
- Multi-Bolt PG Clamp – Highest clamping force for large conductors (utility, heavy industrial)
- Bimetallic PG Clamp – Copper-aluminum transition for connecting dissimilar metals
- Insulated PG Clamp – With insulating cover for live-line work and short-circuit prevention
- Universal Groove PG Clamp – Blended-radius grooves covering 8–10 conductor sizes
Quick selection: Residential service drop → single bolt; copper-to-aluminum → bimetallic; medium voltage overhead → double bolt; high voltage transmission → multi-bolt.
👉 Read more: Types of PG Clamps Explained →
Common Applications of PG Clamps
PG clamps are used wherever electrical conductors need to be joined without cutting or splicing:
- Overhead Power Distribution Lines – Tap connections, line extensions, conductor repairs
- Service Entrance Connections – Overhead service drops, residential meter connections
- Industrial Power Systems – Motor control centers, distribution panels, welding equipment
- Grounding Systems – Ground rod connections, equipment bonding, lightning protection
- Temporary Power Installations – Construction sites, events, emergency restoration
- Renewable Energy Systems (Solar/Wind) – Solar combiner boxes, DC collection systems
👉 Read more: PG Clamp Applications Guide →
PG Clamp Size Chart
Selecting the correct PG clamp size is critical. Below is a quick reference. For complete tables (JB, JBG, JBL, CAPG series), see the full guide.
Quick Selection by Conductor Size
| Conductor Size (mm²) | Conductor Size (AWG/kcmil) | Recommended Model |
|---|---|---|
| 16–25 | #6–#4 AWG | JB-0, JBG-1 |
| 35–50 | #2–1/0 AWG | JB-1, JBG-2 |
| 70–95 | 2/0–4/0 AWG | JB-2, JBG-3 |
| 120–150 | 250–350 kcmil | JB-3, JBG-3 |
| 185–240 | 400–500 kcmil | JB-4, JBG-4 |
| 300–400 | 600–750 kcmil | JB-5, JBG-5 |
| 500–630 | 1000–1750 kcmil | JB-6, JBG-6 |
For different-sized conductors: Use JBL Series
For copper-to-aluminum connections: Use CAPG Series
👉 Read more: Complete PG Clamp Size Chart (AWG, mm², ACSR) →
How to Install a PG Clamp
Proper installation is critical. Follow these key steps:
- Select the correct clamp – Match conductor material and size
- Prepare the conductors – Clean with wire brush, remove oxidation
- Apply anti-oxidant compound – Required for aluminum conductors
- Position conductors – Place fully into grooves
- Initial hand tightening – Ensure even alignment
- Final torque application – Use torque wrench to manufacturer’s specification
- Inspect the installation – Visual, mechanical, and electrical checks
Torque Reference (General)
- 5/16″ (M8): 8–12 ft·lbs (11–16 N·m) – Small single-bolt clamps
- 3/8″ (M10): 15–20 ft·lbs (20–27 N·m) – Standard distribution clamps
- 1/2″ (M12): 25–35 ft·lbs (34–47 N·m) – Heavy-duty double-bolt clamps
- 5/8″ (M16): 40–50 ft·lbs (54–68 N·m) – Utility-grade multi-bolt clamps
Common mistakes to avoid: Skipping conductor cleaning, no anti-oxidant on aluminum, incorrect torque, wrong size clamp.
👉 Read more: How to Install a PG Clamp (Step-by-Step Guide) →
PG Clamp vs Other Connectors
PG clamps are not the only solution. The table below compares PG clamps with several common electrical connectors used in power distribution systems.
| Feature | PG Clamp | C-Type Clamp | Wedge Clamp | IPC Connector | Compression Lug | Split Bolt |
|---|---|---|---|---|---|---|
| Reusability | Yes | Limited | No | No | No | Yes |
| Installation Tool | Wrench | Specialized torque tool | Wedge driver | Specialized crimp tool | Hydraulic crimper | Wrench |
| Relative Cost | Low | Medium | High | Medium | Low | Very Low |
| Best Application | Distribution taps | High-vibration lines | High-load lines | Fast insulated taps | Permanent terminations | Budget connections |
Choose PG clamps when: you need reliable, low-cost tap connections for bare conductors; crews carry standard tools; future reconfiguration is possible.
👉 Read more: PG Clamp vs IPC Connector vs Wedge Clamp →
How to Choose the Right PG Clamp
Follow this 5-step process:
- Identify conductor characteristics – Material, size, type
- Determine application requirements – Environment, mechanical demands
- Select clamp type – Match to application scenario
- Verify material compatibility – Aluminum-to-aluminum, copper-to-copper, or bimetallic for dissimilar metals
- Check standards and quality – IEC 61284, DIN 48072, NEMA CC 1
Material compatibility rules:
- Aluminum-to-aluminum → aluminum clamp + anti-oxidant compound
- Copper-to-copper → copper or aluminum clamp
- Copper-to-aluminum → bimetallic clamp required
- ACSR → aluminum clamp with ACSR-specific groove range
👉 Read more: How to Choose the Right PG Clamp →
Frequently Asked Questions (FAQs)
- What does PG clamp stand for? Parallel Groove.
- Can PG clamps be used on ACSR conductors? Yes, with correct sizing and compound.
- Do PG clamps require anti-oxidant compound? Required for aluminum; recommended for copper.
- Are PG clamps reusable? Yes, they can be removed and reinstalled.
- Can PG clamps be used on copper conductors? Yes, use copper or bimetallic clamps.
- How long do PG clamps last? Decades when properly installed.
- Are PG clamps suitable for outdoor environments? Yes, weather-resistant designs available.
- What materials are PG clamps made of? PG clamps are typically made from aluminum alloy, copper, or bimetallic copper-aluminum combinations. The bolts are usually galvanized steel or stainless steel to provide strength and corrosion resistance.
- Can PG clamps be used for temporary connections?
Yes. PG clamps are reusable and can be installed and removed multiple times, making them suitable for temporary power installations, construction sites, and emergency repairs.
Conclusion
The parallel groove clamp (PG clamp) is a simple but essential component in electrical power distribution. It connects two parallel conductors without cutting, using bolt-driven mechanical pressure to create a secure, low-resistance electrical path.
PG clamps are widely used because they are versatile (aluminum, copper, ACSR, and dissimilar metals), reusable, easy to install (standard tools only), and cost-effective. When installed correctly—clean conductors, anti-oxidant compound on aluminum, proper torque—a PG clamp provides reliable service for decades.
Choose the right type for your application: single bolt for small conductors, double or multi-bolt for larger ones, bimetallic for copper-to-aluminum connections, and universal groove to reduce inventory.
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