To select the correct PG clamp size, follow these steps:
1. Identify the conductor type (AAC, ACSR, or Copper)
2. Determine conductor size (AWG, mm², or kcmil)
3. Match the conductor diameter with the clamp groove range
4. Select the appropriate PG clamp series (JB, JBG, JBL, or CAPG)
5. Verify bolt count and torque requirements
The table below provides a quick reference for selecting a PG clamp based on conductor size.
Quick Selection Reference
| Conductor Size (Al/Cu) | Recommended Clamp |
|---|---|
| 16–25 mm² (#6–#4 AWG) | JB-0, JBG-1 |
| 35–50 mm² (#2–#1/0 AWG) | JB-1, JBG-2 |
| 70–95 mm² (#2/0–#4/0 AWG) | JB-2, JBG-3 |
| 120–150 mm² (250–350 kcmil) | JB-3, JBG-3 |
| 185–240 mm² (400–500 kcmil) | JB-4, JBG-4 |
| 300–400 mm² (600–750 kcmil) | JB-5, JBG-5 |
| 500–630 mm² (1000–1750 kcmil) | JB-6, JBG-6 |
For different-sized conductors: Use JBL Series
For copper-to-aluminum: Use CAPG Series
Table of Contents
- Quick Selection Reference
- Introduction
- Understanding Conductor Size Designations
- AWG/MCM to mm² Conversion Reference for PG Clamp Selection
- Detailed PG Clamp Size Charts by Series
- Which PG Clamp Series Should You Use?
- In Simple Terms
- How to Use a PG Clamp Size Chart
- Common Sizing Mistakes to Avoid
- Still Not Sure Which PG Clamp Size You Need?
- FAQ About PG Clamp Sizes
Introduction
Choosing the right PG clamp size isn’t just about matching numbers on a chart—it’s about understanding your conductor type, measuring correctly, and avoiding common mistakes that can lead to loose connections or overheating.
In this guide, you’ll learn:
- How to identify your conductor type (AWG, mm², kcmil, or ACSR)
- Which PG clamp series matches your application (JB, JBG, JBL, or CAPG)
- Step-by-step method to select the correct size
- Common sizing mistakes and how to avoid them
This article is part of our Complete PG Clamp Guide. For an overview of PG clamps, start there.
Understanding Conductor Size Designations
Before using any size chart, it is important to understand how conductors are measured and labeled:
- AWG – American Wire Gauge (smaller number = larger wire). Common in North American low-voltage applications.
- kcmil (MCM) – Thousand circular mils (area measurement). Used for large utility conductors.
- mm² – Cross-sectional area in square millimeters. International standard.
- ACSR – Aluminum Conductor Steel Reinforced (code words indicate size). Used for overhead transmission/distribution.
AWG/MCM to mm² Conversion Reference for PG Clamp Selection
For North American users, this conversion table helps match AWG/kcmil sizes to metric charts:
| AWG/kcmil | mm² (approx) | Typical PG Clamp Size |
|---|---|---|
| #6 AWG | 13.3 mm² | JB-0 / JBG-1 |
| #4 AWG | 21.1 mm² | JB-0 / JBG-1 |
| #2 AWG | 33.6 mm² | JB-0 / JBG-1 |
| #1/0 AWG | 53.5 mm² | JB-1 / JBG-2 |
| #2/0 AWG | 67.4 mm² | JB-1 / JBG-2 |
| #3/0 AWG | 85.0 mm² | JB-2 / JBG-2 |
| #4/0 AWG | 107.2 mm² | JB-2 / JBG-3 |
| 250 kcmil | 126.7 mm² | JB-3 / JBG-3 |
| 350 kcmil | 177.3 mm² | JB-3 / JBG-4 |
| 500 kcmil | 253.4 mm² | JB-4 / JBG-4 |
| 750 kcmil | 380.0 mm² | JB-5 / JBG-5 |
| 1000 kcmil | 506.7 mm² | JB-5 / JBG-5 |
| 1750 kcmil | 886.7 mm² | JB-6 / JBG-6 |
Below are the most common PG clamp size charts used in power distribution systems.
Detailed PG Clamp Size Charts by Series
The following charts are compiled from multiple manufacturers and represent common industry standards. Always consult the specific manufacturer’s catalog for exact specifications.
Chart 1: JB Series (Standard Aluminum PG Clamp)
The JB series is one of the most common PG clamp designs worldwide, suitable for aluminum and ACSR conductors in non-tension applications.
| Catalog No. | Conductor Area (mm²) | A (mm) | L (mm) | r (mm) | H (mm) | Weight (kg) |
|---|---|---|---|---|---|---|
| JB-0 | 16–25 | 38 | 72 | 3.5 | 42 | 0.2 |
| JB-1 | 35–50 | 46 | 80 | 5.0 | 53 | 0.4 |
| JB-2 | 70–95 | 54 | 114 | 7.0 | 65 | 0.7 |
| JB-3 | 120–150 | 64 | 140 | 8.5 | 70 | 1.1 |
| JB-4 | 185–240 | 72 | 144 | 11.0 | 75 | 1.3 |
| JB-5 | 300–400 | 100 | 215 | 15.0 | 100 | 3.9 |
| JB-6 | 500–630 | 110 | 230 | 18.0 | 120 | 5.1 |
Key specifications: Material: Aluminum alloy body with hot-dip galvanized steel bolts. Bolt count: JB-0 to JB-1 use 2 bolts; JB-2 to JB-6 use 2–3 bolts depending on size.
Chart 2: JBG Series (Compact PG Clamp)
The JBG series features a more compact design suitable for tighter spaces while maintaining comparable conductor ranges.
| Catalog No. | Conductor Area (mm²) | Conductor Dia (mm) | H (mm) | R (mm) | L (mm) | A (mm) | M (mm) | Weight (kg) | Bolt Qty |
|---|---|---|---|---|---|---|---|---|---|
| JBG-1 | 16–35 | 4.5–11.5 | 60 | 6.0 | 36 | 43 | 12 | 0.1 | 1 |
| JBG-2 | 50–70 | 11.5–14.0 | 55 | 7.0 | 60 | 52 | 12 | 0.4 | 2 |
| JBG-3 | 95–150 | 14.0–17.0 | 65 | 8.5 | 72 | 58 | 16 | 0.6 | 2 |
| JBG-4 | 185–240 | 17.0–22.0 | 70 | 11.0 | 80 | 72 | 16 | 0.8 | 2 |
| JBG-5 | 300–400 | 22.0–28.0 | 75 | 14.0 | 115 | 88 | 16 | 1.3 | 3 |
| JBG-6 | — | 28.0–37.0 | 90 | 18.5 | 175 | 108 | 16 | 2.6 | 4 |
Note: JBG-1 uses a single bolt; larger sizes use 2–4 bolts for increased clamping force.
Chart 3: JBL Series (Different-Sized Conductors)
The JBL series is specifically designed for connecting different-sized conductors (e.g., tapping from a larger main line to a smaller branch line).
| Catalog No. | Run Conductor (mm) | Tap Conductor (mm) | A (mm) | L (mm) | r (mm) | Weight (kg) |
|---|---|---|---|---|---|---|
| JBL-11 | 6.8–11.5 | 6.8–11.5 | 60 | 45 | 10 | 0.25 |
| JBL-22 | 10.1–15.3 | 10.1–15.3 | 80 | 52 | 10 | 0.32 |
| JBL-33 | 15.6–20.1 | 15.6–20.1 | 110 | 66 | 12 | 0.62 |
| JBL-44 | 19.0–24.0 | 19.0–24.0 | 120 | 76 | 16 | 0.82 |
| JBL-55 | 23.0–29.0 | 23.0–29.0 | 140 | 86 | 16 | 1.10 |
| JBL-12 | 10.1–15.3 | 6.8–11.5 | 80 | 50 | 10 | 0.30 |
| JBL-23 | 15.6–20.1 | 10.1–15.3 | 110 | 58 | 12 | 0.60 |
| JBL-34 | 19.0–24.0 | 15.6–20.1 | 120 | 72 | 16 | 0.75 |
| JBL-45 | 23.0–29.0 | 19.0–24.0 | 140 | 86 | 16 | 1.00 |
| JBL-24 | 19.0–24.0 | 10.1–15.3 | 120 | 66 | 16 | 0.70 |
| JBL-35 | 23.0–29.0 | 15.6–20.1 | 140 | 85 | 16 | 0.90 |
Naming convention: JBL-12 means Run size 1, Tap size 2 (different groove sizes for each conductor).
Chart 4: CAPG Series (Bimetallic PG Clamp)
Bimetallic clamps are designed specifically for connecting copper to aluminum conductors. They feature a copper contact surface on one side and aluminum on the other.
| Catalog No. | Copper (Cu) Range | Aluminum (Al) Range | Bolt Qty | Torque (N·m) |
|---|---|---|---|---|
| CAPG-A1 | 6–50 mm² | 16–70 mm² | 1 | 20–25 |
| CAPG-A2 | 10–95 mm² | 25–150 mm² | 1 | 20–25 |
| CAPG-B1 | 6–50 mm² | 16–70 mm² | 2 | 25–30 |
| CAPG-B2 | 10–95 mm² | 25–150 mm² | 2 | 25–30 |
| CAPG-C1 | 16–120 mm² | 16–120 mm² | 2 | 30–35 |
| CAPG-C2 | 50–240 mm² | 50–240 mm² | 2 | 35–40 |
| CAPG-D | 35–240 mm² | 35–300 mm² | 3 | 40–50 |
Key features: Hot-compressed copper-aluminum transition plate ensures good electrical contact. Prevents galvanic corrosion between dissimilar metals.
Which PG Clamp Series Should You Use?
Before looking at size tables, first determine which series fits your application:
| If you need… | Use this series |
|---|---|
| Standard aluminum or ACSR connection | JB Series |
| Compact, space-limited installation | JBG Series |
| Connecting different-sized conductors | JBL Series |
| Copper-to-aluminum connection | CAPG Series (required) |
In Simple Terms
Reading a PG clamp size chart is like finding the right shoe size:
- Conductor size is like your foot length—measure it first
- Catalog number is like the shoe size—match it to your measurement
- Different series (JB, JBG, JBL) are like different shoe brands—each fits slightly differently
- Bolt count is like lace tightness—more bolts mean stronger grip for bigger wires
When in doubt between two sizes, consult the manufacturer or choose the larger clamp if both options technically fit—but never exceed the specified maximum range.
How to Use a PG Clamp Size Chart
Follow these steps to select the correct PG clamp:
- Identify your conductor type – Aluminum stranded (AAC), ACSR (steel-reinforced aluminum), or Copper
- Measure or look up conductor diameter/area – For new installations, use the manufacturer’s specified dimensions; for existing lines, measure with a caliper
- Select appropriate chart based on application – JB for standard, JBG for compact, JBL for different sizes, CAPG for Cu-Al
- Verify the conductor falls within the specified range – Do not use conductors at the extreme upper limit; do not force a conductor that is too large
- Check bolt count and torque requirements – Larger conductors require more bolts for adequate clamping force
Common Sizing Mistakes to Avoid
- Using conductor diameter instead of area for metric charts – Always check chart units before selecting
- Assuming one size fits all conductor types – ACSR may require different sizing than AAC; use manufacturer’s ACSR-specific chart
- Selecting based on ampacity alone – Always verify physical dimensions
- Ignoring bolt count for large conductors – Select clamp with adequate bolt count for large conductors
Why These Mistakes Matter
- Using conductor diameter instead of area: Metric charts are based on mm² (cross-sectional area), not diameter. A 10mm diameter wire is not the same as 10mm²—this confusion alone causes most sizing errors.
- Assuming ACSR fits AAC sizing: ACSR has a steel core, so its overall diameter is smaller than an all-aluminum conductor of the same ampacity. Always use the manufacturer’s ACSR-specific chart.
Still Not Sure Which PG Clamp Size You Need?
Send us your conductor type, diameter, or cross-sectional area, and our engineers will recommend the correct PG clamp model for your project.
Contact Us for Sizing Assistance.
This article is part of our Complete PG Clamp Guide. For an overview of PG clamps, start there.
FAQ About PG Clamp Sizes
Choose a PG clamp whose groove range fully covers the conductor diameter. The conductor should not exceed the clamp’s maximum range.
Yes. PG clamps are commonly used for ACSR conductors, but the clamp must match the ACSR diameter range specified by the manufacturer.
An oversized clamp may not provide sufficient contact pressure, which can lead to high resistance, overheating, or connection failure.
If the conductor does not fit fully into the groove, the clamp may damage the conductor strands and fail to provide proper electrical contact.
Use a caliper to measure the outer diameter of the conductor.
Then compare the measurement with the clamp’s specified groove range in the manufacturer’s size chart.
