GUV Clamps

GUV Clamps

GUV clamps — also called GUV-type grounding clamps, earth rod clamps, or ground rod bonding clamps — are bronze cast clamps designed to bond a copper grounding conductor directly to a driven copper-bonded earth rod or ground rod. The GUV designation (used across British and international earthing standards) refers to the rod-clamp geometry: a U-bolt or C-body clamp with a single clamping bolt that secures the conductor against the rod body. Manufactured by Electrical Accessories India (Jamnagar) from silicon bronze C65100 and gunmetal LG2 (CC491K), these clamps comply with BS 7430, IS 3043, IEC 62561-4, and IEEE Std 80, and are used in substation earthing, tower earthing, industrial grounding grids, and lightning protection systems.

Product Overview

GUV Clamp Design and Geometry

The GUV clamp body is a solid bronze casting featuring a concave rod-seat profiled to accept round earth rod diameters (typically 5/8″ / 16 mm or 3/4″ / 19 mm), and a conductor channel machined to accept stranded copper conductor or copper tape. The clamping action is achieved through a stainless steel or silicon bronze hex-head bolt that draws the conductor securely into the conductor channel and against the rod. This single-bolt design allows rapid installation by one person without specialised tools. The clamp maintains permanent electrical contact between the rod and conductor even under mechanical vibration, thermal cycling, and soil movement. Related terms: earth rod clamp, ground rod clamp, GUV earthing clamp, rod-to-cable clamp, IEC 62561-4 Type A rod clamp.

Material: Silicon Bronze and Gunmetal LG2

GUV clamps are produced in silicon bronze (UNS C65100 / C65500) and gunmetal LG2 (CC491K / IS 318), both selected for high corrosion resistance in buried earthing applications. Silicon bronze’s Cu-Si-Mn alloy composition resists dezincification and stress-corrosion cracking, making it superior to standard brass in acidic, saline, or moist soils. Gunmetal LG2 (85% Cu, 5% Sn, 5% Zn, 5% Pb) offers excellent castability for the complex clamp body geometry and provides dependable long-term performance in earthing environments. Clamping bolts are SS316 stainless steel for bi-metallic compatibility. All materials are non-magnetic and non-sparking — suitable for hazardous-area (ATEX Zone 1/2) earthing. Related standards: ASTM B98 (silicon bronze), IS 318 / BS EN 1982 (gunmetal LG2), IEC 62561-4.

Conductor Compatibility and Range

GUV clamps from Electrical Accessories India are available in a range of conductor channel sizes accommodating bare stranded copper conductors from 16 mm² to 300 mm² (cross-section) and copper tape up to 40 mm × 4 mm. The clamp body is sized to the conductor range, and the rod seat is matched to the earth rod diameter. A size matrix approach is used: for example, a GUV 70-16 clamp accepts 50–95 mm² conductor on a 16 mm (5/8″) rod. The conductor channel is designed with a smooth radius to avoid strand damage during tightening. Conductor-to-rod contact area typically exceeds 200 mm², ensuring low contact resistance at the joint. Related terms: copper tape grounding clamp, stranded conductor earth clamp, bare copper bonding clamp, substation grounding conductor clamp.

Electrical Performance and Contact Resistance

When correctly torqued, the GUV clamp achieves contact resistance typically below 0.1 mΩ between conductor and rod. This performance is verified per IEC 62561-4 Clause 6.4 current cycle test and short-circuit withstand test. The clamp is rated to carry the maximum prospective earth fault current for the earthing system design — typically 10 kA to 40 kA for 0.1 s to 1 s duration depending on substation rating. Thermal stability of the clamp body and bolt under fault current is verified by temperature-rise testing per IEC 62561. Related performance parameters: fault current withstand, short-time current rating, contact resistance, thermal stability.

Installation and Torque Requirements

GUV clamps are installed after the earth rod is driven to depth. The conductor is laid into the conductor channel, and the clamping bolt tightened to the rated torque (typically 25–40 N·m depending on clamp size). Anti-seize compound (copper-based or Vaseline) should be applied to bolt threads per IEEE Std 80 recommendations to prevent galvanic seizing in buried conditions. After tightening, the assembly is inspected for correct seating before backfilling. No special tools are required beyond a standard hex/socket wrench. Re-tightening after one year of service is recommended where soils are subject to frost heave or settlement. Related terms: earth rod clamp torque, grounding clamp installation, buried conductor termination, IS 3043 earthing clamp.

Standards Compliance and Type Testing

GUV clamps are manufactured and tested per IEC 62561-4 (Requirements for conductor clamps), IS 3043 (Code of Practice for Earthing), BS 7430 (Protective Earthing), and IEEE Std 80 (Substation Grounding Guide). Type tests include: current cycle test (100 cycles at rated current), short-circuit withstand test, corrosion resistance test (salt spray / SO₂ exposure), and pull-out force test. Batch inspection includes dimensional checks, material verification by XRF, and visual inspection. Full IEC 62561-4 type test reports are available for specification-critical projects.

Key Features

• GUV-type single-bolt bronze clamp for earth rod-to-conductor bonding
• Available in silicon bronze C65100/C65500 and gunmetal LG2 (CC491K)
• Conductor range: 16 mm² to 300 mm² stranded copper; copper tape up to 40×4 mm
• Rod diameter: 5/8″ (16 mm) and 3/4″ (19 mm) standard; custom sizes available
• SS316 clamping bolt for corrosion resistance and bi-metallic compatibility
• Non-sparking, non-magnetic — ATEX Zone 1/2 suitable
• Contact resistance: <0.1 mΩ when correctly torqued
• Short-circuit withstand: rated per IEC 62561-4
• Compliant: IS 3043, BS 7430, IEC 62561-4, IEEE Std 80
• Type test reports available for IEC 62561-4

Material Grades and International Equivalents

Technical Specifications

Product Types and Variants

• GUV Single-Bolt Clamp: Standard rod-to-conductor clamp for stranded copper conductors 16–150 mm²
• GUV Large Conductor: 150–300 mm² conductor range, deeper conductor channel, M12 bolt
• GUV Tape Clamp: Conductor channel profiled for flat copper tape (20×3 mm to 40×4 mm)
• GUV Two-Conductor: Double-channel body accepting two conductors simultaneously on one rod
• GUV with Stainless Steel Insert: SS316 rod contact pad for use with stainless earth rods

Applications in Industry

• Power Substations (HV/MV/LV): Bonding earth conductor network to driven copper-bonded rods per IS 3043 / IEEE Std 80 earthing grid design
• Transmission Towers: Tower footing conductor-to-rod bonding at each tower leg
• Telecom / BTS Sites: Single-rod earthing with conductor bonding for sensitive electronic equipment
• Industrial Plants: Equipment earthing and bonding in chemical, petrochemical, and manufacturing facilities
• Solar / Wind Farms: DC earthing and grounding of inverters, trackers, and substation equipment
• Lightning Protection: Down conductor termination to earth electrodes per IEC 62305-3
• Railway / Metro: OLE (overhead line equipment) and trackside equipment earthing
• Oil and Gas (ATEX): Non-sparking clamps for grounding in Zone 1/2 explosive atmospheres

Manufacturing Process

1. Pattern and Mould: Cast clamp body from certified silicon bronze or LG2 ingot using permanent mould or sand casting
2. Fettling: Removal of casting flash, risers; visual inspection for porosity and cracks
3. CNC Machining: Rod-seat radius and conductor channel machined to close tolerances on CNC lathes and machining centres
4. Bolt Hole Drilling and Threading: M10/M12 thread cut for bolt; counter-bore for bolt head where specified
5. Material Verification: XRF spectrometry of each casting lot
6. Dimensional Inspection: Rod seat diameter, conductor channel width and depth checked per drawing
7. Assembly: SS316 bolt and washer assembled; torque-tested on sample basis
8. IEC 62561-4 Testing: Current cycle and short-circuit tests performed on sample batches
9. Packing: Individual poly bag; bulk carton with MTC and test certificate

Quality Standards and Certifications

• IEC 62561-4 – Requirements for Conductor Clamps for Lightning Protection
• IS 3043 – Code of Practice for Earthing (India)
• BS 7430 – Code of Practice for Protective Earthing of Electrical Installations (UK)
• IEEE Std 80 – Guide for Safety in AC Substation Grounding (USA)
• ASTM B98 / BS EN 12163 – Silicon Bronze bar and rod
• BS EN 1982 / IS 318 – Gunmetal LG2 castings
• ISO 9001:2015 – Quality Management System

Why Choose Electrical Accessories India

• Specialist manufacturer of bronze earthing hardware with 30+ years in Jamnagar, India
• In-house casting, CNC machining, and IEC 62561-4 type testing capability
• Both silicon bronze and LG2 gunmetal available — right material for your soil conditions
• Clamp-rod compatibility tested with our own copper-bonded earth rod range
• Type test reports per IEC 62561-4 available for specification-critical projects
• Export documentation: MTCs, dimensional reports, XRF certificates, RoHS declarations
• Custom conductor channel sizes and rod seat diameters machined to drawing
• Delivery to 30+ countries: UK, USA, UAE, Australia, South Africa, Nigeria, Singapore

Frequently Asked Questions (FAQ)

What does GUV stand for in GUV clamp?

GUV is a product designation used in British and international earthing hardware standards for a single-bolt rod-to-conductor grounding clamp. The term describes the clamp geometry and application: a cast or forged body with a concave rod seat and a conductor channel, secured by a single bolt. It is also called an earth rod clamp or ground rod bonding clamp.

What conductor sizes do GUV clamps accommodate?

Our GUV clamps accommodate bare stranded copper conductors from 16 mm² to 300 mm² and copper tape up to 40 mm × 4 mm. Different clamp body sizes cover different conductor ranges — specify your conductor cross-section and rod diameter when ordering.

Why use silicon bronze rather than brass for GUV clamps?

Silicon bronze (C65100/C65500) offers superior resistance to dezincification and stress-corrosion cracking compared to standard leaded brass. In buried earthing applications — especially in coastal, acidic, or moist soils — silicon bronze provides significantly longer service life. For high-stress environments, silicon bronze is the preferred material per BS 7430 and IEC 62561 guidance.

Are the clamping bolts included with the clamp?

Yes. GUV clamps are supplied as complete assemblies with SS316 stainless steel hex-head bolt and washer. Silicon bronze bolts can be substituted on request for environments where SS316 may be unsuitable.

What is the difference between a GUV clamp and a rod clamp for above-ground connections?

GUV clamps are designed for direct burial alongside the earth rod. They are made from corrosion-resistant bronze and do not rely on additional protection. Above-ground rod clamps may use brass or aluminium and are suitable only where they are not buried. Always use silicon bronze or LG2 gunmetal GUV clamps for buried applications.

Can GUV clamps be used with solid copper rods as well as copper-bonded rods?

Yes. GUV clamps are compatible with copper-bonded steel core rods, solid copper rods, and stainless steel earth rods. The rod seat diameter must match the rod OD. For stainless rods, the SS316 insert variant is recommended to avoid galvanic issues at the contact point.

What torque should be applied to the GUV clamp bolt?

Recommended tightening torque is 25 N·m for M10 bolts and 35–40 N·m for M12 bolts, based on conductor cross-section and clamp size. Always use a calibrated torque wrench and apply anti-seize compound to the bolt threads before installation in buried service.

Do you supply GUV clamps with IEC 62561-4 type test reports?

Yes. Type test reports per IEC 62561-4 are available for our standard GUV clamp sizes. For project specifications requiring third-party test certification, please request this at the inquiry stage.

Can GUV clamps connect two conductors to one earth rod?

Yes. Our double-channel GUV variant accommodates two conductors simultaneously on a single earth rod — useful for substation ring earthing conductors where both sides of the loop terminate at the same electrode.

Equivalent Terms – Multilingual Reference

Related Products and Linked Terms

• Copper Bonded Earth Rods
• Bronze Ground Rod Clamps
• Bronze Grounding Pipe Clamps
• Bronze Copper Grounding Clamps
• Bronze Transformer Ground Connectors
• Silicon Bronze Castings
• Aluminum Bronze Casting
• Hotline Clamps of Bronze
• Bronze Ground Rod Couplers – Earth Rod Couplers
• Brass Earth Blocks

Request a Quote

To request pricing and lead time for GUV grounding clamps, please specify: rod diameter (5/8″ or 3/4″), conductor cross-section (mm²) or tape size, material preference (silicon bronze or LG2 gunmetal), quantity, and whether IEC 62561-4 type test reports are required.

Contact us: Send your RFQ with quantity, conductor specification, and delivery requirement. We respond within 24 business hours. Export to 30+ countries with full shipping documentation.