690 Volt Industrial Fuse-Links to IEC 60269-2/BS 88-2 – Type SS

690V Industrial Fuse-Links to IEC 60269-2 / BS 88-2 – Type SS 690V Industrial Fuse Links | BS88 Size A1–C3 Fuse 600V | BS Bolted Type 690V Fuse

Product Introduction

The Lawson Type SS is the comprehensive 690V Industrial Fuse Links range for use in industrial applications where higher supply voltages — typically 600V, 660V, or 690V — demand a fuse-link rated above the standard 415V BS industrial range. As a BS Bolted Type fuse-link certified to IEC 60269-2 and BS 88-2, the Type SS covers the complete spectrum of BS 88 size references from BS88 Size A1 through to BS88 Size C3, in current ratings from 2A to 800A — providing a 690V equivalent of the full Type N&T 415V industrial range for applications where the higher voltage rating is required.

Approved by leading authorities including Electricity Supply Authorities, the Lawson Type SS 690V Industrial Fuse Links can be fitted in Lawson Type LBI Boltin fuse-holders or suitable distribution fusegear. The range includes both central tag and offset tag variants, covering all standardised and additional non-standard fixing centre dimensions — giving panel builders, switchgear manufacturers, and electrical engineers the complete BS88 Size A1 to C3 Fuse 600V solution from a single UK manufacturer.

Key Features

• 690V Industrial Fuse Links — rated 690V a.c. / 250V d.c. for higher-voltage industrial installations
• Breaking capacity: 80kA a.c. / 40kA d.c. — rated for the highest fault levels in industrial installations
• Utilisation categories gG and gM — general purpose and motor circuit protection variants
• Covers BS88 Size A1 (SSA1), A2 (SSA2), A3 (SSA3), A4 (SSA4) — offset tag fuse-links 2A to 200A
• Covers BS88 Size B1 (SSB1/SSBC), B2 (SSB2), B3 (SSB3), B4 (SSB4) — central tag fuse-links 2A to 400A
• Covers BS88 Size C1 (SSC1), C2 (SSC2), C3 (SSC3) — large central tag fuse-links 355A to 800A
• D1 size (SSLU) also available — 450A to 800A
• Additional non-standard fixing centre variants available: 85SSM, 86SST, SSMT, SST, SSLT, 84SSF, 84SSK, SSKM
• Compliant with IEC 60269-2 and BS 88-2 — internationally certified industrial fuse standard
• Approved by Electricity Supply Authorities
• Compatible with Lawson Type LBI Boltin Industrial Fuse-Holders

BS 88 Size Reference Guide — 690V

Offset Tag Fuse-Links

BS88 Size A1 — SSA1 (44.5mm fixing centres, 2A–20A) The BS88 A1 Fuse 600V (SSA1 series) is the smallest offset tag 690V fuse-link, with 44.5mm (1¾ inch) fixing centres covering 2A to 20A. Used in industrial sub-circuit and control circuit protection at 690V where the smaller A1 size is appropriate.

BS88 Size A2 — SSA2 (73mm fixing centres, 2A–32A) The BS88 A2 Fuse 600V (SSA2 series) covers 2A to 32A at 73mm (2⅞ inch) fixing centres — the 690V equivalent of the TIA A2 series from the Type N&T range. Suitable for sub-circuit and motor circuit protection in 690V industrial installations.

BS88 Size A3 — SSA3 (73mm fixing centres, 40A–63A) The BS88 A3 Fuse 600V (SSA3 series) covers 40A to 63A at 73mm fixing centres — the 690V equivalent of the TIS A3 series. Used for higher-current sub-circuit and motor circuit protection in 690V panels.

BS88 Size A4 — SSA4 / SSFP (94mm fixing centres, 32A–200A) The BS88 A4 Fuse 600V (SSA4 and SSFP series) covers 32A to 200A at 94mm (3 11/16 inch) fixing centres — the largest offset tag size in the Type SS range. Used for higher-current sub-circuit and feeder circuit protection in 690V industrial installations.

Central Tag Fuse-Links

BS88 Size B1 — SSB1 / SSBC (111mm fixing centres, 2A–100A) The BS88 B1 Fuse 600V (SSB1 and SSBC series) covers 80A and 100A (SSB1) and 2A–63A (SSBC, as B1) at 111mm (4⅜ inch) fixing centres. The SSB series (97mm, 3 13/16 inch) also covers 2A–63A as a non-standard fixing centre variant.

BS88 Size B2 — SSB2 / 84SSF (111mm / 99mm fixing centres, 125A–200A) The BS88 B2 Fuse 600V (SSB2 at 111mm and 84SSF at 99mm fixing centres) covers 125A, 160A, and 200A in the central tag format at 690V.

BS88 Size B3 — SSB3 / 84SSK / SSKM (111mm / 99mm / 133mm fixing centres, 250A–315A) The BS88 B3 Fuse 600V (SSB3, 84SSK, and SSKM series) covers 250A and 315A across three fixing centre options — 111mm, 99mm (3 29/32 inch), and 133mm (5¼ inch) respectively.

BS88 Size B4 — SSB4 (111mm fixing centres, 355A–400A) The BS88 B4 Fuse 600V (SSB4 series) covers 355A and 400A at 111mm fixing centres — the 690V equivalent of the TMF B4 series from the Type N&T range.

BS88 Size C1 — SSC1 / SSMT (133mm / 165mm fixing centres, 355A–400A) The BS88 C1 Fuse 600V (SSC1 at 133mm G1 / 184mm G2, and SSMT at 165mm G1 / 229mm G2) covers 355A and 400A — the large central tag 690V fuse-link for primary distribution applications.

BS88 Size C2 — SSC2 / SST (133mm / 165mm fixing centres, 450A–630A) The BS88 C2 Fuse 600V (SSC2 at 133mm G1 / 184mm G2, and SST at 165mm G1 / 229mm G2) covers 450A, 500A, 560A, and 630A — for high-current main distribution at 690V.

BS88 Size C3 — SSC3 / SSLT (133mm / 165mm fixing centres, 670A–800A) The BS88 C3 Fuse 600V (SSC3 at 133mm G1 / 184mm G2, and SSLT at 165mm G1 / 229mm G2) covers 670A, 710A, 750A, and 800A — the largest central tag 690V fuse-link in the Type SS range, for the most demanding industrial primary distribution fusing at 690V.

Applications

The Lawson Type SS 690V Industrial Fuse Links range is specified across high-voltage industrial and commercial applications:

• 690V industrial motor drives and variable speed drive (VSD) systems — high-voltage motor circuit and drive input protection
• Offshore and marine installations — 690V distribution in offshore platform, FPSO, and ship electrical systems
• Heavy industrial plant — steelworks, chemical processing, petrochemical, and mining installations with 660V/690V supplies
• High-voltage industrial distribution boards and MCCs — BS88 A1 to C3 Fuse 600V for main and sub-circuit fusing at 690V
• Transformer primary and secondary protection — 690V primary side fusing for step-down transformers in industrial installations
• Railway and traction applications — rolling stock and infrastructure power supply fusing at higher voltages
• Renewable energy and power conversion — 690V inverter and converter input fusing in wind, solar, and industrial power conversion equipment

Why Choose Lawson Type SS?

The Lawson Type SS 690V Industrial Fuse Links range mirrors the complete BS88 size coverage of the Type N&T 415V range — from BS88 Size A1 Fuse 600V through to BS88 Size C3 Fuse 600V — but rated at the higher 690V a.c. voltage required for offshore, marine, heavy industrial, and high-voltage motor drive applications. Approved by Electricity Supply Authorities and compliant with IEC 60269-2 and BS 88-2, the Type SS is the trusted high-voltage industrial fuse-link for engineers and panel builders who need the full range of BS industrial fuse sizes at 690V.

All products are manufactured under an ISO 9001 accredited quality management system with test facilities accredited to ISO/IEC 17025, and are ASTA Certified to the ASTA 20 Scheme — providing the performance assurance and traceability demanded by high-voltage industrial applications.

Q1. What is the Lawson Type SS 690V Industrial Fuse Link?

The Lawson Type SS is a range of 690V Industrial Fuse Links with bolted tag connections for use in industrial installations requiring fuse protection at 600V, 660V, or 690V a.c. It covers BS 88 size references from BS88 Size A1 through to BS88 Size C3, in current ratings from 2A to 800A, and is the 690V equivalent of the Lawson Type N&T 415V industrial fuse-link range. All Type SS fuse-links comply with IEC 60269-2 and BS 88-2, and have been approved by Electricity Supply Authorities.

Q2. What is the difference between the 415V Type N&T and the 690V Type SS?

Both the Type N&T and Type SS are BS bolted-tag industrial fuse-links conforming to IEC 60269-2 and BS 88-2, covering the same BS88 size references (A1 through C3) and similar current rating ranges. The fundamental difference is voltage rating — the Type N&T is rated at 415V a.c. / 250V d.c. for standard UK three-phase industrial installations, while the Type SS is rated at 690V a.c. / 250V d.c. for higher-voltage systems including offshore, marine, 690V motor drives, and heavy industrial installations. The two ranges use the same physical fixing centre dimensions and BS88 size references but the fuse-links are not interchangeable due to their different voltage ratings.

Q3. What BS88 sizes are available in the Type SS 690V Industrial Fuse Links range?

The Type SS covers the full spectrum of BS88 size references: BS88 A1 Fuse 600V (SSA1), BS88 A2 Fuse 600V (SSA2), BS88 A3 Fuse 600V (SSA3), BS88 A4 Fuse 600V (SSA4/SSFP) in offset tag format, and BS88 B1 (SSB1/SSBC), BS88 B2 (SSB2), BS88 B3 (SSB3), BS88 B4 (SSB4), BS88 C1 (SSC1), BS88 C2 (SSC2), and BS88 C3 (SSC3) in central tag format — plus D1 (SSLU) and various non-standard fixing centre variants.

Q4. Why would I need a 690V fuse-link rather than a standard 415V type?

You need a 690V Industrial Fuse Link when the electrical installation operates at supply voltages between 415V and 690V a.c. — typically in offshore oil and gas platforms, marine vessels, heavy industrial plant, 690V motor drive systems, or European industrial installations where 660V or 690V three-phase supplies are standard. Using a 415V-rated fuse-link in a 690V circuit is a serious safety hazard — the fuse may fail to safely interrupt a fault arc at the higher voltage, risking equipment damage, fire, or electrical injury.

Q5. What breaking capacity does the Lawson Type SS 690V Industrial Fuse Link have?

The Lawson Type SS 690V Industrial Fuse Links have a breaking capacity of 80kA a.c. at 690V and 40kA d.c. at 250V — sufficient to safely interrupt the highest fault currents encountered in 690V industrial electrical systems.

Q6. What fixing centre options are available for BS88 C3 Fuse 600V?

The BS88 C3 Fuse 600V (670A–800A) is available in two fixing centre configurations: SSC3 series with G1 = 133mm and G2 = 184mm, and SSLT series with G1 = 165mm and G2 = 229mm — as well as the SSLU D1 series at 149mm G1 and 32mm G2. Always confirm the fixing centre dimension of the fuse holder or distribution equipment before ordering the correct BS88 C3 Fuse 600V variant.

Q7. What fuse holder is compatible with the Lawson Type SS 690V Industrial Fuse Links?

The Type SS 690V Industrial Fuse Links are designed for use with the Lawson Type LBI Boltin Industrial Fuse-Holders (rated 690V), as well as other suitable BS 88-2 compliant industrial fusegear and switchfuse equipment rated for 690V operation. The BS88 size reference (A1 through C3) and fixing centre dimension of the fuse-link must match the holder or fusegear being used.

Q8. How do I select the correct BS88 size for my 690V application?

Selecting the correct BS88 Size Fuse 600V variant requires matching the BS88 size reference to the existing fuse holder or distribution equipment in the panel — determined by the physical fixing centre dimension. The current rating is then selected based on the circuit’s design current and load type (gG for general purpose circuits, gM motor protection variants for motor circuit applications). Contact the Lawson Fuses technical sales team for application guidance on selecting the correct 690V Industrial Fuse Link for your specific installation.