IS 17048 : 2018Halogen-free, low smoke (HFFR) cables for working voltages up to and including 1100 V

IS 17048 is the specification for Halogen-free, Low Smoke (HFFR) cables for working voltages up to and including 1100 V — the strictest fire-safety cable grade in Indian practice, covering cable insulation, sheath, and overall cable design + testing. HFFR cables are mandated for high-occupancy public buildings + critical infrastructure where fire-safety risks are paramount.

Use IS 17048 HFFR cables when designing electrical installations in: - Hospitals + nursing homes — patient evacuation difficult; toxic gas during fire is unacceptable - Schools + colleges — child evacuation; mandatory by State Fire Service in many states - Hotels + motels — overnight occupants; long evacuation time - Theatres + cinemas — high occupancy density; rapid evacuation needed - Shopping malls + multiplexes — high foot traffic, complex egress - Metro stations + airports — large enclosed public spaces - Data centres + server rooms — fire suppression by gas (CO₂ / FM200) requires no extra HCl gas - Railway stations + train coaches — large passenger volumes - Petrochemical plants + refineries — additional fire load + criticality - Defence + nuclear facilities — mission-critical operations

HFFR cables differ from regular FR / FRLS cables: - Halogen content < 0.5 % — no chlorine, no fluorine, no bromine in insulation - No HCl emission during burning — protects evacuating people from toxic + corrosive gas - Low smoke emission — > 50 % light transmission during burning (visibility maintained) - Low corrosivity — pH ≥ 4.3 of acid solution from burning gases - Higher fire resistance — generally meet IEC 60332-3 Cat A/B/C (vertical cable bundle flame test)

IS 17048 supersedes / supplements IS 7098 series (XLPE cables) and IS 1554 series (PVC cables) for projects requiring HFFR-grade fire safety.

HFFR cable construction:

1. Conductor — copper or aluminium; standard sizes 1.5 to 630 mm² (per IS 8130:2013) 2. Insulation — Cross-linked polyethylene (XLPE) OR ethylene-propylene rubber (EPR); HFFR formulation; halogen content < 0.5 % 3. Bedding (optional) — HFFR polymer 4. Armour (where required) — galvanised steel wire / strip; for mechanical protection in laid-direct or industrial environments 5. Inner sheath — HFFR thermoplastic compound 6. Outer sheath — HFFR thermoset compound; UV / weather resistant for outdoor use

Core configuration: - 1-core: large single-phase, rare - 2-core: single-phase + neutral OR earth - 3-core: 3-phase no neutral - 3.5-core: 3-phase + reduced neutral (industry standard) - 4-core: 3-phase + full neutral OR 3-phase + earth - Multi-core (5-37+): control + signal cables

Voltage rating: - 1100 V grade (IS 17048): standard for LV building services - Higher voltages (3.3 kV, 11 kV, 33 kV): separate codes (IS 7098 Part 2 / 3 with HFFR variants)

IS 17048:2018 acceptance criteria:

| Property | Acceptance | |---|---| | Halogen content (HCl + HBr + HF emission) | < 0.5 % | | Acid gas emission pH (gas dissolved in water) | ≥ 4.3 (less corrosive) | | Smoke density (transmittance during burning) | > 60 % at standard test | | Fire propagation (IEC 60332-3 Cat A) | Pass — no propagation along vertical cable bundle | | Insulation tensile strength | XLPE: ≥ 12.5 MPa; EPR: ≥ 4.2 MPa | | Insulation elongation at break | XLPE: ≥ 200 %; EPR: ≥ 200 % | | Operating temperature (continuous) | 90 °C (XLPE) | | Short-circuit temperature (5 sec) | 250 °C | | UV resistance (outdoor outer sheath) | 1000 hr accelerated weathering, no degradation |

Cable sizing thumb-rule (per IS 732:1989 ampacity tables):

| Conductor size (mm² Cu) | Continuous current (A, ambient 30 °C, in conduit) | |---|---| | 1.5 | 18 | | 2.5 | 24 | | 4 | 32 | | 6 | 41 | | 10 | 57 | | 16 | 76 | | 25 | 101 | | 35 | 125 | | 50 | 151 | | 70 | 192 | | 95 | 232 | | 120 | 269 | | 150 | 309 | | 185 | 353 | | 240 | 415 | | 300 | 478 |

(Multiply by 0.85 for de-rating in cable tray / ducts; multiply by 0.7 for buried direct.)

Voltage drop limit: ≤ 3 % from supply intake to farthest fixture (per IS 732:1989).

Cost premium: - IS 17048 HFFR cable: 30-50 % more expensive than standard PVC FR cable (same conductor size) - 1.5 mm² Cu HFFR (4-core): ~₹150-200/m vs PVC FR ~₹100-130/m - 50 mm² Cu HFFR (3.5-core): ~₹1500-2000/m vs PVC FR ~₹1000-1300/m - Project-level cost impact: 10-20 % of total cabling cost (depends on cable share of project)

Marking on cable (per IS 17048): - IS 17048 - Manufacturer name / trademark - Conductor material + size + cores - Voltage rating - HFFR / LSZH designation - Year of manufacture - ISI mark / BIS licence number

• IS 732:1989 — code of practice for electrical wiring installations.
• IS 1646:1997 — code of practice for fire safety of buildings (electrical installations).
• IS 3043:2018 — code of practice for earthing.
• IS 8130:2013 — conductors for insulated electric cables and flexible cords.
• IS 7098 Part 1:1988 — XLPE insulated cables for working voltages up to 1.1 kV.
• IS 1554 Part 1:1988 — PVC insulated armoured cables (the previous-generation alternative).
• IS 5831 — manufactured marine cables.
• IS 10810 — methods of test for cables (FR / FRLS / LSZH grade verification).
• IS 17047 — cables for fire-resistant cables (separate code for circuit-integrity-rated cables).
• IEC 60332 (multi-part) — international flame test standards (HFFR cables comply).
• IEC 60754 — international halogen content + acid gas test.
• NBC 2016 Part 4 — Fire and Life Safety (the umbrella fire code).
• NBC 2016 Part 8 Section 2 — electrical installations.
• CEA Regulations 2010 — statutory framework.
• State Fire Service Acts and Rules — regulatory requirement for HFFR in public buildings.
• BS 7211 — UK low-smoke halogen-free cable standard (international comparison).

1. Project specifies 'FR' cable when HFFR is mandated. State Fire Service rejects design; project delay. For schools / hospitals / hotels / public assembly, HFFR (IS 17048) is mandatory. 2. HFFR cable used in dry industrial premises (cost-no-object overspec). PVC FR or XLPE FRLS adequate for routine industrial; HFFR cost premium without commensurate benefit. 3. Fire-rated cable confused with HFFR. Fire-rated cable (per IS 17047) maintains circuit integrity during fire — different concept; both required for some critical applications (fire pump, fire alarm). 4. Cable termination not done with HFFR-compatible accessories. Joints / glands using PVC accessories on HFFR cable; weakest-link defeats purpose. Use HFFR-compatible cable accessories. 5. No batch test certificate. Manufacturer-stated 'HFFR' may not actually be tested per IS 17048; demand certificate. 6. HFFR cable used outdoor without UV-stabilised outer sheath. Outdoor-grade HFFR sheath has UV stabiliser; indoor-grade doesn't. Verify outer sheath grade. 7. Cable storage in damp / hot conditions. Insulation degrades; longer-term issues. Store dry, cool, FIFO. 8. Bending radius violated. < 6 × cable diameter for installation; cable insulation cracks. Per supplier installation procedure. 9. Ground temperature de-rating ignored on buried cable. 30 °C ambient assumption may not hold; reduce ampacity for actual ground temperature. 10. Mixed cable types in same conduit / cable tray. PVC + HFFR + fire-rated; in fire, PVC burns and degrades others. Use single-grade route per fire compartment. 11. No fire-stop at compartment boundary penetrations. Cable tray penetrating fire-rated wall = fire bypasses compartmentation. Fire-stop putty + barrier. 12. Distribution board not labelled. Maintenance / emergency identification difficult. Mandatory labelling per IS 1646 + IS 732. 13. HFFR cable marketed without BIS licence. Demand BIS / ISI mark + IS 17048 reference.

Cable grade hierarchy (in order of fire-safety):

| Grade | Spec | Use | |---|---|---| | PVC general | IS 1554 Part 1 | Industrial / non-critical | | PVC FR (Flame Retardant) | IS 1554 Part 1 | Residential, commercial general | | PVC FRLS (FR Low Smoke) | IS 1554 Part 1 | Multi-storey commercial / residential | | XLPE FR | IS 7098 Part 1 | Industrial, higher temperature | | XLPE FRLS | IS 7098 Part 1 | High-rise commercial / residential | | FR-LSH (Low Smoke Halogen-free) | IS 7098 / IS 1554 with halogen-free formulation | Hotels, schools, hospitals | | HFFR / LSZH (this code, IS 17048) | IS 17048 | Critical: hospitals, metros, data centres, public assembly | | Fire-rated (circuit integrity) | IS 17047 | Fire pump, fire alarm, lift, emergency lighting (must function during fire) |

Selection cascade per project:

1. Project category (NBC 2016 Part 4) — residential / commercial / institutional / industrial / hazardous. 2. State Fire Service requirements — local jurisdiction may mandate higher grade. 3. Insurance + financing — banks / insurers may demand HFFR for high-value projects. 4. Cable specification per zone: - Public common areas (lobbies, lifts, escape routes): HFFR (IS 17048) - Server rooms / data centres: HFFR + fire-rated for critical circuits - Industrial process areas: PVC FR or XLPE FRLS - Residential apartments: PVC FRLS 5. Design + BOQ — specify per zone, total cable demand, conductor sizes. 6. Procurement — BIS-licensed manufacturer, batch test certificate. 7. Installation — per IS 732:1989 practices; bending radius, fire-stop at penetrations. 8. Inspection + commissioning — insulation resistance, earth continuity, polarity, residual current device test.

IS 17048 represents the modern best-practice for fire-safety cable in critical installations. As Indian construction increasingly emphasises occupant safety + life safety, HFFR adoption is growing rapidly — particularly in metro / smart-city projects, hospital expansion, and data centre development.