Composite post insulator 3FT7, HTV silicone housing, 150 mm ECR core, SCL 150 kNm, 1.0 – 5.5 m, AC/DC
3FT7
- Largest core-diameter class of the 3FT family at 150 mm (5.9") — top mechanical rating of the range at SCL 150 kNm, for station post and line post applications on both AC and DC systems
- HTV silicone housing applied by multi-shot injection molding on an ECR fiberglass core; overmolded end fittings seal the triple point against moisture ingress
- Lightning withstand > 3050 kV at maximum length; creepage factor 4.2 shed profile per IEC 60815-3 (AC) / IEC 60815-4 (DC)
- Single-unit length 1.0 – 5.5 m in 12.5 mm increments, stackable; end fitting: through-holes flange 8x D18 D254 (only flange style listed for this type)
- Designed and tested to IEC 61952 / IEC 62231 and ANSI C29.17 / C29.19; optional Factory Acceptance Tests (FAT) in Asia and Europe
Busbar support in HV substationsSupport insulator below HV equipmentInclined and braced line postJumper supportInterface and interline spacersComposite insulator crossarm (CICA)
Sign in to see your price, availability and framework terms for 3FT7.
Horizon-3 pattern: this exact page gains commerce powers on sign-in — the URL never changes.
SIMULATED · ASK-AN-EXPERT PILOT DEMO
Ask an expert about 3FT7
15 minutes with the right arresters & insulators specialist — question in, booked call out. No email archaeology.
Checking availability…
Specifications
Main
| Product family | 3FT7 |
| Product type | Composite post insulator (station post / line post) |
| Series | 3FT composite post insulators, core classes 3FT2 – 3FT7 |
| Current type | AC and DC |
Ratings
| Core diameter | 150 mm (5.9") |
| Specified Mechanical Load (SCL) | 150 kNm (equivalent to ceramic breaking load) |
| Maximum Design Cantilever Load (MDCL) | 75 kNm |
| Length | 1.0 – 5.5 m single unit, in 12.5 mm increments; stackable |
| Lightning withstand | > 3050 kV |
| Creepage factor (creepage/arcing) | 4.2 |
| System voltage validation | 3FT family validated by electrical-field simulations up to 800 kV system voltage; larger corona rings required at higher system voltages |
Mechanical & environment
| Housing | HTV silicone rubber, multi-shot injection molded — aging-resistant, hydrophobic, UV-resistant |
| Core | ECR fiberglass rod (electrical and corrosion resistant) |
| End fittings | Through-holes flange 8x D18 D254 |
| Adhesion system | Extensively tested primer system bonding silicone housing, fiberglass rod and end fittings, with continuous monitoring and strict quality control in production |
Standards & certifications
| Line post | IEC 61952 · ANSI C29.17 |
| Station post | IEC 62231 · ANSI C29.19 |
| Shed profile | IEC 60815-3 (AC) · IEC 60815-4 (DC) |
| Testing | Fully tested to IEC and ANSI standards; optional Factory Acceptance Test (FAT) in Asia and Europe |
Documents & downloads
Flyer 3FT composite post insulators — Engineered for extreme performance
Datasheet 3FT7 type-specific datasheet — available on request
Ordered designations
Representative orderable type designations of this family — searchable via the catalog search.
Related products
3FH 
3FL2
Composite hollow-core insulators 3FH — apparatus housings for breakers, bushings and instrument transformers; detailed ratings on request
Apparatus housings · Composite hollow-core · Ratings on request Datasheet · Dimensions ↓ 3FL-HVDCHVDC converter tension insulators, 3FL composite long-rod platform, one-piece HTV silicone housing on ECR glass FRP rod
HVDC converter tension duty · 3FL composite long-rod platform · Silicone housing Datasheet · Dimensions ↓ 3FL2