Coil end lead cable is the flexible connection made directly and permanently to a winding or other component inside electrical apparatus — motor and generator coil tails, transformer leads, switchgear and panel wiring. BS 6195 covers the rubber and silicone rubber insulated cables used for this purpose, where the cable has to tolerate the heat of the machine, mechanical vibration and contact with lubricants. Type designations within the standard run from low voltage panel wiring grades up to medium voltage machine leads.
Key applications
- Motor and generator coil end connections
- Transformer winding leads
- Electrical machine and panel internal wiring
- Switchgear internal connections
- Equipment wiring where oil and lubricant contact is likely
- An alternative to tri-rated cable in machinery panels
Features and benefits
- Rubber insulation withstands machine operating temperatures that would soften PVC
- CSP sheath resists penetration by lubricating oils and greases
- Class 5 flexible copper suits tight routing inside machines and panels
- Available across a wide voltage range for both LV and MV machines
- Flame retardant construction
Specification notes and limitations
Coil end lead cable is intended for use inside apparatus, connected permanently to a winding — it is not a general purpose flexible cable, not a trailing cable and not suitable for fixed building wiring or burial. The type designation determines the voltage rating, and the types are not interchangeable; fitting a 600/1000 V grade where an 11 kV machine lead is specified is a serious error. Ratings assume the cable is in free air inside the machine: enclosed, bunched or resin-encapsulated leads need derating, and the published current rating is not valid where the lead is buried in a winding. Respect the bending radius at the coil tail, where vibration and thermal cycling concentrate, and keep leads clear of rotating parts and hot stator surfaces.
