Line Post Insulators
Porcelain line post insulators for distribution and sub-transmission lines. 160 mm shed diameter, 305 mm height, 400 mm creepage, 8 kN cantilever failing load.
The application
Why this family exists
A line post insulator turns the conductor support into a rigid cantilever: the conductor sits on top, the post takes the bending load, and the crossarm gets simpler. That geometry is why line posts are chosen for compact, narrow right-of-way construction and for lines where a pin insulator no longer has enough creepage.
What usually goes wrong
The load case that breaks a line post is not vertical weight, it is the sideways pull of wind on a long span plus conductor tension at an angle structure. Specify a post by its height and forget its cantilever rating and you find out the difference during the first storm season.
How we address it
The R12.5ET125N is published with an 8 kN cantilever failing load, which is the number to compare against the transverse load your span and angle actually produce. Its 400 mm creepage distance over a 305 mm height gives a creepage-to-height ratio suited to lines where pollution, not clearance, sets the design.
1 products in this family
Choose by the number that decides your design
| Line Post Insulator R12.5ET125N | Porcelain line post, 160 mm shed diameter, 305 mm high, 400 mm creepage, 8 kN cantilever. |
Answers
Line Post Insulators: common questions
What does the cantilever failing load mean in practice?
It is the transverse load, applied at the conductor groove, at which the post is expected to fail. Design loads should sit well below it with the safety factor your grid code specifies. The published figure for the R12.5ET125N is 8 kN.
Why choose a line post over a pin type insulator?
A line post gives more creepage and more mechanical stiffness in the same footprint, and it lets you mount the conductor above the post rather than tied to its side. On polluted or compact lines that is usually the deciding factor.
What is the creepage distance?
400 mm over a shed diameter of 160 mm and a height of 305 mm.
Can the post be supplied with a clamp top?
Tell us the conductor diameter and the fixing you intend to use and we will confirm what top assembly can be supplied with this body.
Send the line data, get a part number back
System voltage, pollution class, altitude, span and structure type. That is enough to select from this family with confidence.