Ceramic Cross-Arm Insulator

The ceramic cross-arm insulator is suitable for power lines with voltage under 35kv and frequency under 100Hz and the alitude is under 1000m. It is used as insulation and supporting. The ambient temperature is -40 º C~+40 º C.
It can be vertically and horizontally installed.

Model Decription:
JB/T 8179-1999:
S---ceramic cross-arm insulator
The figure followed "-"is rated voltage value, KV
The figure followed "/" is rated bent failure load, kN.

GB/T 21206-2007
RA— Pillar insulator as cross-arm;
The figure followed RA is rated bent failure load, kN.
The letter E or J refers to the external adhesive or internal adhesive modes of accessory metal fittings;
Then the letter T, C, H, respectively refers to top binding, top clip for vertical installation or top clip for horizontal installation;
Number followed "-" is withstand voltage of full wave lightning impulse, kV;
The N and L refers to standard creepage distance and longer creepage distance.


Compared with electrical and mechanical properties of ordinary line insulator with the same voltage grade, those of the ceramic crossarm insulator have the following features:
(1) The insulation distance and the creepage distance of the ceramic crossarm insulator is longer. The flashover voltage of 50% full wave impulse and the dry flashover and wet power frequency is higher;
(2) The ceramic body of ceramic crossarm is comparatively long. The mechanical bending strength is low. Considering of safety coefficient, maximum allowable load generally are smaller than normal line insulator of the same voltage grade, so the ceramic crossarm is not suitable for big conductor with cross section and line span.

Compared with ordinary insulator set up distribution circuit, the ceramic crossarm distribution circuit have the following advantages
(1) adopt rotating structure, when cables break, imbalance of conductor tension can make the ceramic crossarm rotate, effectively mitigate the expansion of the break accident;
(2) the line insulation level and lightning resisting level is higher, the accident rate is low;
(3) the ceramic body are easy to be cleaned by wind and rain wash, having good self-cleaning, without breakdown. There will less small amount of replacement and maintenance;
(4) easy construction and installation. It can raise the distance of 0.3— 2.2m between the cables and the ground when at the height of the tower is the same.
(5) save raw materials such as steel, wood, and can reduce the cost of single-base tower up to 10% ~ 50%.