What is porcelain line post insulator?
 
Porcelain Line Post insulators are one main type of the highest quality porcelain insulators. They are manufactured from wet process porcelain, giving them the ability to shed water and dirt. This allows for little-to-no maintenance. Line post insulators are designed to provide rigid support of conducting cable while offering the maximum resistance to damage from electrical or mechanical events. Line post insulators were produced with solid core which decides line post insulators are puncture proof type. This not like pin insulators, pin insulators was puntured type.
Horizontal and gain-base line post insulators are often used in applications to avoid the need to install a crossarm on the pole.
The clamp style units include a galvanized metal head which accepts standard trunnion style line clamps.
 
ANSI C29.7 standard insulators type:

  • ANSI 57-1 series: ANSI 57-1, ANSI 57-2, ANSI 57-3, ANSI 57-4, ANSI 57-5
  • ANSI 57-11 series: ANSI 57-11, ANSI 57-12, ANSI 57-13, ANSI 57-14, ANSI 57-15
  • ANSI 57-21 series: ANSI 57-21, ANSI 57-22, ANSI 57-23, ANSI 57-24, ANSI 57-25
  • ANSI 57-31 series: ANSI 57-31, ANSI 57-32, ANSI 57-33, ANSI 57-34, ANSI 57-35
Neck Designation and Dimensions:

Designation Letter Diameter
(mm)
Groove Height Relation ship as applicable
(mm)
Minimum Maximum
A 44 - -
C 57 14.3 22.2
F 73 14.3 22.2
J 89 6.4 15.9
K 105 6.4 15.9
N 156 14.3 22.2
Porcelain Line Post Insulator Picture:
ANSI 57-1 Series Porcelain Line Post Insulator types:

Type No. ANSI 57-1 ANSI 57-2 ANSI 57-3 ANSI 57-4 ANSI 57-5
Creepage Distance - (mm) 356 559 737 1016 1143
Dry Arcing Distance - (mm) 165 241 311 368 438
Cantilever Failing Load - (kN) 12.5 12.5 12.5 12.5 12.5
Wet Flashover Voltage - (kV) 50 70 95 110 130
Dry Flashover Voltage - (kV) 70 100 125 140 160
Critical impulse flashover Pos. - (kV) 120 160 200 230 265
Critical impulse flashover Neg. - (kV) 155 205 260 340 380
Test Voltage to Ground - (kV) 15 22 30 44 44
Max.RIV at 1000kHz - (µV) 100 100 200 200 200

ANSI 57-11 Series Porcelain Line Post Insulator types:

Type No. ANSI 57-11 ANSI 57-12 ANSI 57-13 ANSI 57-14 ANSI 57-15
Creepage Distance - (mm) 356 559 737 1016 1143
Dry Arcing Distance - (mm) 165 241 311 368 438
Cantilever Failing Load - (kN) 12.5 12.5 12.5 12.5 12.5
Wet Flashover Voltage - (kV) 50 70 95 110 130
Dry Flashover Voltage - (kV) 70 100 125 140 160
Critical impulse flashover Pos. - (kV) 120 160 200 230 265
Critical impulse flashover Neg. - (kV) 155 205 260 340 380
Test Voltage to Ground - (kV) 15 22 30 44 44
Max.RIV at 1000kHz - (µV) 100 100 200 200 200

ANSI 57-21 Series Porcelain Line Post Insulator types:

Type No. ANSI 57-21 ANSI 57-22 ANSI 57-23 ANSI 57-24 ANSI 57-25
Creepage Distance - (mm) 356 559 737 1016 1143
Dry Arcing Distance - (mm) 165 241 311 368 438
Cantilever Failing Load - (kN) 12.5 12.5 12.5 12.5 12.5
Wet Flashover Voltage - (kV) 50 70 95 110 130
Dry Flashover Voltage - (kV) 70 100 125 140 160
Critical impulse flashover Pos. - (kV) 120 160 200 230 265
Critical impulse flashover Neg. - (kV) 155 205 260 340 380
Test Voltage to Ground - (kV) 15 22 30 44 44
Max.RIV at 1000kHz - (µV) 100 100 200 200 200

ANSI 57-31 Series Porcelain Line Post Insulator types:

Type No. ANSI 57-31 ANSI 57-32 ANSI 57-33 ANSI 57-34 ANSI 57-35
Creepage Distance - (mm) 356 559 737 1016 1143
Dry Arcing Distance - (mm) 165 241 311 368 438
Cantilever Failing Load - (kN) 12.5 12.5 12.5 12.5 12.5
Wet Flashover Voltage - (kV) 50 70 95 110 130
Dry Flashover Voltage - (kV) 70 100 125 140 160
Critical impulse flashover Pos. - (kV) 120 160 200 230 265
Critical impulse flashover Neg. - (kV) 155 205 260 340 380
Test Voltage to Ground - (kV) 15 22 30 44 44
Max.RIV at 1000kHz - (µV) 100 100 200 200 200