GLASS INSULATORS 70kN
The HV line suspension insulators are used for insulating and fixing wires and lightning-arrester's cables of overhead power trans-
mission lines, in devices of power stations and substations for high voltages of altering current and direct current with frequency up
to 100 Hz, also within a temperature range of +50°C and -60°C.The insulators are made of an insulating element, a cap and a pin.
When suspension insulators are used on HV power transmission lines, they are usually connected in series to form a string.
The insulators are hinged between by introducing insulator’s pin head into following insulator’s top part of the cap (socket con-
nector). To avoid a sudden uncoupling of a string, the pin is locked in the cap slot. The number of insulators per string depends on
the line voltage, material of supporting structures, type of insulators and local operating conditions.
Resistant insulators are used on the transmission lines in the regions with polluted atmospheres. These insulators had an increased
creepage distance.
IEC standard
Profile | Standard | Anti-pollution | Spherical |
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Hanford reference | F70/127 | F70/146 | F70P/127 | F70P/146 | F70PP/146 | F70R/146 |
Class IEC-60305 | U 70 BS | U 70 BL | U 70 BS | U 70 BL | U 70 BLP | U 70 BLP |
Minimum mechanical failing load (kN) | 70 | 70 | 70 | 70 | 70 | 70 |
Dimensional data | Spacing (S) mm | 127 | 146 | 127 | 146 | 146 | 146 |
Diameter (D) mm | 255 | 255 | 255 | 255 | 280 | 255 |
Creepage Distance (mm) | 320 | 320 | 390 | 390 | 445 | 300 |
Standard coupling IEC-60120 | 16A | 16A | 16A | 16A | 16A | 16A |
Electrical ratings | Power frequency withstand voltage |
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Dry (kV) | 70 | 70 | 80 | 80 | 85 | 80 |
Wet (kV) | 40 | 40 | 45 | 45 | 50 | 45 |
Dry lightning impulse withstand voltage (kV) | 100 | 100 | 110 | 110 | 125 | 95 |
Puncture voltage in oil (kV) | 130 | 130 | 130 | 130 | 130 | 130 |
Packing information | Approx. unit net weight (kg) | 3.4 | 3.4 | 4.6 | 4.6 | 5.6 | 4.2 |
No. of insulators wooden crate | 6 | 6 | 6 | 6 | 6 | 6 |
Type Tests and Special Tests
For each type of toughened glass insulator, there are available type test reports and special test reports in accordance with applicable
standards. Our laboratory technicians also collaborate with these institutions in order to perform said tests on both individual
insulators and complete strings.
These reports serve to demonstrate, once again, the quality and reliability of our products. They are regularly updated and are available
to any client who wishes to consult them.
Suspension insulator components
Suspension insulators consist of the following elements:
One dielectric made of toughened glass with the appropriate properties and shape for the environmental conditions in which it must
function.
One hot-dip galvanized nodular or ductile malleable cast iron cap.
One hot-dip galvanized forged steel pin.
The cap and pin are assembled on the glass piece using aluminous cement with the appropriate properties to withstand the thermo-
mechanical efforts.
Lastly, the insulator cap has a stainless steel or phosphor bronze locking device (split pin) which secures the coupling of the units.
Similarly, the pins may be protected using an anti-corrosion zinc sleeve (sacrificial anode), when requested.
This zinc sleeve is strongly recommended for insulators which are going to be used in lines with heavy pollution.
Insulators for direct current lines are always supplied with this sleeve.
