Electrical systems are vulnerable to voltage spikes from lightning or switching surges surge arrestors take over in these high voltage situations they reroute power surges to earth to avert damage to the grid that would cause power failures and power cuts when lightning strikes surge arresters handle the fallout they divert the ensuing power surges to earth where they won’t cause damage at their core are discs the tactus switches they turn on and off to divert voltage spikes the discs are known as movs which is short for metal oxide varistors fiberglass strapping is looped onto.
Aluminium end caps to prepare the casings for the movs a spacer is placed on top of one of the end caps then numerous movs are placed on top equipping this arrestor to divert a kilovolt power surge more spacers are added to fill in any gaps the MOV stack must sit tight within the casing with the stack complete more fiberglass strapping is placed around the movs to complete the casing a set screw is used to compress the stack the set screw also pushes back the end caps which pulls the fiberglass strapping tighter the surge arrester assembly is then clamped between two mandrels a resin reinforced thread is wound around the fiberglass loop at one end the mandrels then spend the surge arrester module as a computer program dispenser whines the threat around it to strengthen it it creates gaps between the windings this will allow sparks and fumes to escape in the event of a power overload with the winding complete the end is cut.
Untucked under the last winding the module is then hung on a rack conveyer which takes it into a chamber here a tank filled with an adhesive promoting solution rises up and immerses the module this leaves a coating that will help a silicon rubber housing bond to the module later the hooks used to hang the module on the rack conveyor are removed and mandrels are placed at both ends to be used at a later stage of processing the module is placed between the rungs of a chain driven conveyor it takes it through an oven set at 150 degrees Celsius this cures the resin in the thread causing it to harden around the fiberglass strapping it also preheats the surge arrester module in preparation for the next process the molding of the outer housing using the mandrels to of the surge arrester modules are locked in a platform and slid under a mold press a lift takes it to the press the press injects silicon rubber into the mold and using pressure and heat.
Forms an insulating jacket around the arrestor modules the primer coating enhances the addition of the silicon rubber to the modules any unwanted bits of silicon rubber are clipped off the molded housing and the ends are cleaned up with a wire brush surge arresters come in a range of voltage ratings for different electrical systems the threaded bolt holes in one end are then lubricated and the holes are aligned with the ones on a terminal connector the connector is bolted to the surge arrester a bass is inserted on the other end this bass will allow the arrested to be mounted on the ground and send.
Excess voltage into the earth finally it’s time to test the surge arrester the engineer connects the electrodes to the terminal connector and to the base he runs different voltages of electricity through the arrestor and confirms that it discharges them it’s now ready to join the others on the grid forming a defense against lightning strikes power spikes and