Insulating gas

Insulating gas, necessary for the first priming, must be put together with a distributive device, together with a connecting tube and accessories.

Insulatig gas, tucked in GIS, must conform to the proper requirements of IEC.

At handing over in exploitation of GIS, the point of dew of insulating gas must be measured and documented.

For transporting components can be filled nitrogen and serviced insulating gas in place.

All gas seals must be projected so that a norm of loss of IG (insulating gas) was on an absolute minimum. The possible loss of IG must not exceed 0.5% in a year for mounted GIS.

All gas seals must be with protecting of seals from dirt and corrosion and must be central type.

The device of monitoring of closeness of IG with temperature indemnification must be set on every IG component. Any connection of pipes between different gas compartments and centralized measuring device is shut out.

A device must provide the permanent and automatic monitoring of closeness of IG.

The system of monitoring of IG must have two emergency setpoints: -before warning, when the closeness of IG approaches a low level; -level of alarm, when the closeness of IG arrives at the minimum level of isolation and blocking of wearing-out of switch is initiated.

The device of automatic depressurization must be set on every IG component as a preventive measure against the break of construction.

The devices of automatic depressurization must be placed so that to guarantee safety of personnel in the case of unexpected depressurization gas.

SHELL AND TIRES

Every shell filled under constraint must be projected and made in accordance with a standard and must be based on a project temperature and project pressure as it is certain in IEC 62271-203.

For shells the alloy of aluminium must be exceptionally used, to prevent external and internal corrosion, and also necessity of the periodic cleaning and painting.

Shells must be projected so that to eliminate, as far as it is possible, all influences are the fields, created normal and by the current of s.g. The losses of energy in the system must be taken to to minimum and pointed tensions on shells must not exceed the possible redistribution of safety. A supplier must give accompanying calculations on the pointed tension and losses.

Project calculations or reports of verification tests, demonstrating durability of shell at project pressure and project temperature must be given.

Increase of temperature of current wire parts must be limited values, marked in IEC 62271-1, at a nominal current and climatic terms on a ground.

The explorers of tires must be made from a copper or alloy of aluminium.

The proper measures must be undertaken for indemnification of temperature expansion of explorers and differential temperature expansion between explorers and shells.

Where it is necessary, the metallic scrapes of silphon type must be well-to-do with the managed pull.

Compensating joints, flexible connections and managed fastenings, must be foreseen, to compensate possible production and construction admittances in the proper equipment, which GIS it can be connected to.

All entablature, necessary for setting of equipment of GIS, must be put, including concomitant parts.

To all equipment GIS must be carefully thought out access. To all valves of priming access must be well-to-do through a light cart.

After a production, all metallic parts of construction must be treated the hot zincking. All assembling connections must be bolted. Welding in place of setting is shut out.

For screw-bolts and nuts must be used not corrosion metal.

For editing of cells to the floor it is recommended to use wall screws. Organization of grounding of GIS must guarantee that foot-pace tension and tension of touch will be in safe values. The shells of GIS must be earthed so that there was an earthing contour round all feeding parts.

The wires of grounding must be counted on damages with the current of short circuit. Wires can be done from a copper or aluminum. The closets of local government and distributive boxes must be earthed a separate wire.

All troughings and shells of management cables must be connected to the tires of grounding of closet of management or distributive box. All metallic parts must be earthed.

CONTROL CLOSET

Every module of cell of distributive device must be supplied a management closet set either on the floor or mounted on a distributive device. A closet must be with the locked doors.

A closet must provide next basic functions:

- symbolic circuit;

- functions of management of distributive device;

- mode of local/remote management;

- local reflection and management;

- indication of position;

- notification about the decline of pressure of IG;

- built-in blocking of cell;

All chains managements and conclusions, connecting a distributive device with the closet of management of module cell, must be given a producer.

All cables of management must be screened.

All cables of management must be set and backfilled so that to limit the effect of the pointed tension at possible level.

A producer must give the special devices, necessary for normal exploitation of distributive device, such as:

- handle for a hand management isolating switch and ground knives;

- handle for the mechanism of switch;

- portable system of refuelling IG with accessories for priming.

Any special instruments, necessary only on the period of setting and putting into an operation must be delivered a producer and must remain the propert of producer after completion of setting and putting into an operation.

A producer is under an obligation to put the list of the recommended spare parts, on a term at least five years for normal exploitation.

SWITCHES

Every switch must contain one compression arc extinguishing chamber. It must use IG both for an isolation and for extinguishing of arc.

A mechanism of switch must be modern standard and reliable technology, without the use of some hydraulic mixtures or symbolic system.

A switch must have stocked energies, necessary for implementation of duty cycle about at losses of feed of the basic systems of energy supply.

A switch must be with the mechanism of the free unlinking and have protecting from discrepancy of phases.

Every switch must be supplied the local mechanical indicator of position of the closed type, together with the remote indicator of position on the module cell of management closet. Coloring and description of mechanical indicator must be following:

-there must be a meter of amount of operations on every switch;

-shells of switches must be the cast type.