The safety lock of PKT is used for protection of power transformers, voltage transformers cable and air-lines. Most often safety locks of PKT are applied when mounting in integral transformer substations. Today similar safety locks are issued a large number of producers, however for the purpose of decrease in costs of production, they are made on own TU, but not in accordance with GOST. Initially safety locks of PKT were issued the Elektrozashchita enterprises (St. Petersburg) and IZVA (settlement of Idritsa), however these enterprises did not manage to keep the prices capable to compete with the safety locks which are made not in accordance with GOST. High-voltage safety locks are applied to protection of the panel board equipment which price is much higher than the cost of safety locks therefore you should not save on them.
PKT safety locks having a quartz filler are current-limiting. PKT safety locks with quartz sand make shutdown of a short-circuit current by means of an intensive deionization of an arch which arises in the place where the fusible insert, between filler particles lies. Indication of operation of the boss in safety locks of PKT 101, PKT 102, PKT 103 and PKT 104 is carried out by means of the index of operation which after burn-out of a nikhromovy wire at influence of a spring moves forward outside.
Safety locks of PKT 101, PKT 102, PKT 103, PKT 104 are sets which consist of the following elements and are delivered knocked-down:
* the boss (the replaced element) MONDAY, FRIDAY 1.1, FRIDAY 1.2, FRIDAY 1.3, FRIDAY of 1.4 - 1 pieces.
* contact (is also called: a sponge, tweezers) K01, K02, K03, K04 – 2 pieces.
* a base insulator of IO-6-3,75, IO-10-3,75, ONS-10-300 – 2 pieces (insulators are established on a special socle or directly on members of the distributing device).
In networks which tension is less than rated voltage of a safety lock use of safety locks of PKT is not allowed. Marking of the boss is applied on the middle of a porcelain tube, marking of an insulator is applied on a side surface, marking of contacts is applied on a surface of a steel level of contact. Marking is carried out by means of application labels.
Interpretation of a symbol of safety locks of PKT 101, PKT 102, PKT 103 and PKT 104 is given as an example for a safety lock of PKT 101-10-16-20 U1:
* P - a safety lock -
* K - with a quartz filler -
* T - for power transformers -
* 1 - single-pole, with the index of operation -
* 01 - a contact design -
* 10 - rated voltage in kilovolts -
* 16 - rated current of a safety lock in amperes -
* 20 - rated current of shutdown in kiloamperakh-
* U - climatic execution -
* 1 - category of placement.