These devices are used for prevention of exceeding of the most admissible current intensity which reason can be a short circuit or an overload. Safety locks of the PPN series are the convenient and economical decision for different difficult electric devices and networks, in particular, for distribution and managing cabinets, transformer substations and input distributing devices. As a basic element, in safety locks of PPN the fusible inserts belonging to the category gG are used. Protective devices of safety locks of PPN are more technically modern, and have succeeded the previous generation of safety locks of the MONDAY series. In case of replacement of such safety locks newer, loss of power owing to use of protective devices in a network will decrease almost on a third. In addition It should be noted more compact sizes allowing to optimize chassis space and strong material of production thanks to which operation term increases.
The most actual these devices of protection against increase of current intensity are if you wish to save money not to the detriment of quality and reliability. Domestic safety locks of PPN is a full replacement to expensive foreign analogs. Moreover, these safety devices can be used both in Russian, and in the import equipment. At identical technical datas the price of safety locks of PPN is almost twice lower. Such difference is explained by an exception of big costs of transportation, storage and the expenses accompanying import.
Design features of safety locks of PPN
The main members of this device – the holder who is made of special plastic or the ceramic material covered with glaze and a fusible insert for which production phosphorous bronze and quartz sand of high-quality cleaning is used. Holders and contacts of a fusible insert are made of special electrotechnical copper and have a covering from a tin-bismuth alloy. Indication of operation is carried out by means of a special retractable rod by means of which it is possible to define visually, protection has worked or not.
Technical datas of a safety lock of PPN:
Rated operating voltage: at alternating current of 50 and 60 Hertz – 380 and 500 Volts, at a direct current – 220 and 440 Volts.
Breaking capacity: 50 kA
Climatic standards: UHL2, UHL3, T3
Operating temperature range: from - 40 °C to + 60 °C
Degree of protection against external influences: IP20
Standards of admissible mechanical influence: M7, GOST 17516 M25
Situation concerning sea level: not above, than 2 kilometers above sea level
Working situation: horizontal or vertical
Compliance to normative documents: MEK 269-2D, MEK 269-2, MEK 269-1
Interpretation of marking of a type of PPN-HH-HH-HHHPPN (one after another from left to right):
XX – rated current (39 – 630 And, 37 – 400 And, 35 – 250 And, 33 – 160 And)
X – a way of fastening (7 – by means of completing device conductors, 5 – by means of the insulating basis of the additional device, 2 – by means of own insulating basis)
X – type of the indicator of operation of a safety lock (3 – with the operation indicator, but without free contacts, without quickly, 1 – with the operation indicator, with free contacts, 0 – the indicator is absent, is not present quickly, there are no free contacts)
X – degree of protection of a safety lock against external environmental activities
XX – category of placement and a climatic modification