The automatic switches are designed to conduct current in the normal mode and to protect against overloads of the mains and to load by automatic switching-off of the current as a result of a long-term overload and against short-circuit current. The switches are made of thermostable materials possessing high insulation strength (at least 2500 V), high insulation resistance (at least 50 МΩ), are fire-safe.
The operating temperature is from minus 60 ºС to 55 ºС.
The switches are made in the three-pole or two-pole version with electromagnetic and thermal maximum-current tripping devices or without thermal tripping devices, with such additional assemblies: an independent tripping device, additional normally closed and normally open contacts
Availability of the additional assemblies and thermal tripping devices is determined by the order.
The nominal values of the current are stated in the order for the electromagnetic tripping devices: 800, 1200, 1600, 2000 А of alternating current, for the thermal tripping devices: 31.5, 40, 50, 63, 80, 100, 125, 160, 200, 250 А of alternating current.
The independent tripping device provides disconnection of the load when a voltage of 110, 127, 220, 240 or 380 V of alternating current or 110, 220 V of direct current is applied in 0.04 sec, maximum. The short-term power consumption is 300 VА.
The additional free contacts operating for closing or opening of the circuit in synchronism with the main contacts allow to switch a current up to 4 А with a voltage up to 380 V.
The switch provides another switching-on at once after quick switching-off, in 2 min after operation of the electromagnetic tripping device and in 3 min after operation of the thermal tripping device.
The voltage drop at the switch does not exceed 75 mV.
The switch design allows:
- to monitor serviceability of the maximum-current tripping devices with the TEST button;
- to connect current conductors in the shape of a cable with a section from 6 to 185 mm2, a bus from 1.5х14 to 6х25 mm in case of a front connection. The material of the conductors is copper or aluminium;
- to connect to the current-carrying buses with the help of the mounting set in case of a rear connection. The connection version is stated in the order;
- to ensure the fire safety requirements thanks to the use of an efficient design of arc, spark extinction as well as special plastics for the body;
- to ensure high wear resistance – at least 16000 switchings-on/switchings-off at the expense of separated disposition of the switching-off and control mechanisms from the spark and arc formation zone.
Thanks to the use of a bridge design of the moving contact, the switch ensures the max value of the utmost switching-off capability of 75 kА with a voltage of 380 V and 18 kА with a voltage of 660 V, this exceeds by 5–20 % the switches made by the famous companies – "Контрактор" Ulyanovsk – ВА04-36, ВА06-36; "ДЗНВА" Divnogorsk – ВА57-31, ВА57-35; KONCAR Croatia – series ВМ; "FEDERAL" Turkey – series 160, 250; FELTEN and GUILLEUME – series МВ-АА, etc.
The switches have been certified in Ukraine and Russia.