Products
Indoor SF6 Circuit Breaker
Key Features
MH4 type Indoor SF6 circuit breaker manufactured by Naten in China. It uses sulphur hexafluoride gas (SF6) to extinguish the electric arc and as the insulating medium.
MH4 type Indoor SF6 circuit breaker
-Summary-
Naten® Electric strives to bring our customers the latest technology and competitive pricing and best HM4 medium voltage circuit-breakers use sulphur hexafluoride gas (SF6) to extinguish the electric arc and as the insulating medium. Breaking in SF6 gas takes place without any arc chopping and without generation of overvoltages. These characteristics ensure long electrical life of the circuit-breaker and limited dynamic, dielectric and thermal stresses on the installation.
The circuit-breaker poles, which make up the breaking part, are systems with lifelong sealed pressure (IEC 62271- 100 and CEI 17-1 Stand- ards) and are maintenance-free.
The REH type mechanical operating mechanism, with stored energy has free release and allows opening and closing operations independently of the operator’s actions.
The operating mechanism and the poles are fixed to the metal structure which also acts as a support for the kinetics for operating the moving contacts. Circuit-breakers in the withdrawable version are fitted with a truck to allow racking in and racking out of the switchgear or enclosure.
The light and compact structure of the circuit-breaker ensures great sturdiness and excellent mechanical reliability.
Offering
Autopuffer breaking technique
Electric are extinction without chopped current
No restriking after breaking
Rapid recovery of the dielectric properties of the means of extinction
Withstand insulation voltage even at zero relative pressure(*)
Breaking up to 30% of the rated breaking capacity even at zero relative pressure(*)
Sealed for life poles
Test for checking gas tightness carried out three times on each piece of apparatus
Compact dimensions
Fixed and withdrawable version
Stored energy operating mechanism with anti-pumping device as standard common to the whole circuit-breaker series
Mechanical safety locks against incorrect operations
Simple personalisation thanks to a com-plete range of accessories
Maintenance-free
SF6 gas pressure control device (on request).
Fields of application
HM4 circuit-breakers are used in power distribution to control and protect lines, transformer and distribution substations, motors, transformers, capacitor banks, etc.
Thanks to the SF6 autopuffer breaking technique, the HM4 circuit-breakers do not generate operating overvoltages, and are therefore also highly suitable for retrofitting, upgrading and enlarging older installations where the motor,cable, etc. insulating materials may be particularly sensitive to dielectric stresses.
Breaking technique
The breaking technique of HD4 circuit-breakers is based on compression and self-blast techniques to obtain top performances at all service current values, with minimum arc times, gradual arc extinction without chopping, and no restriking or operating overvoltages.
The HM4 series brings to medium voltage the advantages of the “autopuffer” breaking technique already used in high voltage.