Protection or changing of GSGB Fuse(HRC)

A combination of circuit breaker in the upstream and fuse in the downstream can help.

Molded Case Circuit Breakers (MCCBs) provides over current protection and disconnecting means.

MCCBs use a design featuring high-speed "blow-open" action that results in superior performance when high level fault currents produce extraordinary electromechanical forces. These circuit breakers also feature advanced arc extinguishing technology.

Current limiting fuses are available in both time-delay and fast-acting modes. Current grading is possible such that the breaker first trips.

Dear Nvmani,

Thanks for the idea.

Suppose I insert a 350A of GSGB FUse BS88-1988 IEC 269-4 100kA 660V AC, what type and mfg of MCCB is available to get good discrimination of protection?

Another question, as we know that there's a surge protection device (SPD) that mainly corporate with the spike of voltage fluctuations, when load side withstand voltage is 1.2kV, so no matter what the supply voltage will be as long as in the range of SPD, the load side voltage will be maintain at 1.2kV max. so the equipment is safe from voltage spike.

Is there any other similiar device that corporate with withstand current?

Thanks you for your time, sir.

Regards.

Dear nvmani,

I just found the time/current characteristic of GSGB Fuse (HRC Fuse Link) Ultra high speed, refer to the graphic, for GSGB85 its pre-arching time for 3kA propective current is much less than 5ms (0.005 seconds), and its total operation time maximum 20ms.

Could you please give me the reference of MCCB type and manufacturer which have breaking time less than 5ms or 20ms? as far I know, the operation time of MCCB when fault occur is in the range of unit time in second.

thanks in advance.

Best Regards.

Hi,

can i use a 6Amp,400ac, HRC fuse for DC protection of 6Amp?