F650. Impulse current of DC power supply consumption.

[VicZaDum]

Could you help me. The question is about the impulse current of DC power supply consumption of the F650 relays in certain circumstances.
I mean the inrush of direct current during the moment of voltage supply restoration after interruption time no longer than 1 minute. It causes a trip of the up stream circuit breaker in the supply circuit.
On GEindustrial.com/Multlin web site I couldn’t find anything about this phenomenon.
I have checked this circuit breaker; the instantaneous magnetic tripping current pickup was equal to 8 amperes. It occurs only in a supply circuit of quite powerful power supply, i.e. battery 220V, 70 ampere-hours (quite low impedance). If I use a less powerful power supply e.g. the laboratory source of rectified current 220V; 180 watts, this kind of trip does not occur. I measured long consumption of the F650 relays, it was less than 0.2 amperes.
The relays perform all theirs functions properly.
What minimum pickup current of instantaneous magnetic element of the circuit breaker could you recommend to select in supply circuit of the F650 at battery 220V?
Thank you.

 

[slavag]

Hi.
My practic for all type of digital relay digital relay : MCB with K4 or K6 curve.
Regards.
Slava

 

[dpc]

I use fuses for dc control circuits. But 8 amps inrush doesn't sound that high. You probably need a much bigger breaker.

On dc control circuits, the breaker or fuse is really only there for short circuit protection. It's pretty common to see 30 A breakers on dc control circuits with load of only 1 or 2 amps.

 

[slavag]

Hi.
for K4 (that mean 4A nom) curve, inst. current is
around 40-50A.
We used fuses only on battery output.
Regards.
Slava