Find a phase sequence protector in which the relay does not activate when power is applied
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Ordinary phase sequence protectors on the market have their relays engage when power is supplied, indicating that the power supply is normal; when there is a missing phase or phase imbalance, the relay disconnects, signaling a fault. The relay also stays disconnected when there is no three-phase power supply. What I need now is a phase sequence protector whose state remains the same whether the power supply is normal or not, with only a difference in state when there is a missing phase or a broken connection. Ideally, the relay should stay engaged when the three-phase power supply is normal or when there is no power at all (an auxiliary power source can be used); it should only disconnect in cases of missing phases or broken connections. Has anyone used such a voltage detector or phase sequence protector?
It seems the state you’re looking for isn’t common
I’m curious – if you have no electricity left, where does the electricity come from to enable it to attract things?
You can weld a logic circuit board by yourself to output a closed signal when all the signals from the three mutual inductors are present, or a disconnected signal when one of them is missing; it should be available on Taobao
You can weld a logic circuit board by yourself to output a closed signal when all the signals from the three mutual inductors are present, or a disconnected signal when one of them is missing; it should be available on Taobao
Or you can use two sets of relays, one set with three relays, for a total of six relays. The first group consists of three normally open switches connected in series, the second group consists of three normally closed switches connected in series, and then these two groups are connected in parallel