Ogram
Newbie level 1
hvdc relay
Hello folks,
I'm having great troubles finding a suitable relay to act as a battery emergency disconnect switch. It should be able to disconnect 1kA (short time peak, avg. currents <400A) current rated at up to 450 volts dc, be able to do it for current flowing either way through the relay and preferably operate at 12 Vdc.
So far the closest thing I've found is the Kilovac EV250-series (link points to datasheet) relays and at the moment they are the only ones I've found which satisfy at least partially the conditions set.
Using two 250s parallel would greatly increase the number of switching times before welding would become a problem but this would in turn increase the cost of the system and introduce additional problems with the possibility that one of the relays would fail when triggered, in worst case scenario causing the other one also to fail and thus leading to possible damage to people/rest of the system.
I've been considering using SSRs instead of electromechanical relays but they tend to have a set of problems their own. GTO-thyristors can operate high power loads and their switching times are ideal when considering the use I've in mind but are they suitable as bidirectional DC switches or are they limited to AC-use only when dealing with high loads? Could someone elaborate?
Hello folks,
I'm having great troubles finding a suitable relay to act as a battery emergency disconnect switch. It should be able to disconnect 1kA (short time peak, avg. currents <400A) current rated at up to 450 volts dc, be able to do it for current flowing either way through the relay and preferably operate at 12 Vdc.
So far the closest thing I've found is the Kilovac EV250-series (link points to datasheet) relays and at the moment they are the only ones I've found which satisfy at least partially the conditions set.
Using two 250s parallel would greatly increase the number of switching times before welding would become a problem but this would in turn increase the cost of the system and introduce additional problems with the possibility that one of the relays would fail when triggered, in worst case scenario causing the other one also to fail and thus leading to possible damage to people/rest of the system.
I've been considering using SSRs instead of electromechanical relays but they tend to have a set of problems their own. GTO-thyristors can operate high power loads and their switching times are ideal when considering the use I've in mind but are they suitable as bidirectional DC switches or are they limited to AC-use only when dealing with high loads? Could someone elaborate?