rmartingt
Well Known Member
Now that I've settled on a general power architecture, I'm really starting to sit down and plan out my electrical system in detail. Part of that involves choosing switches. I have some aesthetic and functional preferences in mind*, but some technical requirements are driving me away from what I'd really like. I've been chasing my tail on the subject for quite a while so I figured I'd throw it out to the community.
The biggest obstacle I'm facing is current. I'm going to have an electrically-dependent engine, with power provided by a dedicated engine bus fed directly from each battery through diodes. The trouble has been finding switches with enough of a current rating to handle this feed. The nominal average draw for the engine bus is about 10A (which isn't that bad, and I wouldn't normally be cycling this switch under that kind of load), but peak loads could be higher and I'd like some margin on that given how critical this switch would be. I'm thinking 30A is a good target, based on Ross's description of an alternate feed for the engine electronics (30A ATO fuse and a heavy duty switch).
However, there are relatively few switches out there rated for 20A, and even fewer rated for 30A. Almost none of them have any kind of locking mechanism, and I'd really prefer to avoid the big red flip-up milspec switch cover for multiple reasons.
NKK makes a locking toggle rated for 20A: https://www.digikey.com/product-detail/en/nkk-switches/S6AL/360-1927-ND/1007005
The Carling Contura rockers can handle 20A as well, but I've only found one supplier in the US that carries a version that can lock in the "on" position: https://www.onlinecomponents.com/carling-technologies/vdd1hw611kv000-16995989.html
Past that, I haven't found any viable options that don't take up tons of panel space (e.g. marine battery disconnects).
I kicked about the idea of using automotive relays on these feeds, but I'd prefer to minimize components and connections on the critical items.
Any other suggestions or ideas?
Beyond this I have fuel pump and coil loads to worry about (also things I want with locks or guards), but those could use the same switch if necessary.
* If I could really have what I wanted, I'd use illuminated square pushbuttons like the Korry switches on airliners, with flip-up transparent guards on the critical switches but those are expensive... cheaper options exist but I'd have to drive everything with relays, and that's too complicated.
Failing that, I'd prefer the Carlings over the traditional toggle switches.
The biggest obstacle I'm facing is current. I'm going to have an electrically-dependent engine, with power provided by a dedicated engine bus fed directly from each battery through diodes. The trouble has been finding switches with enough of a current rating to handle this feed. The nominal average draw for the engine bus is about 10A (which isn't that bad, and I wouldn't normally be cycling this switch under that kind of load), but peak loads could be higher and I'd like some margin on that given how critical this switch would be. I'm thinking 30A is a good target, based on Ross's description of an alternate feed for the engine electronics (30A ATO fuse and a heavy duty switch).
However, there are relatively few switches out there rated for 20A, and even fewer rated for 30A. Almost none of them have any kind of locking mechanism, and I'd really prefer to avoid the big red flip-up milspec switch cover for multiple reasons.
NKK makes a locking toggle rated for 20A: https://www.digikey.com/product-detail/en/nkk-switches/S6AL/360-1927-ND/1007005
The Carling Contura rockers can handle 20A as well, but I've only found one supplier in the US that carries a version that can lock in the "on" position: https://www.onlinecomponents.com/carling-technologies/vdd1hw611kv000-16995989.html
Past that, I haven't found any viable options that don't take up tons of panel space (e.g. marine battery disconnects).
I kicked about the idea of using automotive relays on these feeds, but I'd prefer to minimize components and connections on the critical items.
Any other suggestions or ideas?
Beyond this I have fuel pump and coil loads to worry about (also things I want with locks or guards), but those could use the same switch if necessary.
* If I could really have what I wanted, I'd use illuminated square pushbuttons like the Korry switches on airliners, with flip-up transparent guards on the critical switches but those are expensive... cheaper options exist but I'd have to drive everything with relays, and that's too complicated.
Failing that, I'd prefer the Carlings over the traditional toggle switches.