Dumb Electrical Question
If both of these circuits are wired through a common relay, does that relay need a capacity of 30A (or greater)?
Or would a 20A relay be sufficient?
Andrew

But it appears 20A ultra-micro relays are the largest available. If there are 30A ultra-micro relays, I'm not sure where to find them.
Last edited by TipsyMcStagger; May 28, 2019 at 01:37 PM.
A typical high impedance injectors draw about an amp. Even if all eight are on at the same time, current draw would be about 8A. A 20 amp relay should be fine.
The fuse is designed to protect the wiring against a short circuit, so the max size of the fuse is designed based on the wire gauge rather than the load. You're doubling the number of injectors, but you're not increasing the size of the wiring feeding any injector. I don't think a 30A fuse is a good idea. A single 20 amp fuse should be fine.
A typical high impedance injectors draw about an amp. Even if all eight are on at the same time, current draw would be about 8A. A 20 amp relay should be fine.
The fuse is designed to protect the wiring against a short circuit, so the max size of the fuse is designed based on the wire gauge rather than the load. You're doubling the number of injectors, but you're not increasing the size of the wiring feeding any injector. I don't think a 30A fuse is a good idea. A single 20 amp fuse should be fine.
You're suggesting combining both left and right injector/coil banks into a single 20A fused circuit?
You're suggesting combining both left and right injector/coil banks into a single 20A fused circuit?
I don't have any data on coil current requirements, but I would guess they have a larger current draw than high impedance injectors.
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I don't have any data on coil current requirements, but I would guess they have a larger current draw than high impedance injectors.
There doesn't seem to be a 30A ultra-micro relay available to fit in the Bussmann block, so I'll use a different fuse block and run both 15A circuits through a 30A relay.
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Last edited by EFIHARNESS; May 29, 2019 at 07:28 PM.
If so, that surely simplifies things!









