Reward for lost Kraken!
Join Date: Apr 2006
Thanked 141 Times in 138 Posts
Rep Power: 11
Re: Wiring up electronics to a switch?
You've been mislead.
"4 kw is power and does not convert to amps (current)."
Power, in watts, equals potential (volts) times current (amps).
4kW for the radar, which in this case is normally running at 12.6 to 14.4 volts (engine off or on) converts to 317-277 amps. Roughly, 300 amps consumed by the radar when it is actively emitting. Since it is not doing that on a simple continuous basis, the average current that it takes will show up as way less, even when it is on.
You might think there's a discrepancy between ~300 amps and the <3 amps that Garmin told you. Well, 300 amps for a couple of microseconds, could well average into 3 amps of continuous power. The magic is all in having ALL the numbers, and having them in context. If it averages 3 amps while opearting, that's all you'd have to be concerned with.