New Electrical Issue

[porman]

I spent last week underneath my upper helm taking care of the rats nest of wiring and getting rid of 13 inline fuses. I used Blue Seas 6 individual circuit spade fuse blocks. There are 2 circuits under the helm, one from the main battery panel through a 50 amp breaker without an indicator light. The other is through the main electrical panel and a switchable breaker with an indicator light. I moved 3 things from the battery panel to the switchable breaker. The 3 things are an AIS transponder, a VHF radio , and a chartplotter, all Raymarine. With the radio and chartplotter turned off (the AIS doesn't have a switch) I turn off the breaker and the indicator light glows for a while and slowly goes out. If I remove the fuses from the 3 things the light goes right out. Is this normal and I didn't notice before when they were on a different circuit. Or is there a problem I should look into? With a voltmeter hooked to the circuit, I turn off the breaker, run to the flybridge, and see about 1.5 volts that slowly drops. I hope that's an adequate explanation. I'm hoping someone has an answer.

 

[STB]

I cant quite visualize what you have or the arrangement of the fuses to the breaker.

Let me assume that the breaker serves a feed that branches off to three devices, each with its own fuse.

Devices may have capacitance, especially in their power supplies, that can bleed charge back on the circuit when they turn off.

In some cases the capacitance is there even when "turned off", because some minor functions remain powered, e.g. memory, so the switch opens later in the circuit.

Remove the fuses one at a time and you'll find the culprit(s). My bet is the AIS. Radios are picky about power and it sounds like the AIS was powered up when shut down.

Whether or not I'd be concerned depends upon how long "a while" happens to be. A small few seconds I'd ignore. Much beyond that, I'd call tech support for the implicated device(s) and ask.

 

[porman]

That's correct, a breaker with an indicator light that powers three devices, each with it's own fuse. I removed all three fuses and replaced them one at a time. The VHF had no effect. The AIS let the light glow for a very short time. With the chartplotter the light glowed longer. I believe you're right that the chartplotter and AIS must have some capacitance. I was just surprised to see it. Thanks for the reply.

 

[Madhatter53]

I had a few electronics that did the same thing and never had any issues.

 

[High Wire]

One or more of the devices has a capacitor across the power leads for noise reduction that holds the voltage up for a little while. Non issue.

 

[porman]

Thanks everyone. I feel better now. And the wiring underneath the helm looks a lot better.