Electrical Issue

[alcoprop]

My boat is a 2021 23 MXZ. Last year I had what I believe is electrical related, small screen would go blank, white noise in the speakers, large screen went completely out and had to be replaced and some other things. I have a fairly large stereo system in the boat. Did a battery upgrade this year, 3 XS Power on one side of the switch and the stock batteries on the other side, added a 3 bank and 2 bank NOCO on board charger. Did this at the house and everything was good except still had the white noise. Now since the boat is back at its home on the lake I have noticed another issue. The boat sits on a lift at a public marina. I reached down one day and touched the prop bc there was something on it and I got shocked while I was holding onto the dock. Chargers were plugged into the outlet on the dock. Told the marina and they had their electrician check everything. He said it was all good on the marina side. So I brought my voltage detector down (the stick style) and anywhere I touch the boat it detects voltage while I have it plugged in. Unplug the chargers and it goes away. Grounds are all tight and look good. I have also noticed now that the NOCOs detect high voltage and keep shutting down on my batteries. Only way I can make it work is turn the banks off except for one on each battery. I’m still thinking it might be a grounding issue and this is why I can’t get rid of the white noise. White noise is for sure louder while the engine is running. Any help is much appreciated. 

[justgary]

I would not trust the marina folks.  Grab a meter and carefully test the outlet you use by inserting one probe into the rounded ground socket and then test the two slot sockets for voltage.  You should have zero volts at the longer (Neutral) slot and 120 VAC at the shorter (Hot) slot.  If the voltage is not, contact the marina again and show them.  If the voltage is correct, contact NOCO.

[alcoprop]

On 6/23/2022 at 9:21 AM, justgary said:

I would not trust the marina folks.  Grab a meter and carefully test the outlet you use by inserting one probe into the rounded ground socket and then test the two slot sockets for voltage.  You should have zero volts at the longer (Neutral) slot and 120 VAC at the shorter (Hot) slot.  If the voltage is not, contact the marina again and show them.  If the voltage is correct, contact NOCO.

Did that and everything is good. I will call NOCO and see what they say. 

[justgary]

37 minutes ago, alcoprop said:

Did that and everything is good. I will call NOCO and see what they say. 

To be honest, it isn't clear to me why they don't have a ground lug on the charger.  I get it that they want their charge voltage to float so they can independently charge batteries (that may be in series), but at some point a floating charge voltage is going to develop some potential with respect to ground.

[shawndoggy]

1 hour ago, justgary said:

To be honest, it isn't clear to me why they don't have a ground lug on the charger.  I get it that they want their charge voltage to float so they can independently charge batteries (that may be in series), but at some point a floating charge voltage is going to develop some potential with respect to ground.

What do you mean by a "ground lug"?  It is a grounded (3 prong) cable 120v?

[justgary]

6 hours ago, shawndoggy said:

What do you mean by a "ground lug"?  It is a grounded (3 prong) cable 120v?

Yes, but the black wire to the batteries is not necessarily connected to the third prong at all.  I suspect that the black wire floats.