AC/DC Panel Problems

[JoleGW33]

Can I get any help? Was going to post here but it doesnt let me attach pictures. Click this link for pictures http://www.thehulltruth.com/marine-electronics-forum/642885-ac-dc-panel-problems.html

"2003 Grady White 330 Express

Does anyone have an idea on whats going on? Its been a few months since the boat has been used, went to use it las weekend and this happens WITHOUT it being connected to shore power or the generator (no AC current), it just has batteries ON. The panel starts reading voltage and sometimes negative amperage on the right display.


Has anybody had this happen before? Any idea?

Thanks in advance."

 

[wspitler]

Interesting problem! An AC meter can provide strange indications when presented with a DC voltage. Since you have all of your AC fed systems off, it shouldn't be one of them feeding back internally, such as the AC/DC refrigerator, battery charger, etc. That makes me think it is a DC feed to an AC ground or some kind of short in the panel itself. How does it indicate with AC power on and all of the DC off via the battery switches? Does all of the AC stuff work properly? If it indicates OK there, I'd look for a DC short to an AC ground or other connection to an AC feed. Unless you have a bad circuit breaker switch, it will probably show up on the ground side. I'd pull the panel and check voltages with a multimeter to rule out the system's meter. Assuming all of your AC circuit switches are OK, look for a ground problem. I'm also assuming you have an AC generator and not an inverter. Good Luck!

 

[seasick]

Interesting problem! An AC meter can provide strange indications when presented with a DC voltage. Since you have all of your AC fed systems off, it shouldn't be one of them feeding back internally, such as the AC/DC refrigerator, battery charger, etc. That makes me think it is a DC feed to an AC ground or some kind of short in the panel itself. How does it indicate with AC power on and all of the DC off via the battery switches? Does all of the AC stuff work properly? If it indicates OK there, I'd look for a DC short to an AC ground or other connection to an AC feed. Unless you have a bad circuit breaker switch, it will probably show up on the ground side. I'd pull the panel and check voltages with a multimeter to rule out the system's meter. Assuming all of your AC circuit switches are OK, look for a ground problem. I'm also assuming you have an AC generator and not an inverter. Good Luck!

Inverter was my first though when I read the post. Obviously there is a draw on the DC side assuming the panel is displaying correctly

 

[JoleGW33]

Interesting problem! An AC meter can provide strange indications when presented with a DC voltage. Since you have all of your AC fed systems off, it shouldn't be one of them feeding back internally, such as the AC/DC refrigerator, battery charger, etc. That makes me think it is a DC feed to an AC ground or some kind of short in the panel itself. How does it indicate with AC power on and all of the DC off via the battery switches? Does all of the AC stuff work properly? If it indicates OK there, I'd look for a DC short to an AC ground or other connection to an AC feed. Unless you have a bad circuit breaker switch, it will probably show up on the ground side. I'd pull the panel and check voltages with a multimeter to rule out the system's meter. Assuming all of your AC circuit switches are OK, look for a ground problem. I'm also assuming you have an AC generator and not an inverter. Good Luck!

Yes I have an FP gen, all AC working fine. After 30 min with just the batteries ON the AC/DC panel went back to normal (humidity/condensation?). Later on the day I fired up the gen a ran de A/C for a while and all was working properly. Interesting what you said about a DC feed to an AC ground. I had my GPS replaced and had a problem with the ground of the unit. Maybe it has nothing to do with it but I will check it again and remove it and see if that fixes the problem. Thanks for the help!!!