Reverse Polarity

N

Nauticlops

.
Sep 12, 2019
14
Hunter 450 Passage San Diego
Howdy,

So the reverse polarity light turns on at the AC panel when I'm inverting from battery power. But the light is off when I'm connected to shore power. Any ideas? 2000 Hunter 450 Passage, Aims Picogolf 2500W inverter/charger soon to be a Xantrax XC Pro 3000W this weekend. I hope to get this figured out before the new inverter arrives. Thanks in advanced.
 
JoeWhite

JoeWhite

.
Mar 6, 2008
1,370
Catalina 1999 C36 MKII #1787 Coyote Point Marina, CA.
Are you using an extension cord that it's ends were replaced? If so may be they were reversed. You can test by plugging in to a wall outlet a tester and confirm the wall outlet is not reversed, then plug this cord into the wall and use your tester to see if the cord is misswired.
 
  • Like
Likes: Nauticlops
D

dlochner

.
Jan 11, 2014
13,070
Sabre 362 113 Fair Haven, NY
Nauticlops said:
Howdy,

So the reverse polarity light turns on at the AC panel when I'm inverting from battery power. But the light is off when I'm connected to shore power. Any ideas? 2000 Hunter 450 Passage, Aims Picogolf 2500W inverter/charger soon to be a Xantrax XC Pro 3000W this weekend. I hope to get this figured out before the new inverter arrives. Thanks in advanced.
Click to expand
The neutral and ground are likely wired incorrectly in the inverter. Install the new Xantrax and closely follow the instructions.
 
  • Like
Likes: Nauticlops
T

twalker H260

.
Dec 2, 2003
766
Hunter 260 winnipeg, Manitoba
First thing to do would be to check and see if the inverter output wires are connected properly at the inverter and at the main ac panel breakers. Manual for your current inverter is here:


P8 gives the connections at the back of the inverter.

Neutral (N) wires should be white, line (L) should be black and ground should be green.

You can also check to see if you have a reverse polarity situation with a multi meter set to AC voltage. Test one of you inverter powered outlets - Wide blade to ground prong should show no voltage while narrow prong to ground should show approximately 120 volts.
 
  • Like
Likes: Nauticlops
N

Nauticlops

.
Sep 12, 2019
14
Hunter 450 Passage San Diego
JoeWhite said:
Are you using an extension cord that it's ends were replaced? If so may be they were reversed. You can test by plugging in to a wall outlet a tester and confirm the wall outlet is not reversed, then plug this cord into the wall and use your tester to see if the cord is misswired.
Click to expand
No extension cords that I'm aware of. Unless it was something done at the factory somewhere in the boat, it's weird that the light is only on when using battery power.

dlochner said:
The neutral and ground are likely wired incorrectly in the inverter. Install the new Xantrax and closely follow the instructions.
Click to expand
This could be likely. I will investigate further. Is there any way to test the wire at the inverter terminal to rule out incorrect wiring somewhere else? Or switch the wires and see if the light goes away?
 
D

dlochner

.
Jan 11, 2014
13,070
Sabre 362 113 Fair Haven, NY
Nauticlops said:
This could be likely. I will investigate further. Is there any way to test the wire at the inverter terminal to rule out incorrect wiring somewhere else? Or switch the wires and see if the light goes away?
Click to expand
I would not just swap wires, that could prove disastrous. When the Reverse Polarity light comes on there is a voltage difference between the Neutral and Ground and there shouldn't be.

 
  • Like
Likes: Nauticlops
T

twalker H260

.
Dec 2, 2003
766
Hunter 260 winnipeg, Manitoba
Testing at the inverter is a bit more involved and the link from dlochner does indicate another potential source of a reverse polarity indicator. Small portable generators often light the reverse polarity light as they use a floating ground with no bonding between the ground and neutral.

Has your inverter always illuminated the reverse polarity indicator? If so this could be the cause.


There are methods that some have used to get around this issue. But since you will soon have a new inverter I wouldn’t bother with them.

To test at the inverter you could check when the inverter is operating for voltage on the output side connection between the output neutral and output ground connections - should be zero volts. Between the output line and neutral connections you should have approximately 120v and lastly between the ground and line connections you should have the same voltage as between the line and neutral connections. P17 of the previously linked manual shows the ac in and output connections.

Not all older inverters properly switched the ground bonding when powering the ac system from the batteries. This could be the case for yours. As a few others have suggested I would likely install your new inverter and then trouble shoot from there. Your new inverter does according to the manual do this ground bonding for you automatically.
 
Last edited:
  • Like
Likes: Nauticlops and Stu Jackson
A

artboas

.
Jun 1, 2009
1,845
Hunter 49 toronto
twalker H260 said:
Testing at the inverter is a bit more involved and the link from dlochner does indicate another potential source of a reverse polarity indicator. Small portable generators often light the reverse polarity light as they use a floating ground with no bonding between the ground and neutral.

Has your inverter always illuminated the reverse polarity indicator? If so this could be the cause.


There are methods that some have used to get around this issue. But since you will soon have a new inverter I wouldn’t bother with them.

To test at the inverter you could check when the inverter is operating for voltage on the output side connection between the output neutral and output ground connections - should be zero volts. Between the output line and neutral connections you should have approximately 120v and lastly between the ground and line connections you should have the same voltage as between the line and neutral connections. P17 of the previously linked manual shows the ac in and output connections.

Not all older inverters properly switched the ground bonding when powering the ac system from the batteries. This could be the case for yours. As a few others have suggested I would likely install your new inverter and then trouble shoot from there. Your new inverter does according to the manual do this ground bonding for you automatically.
Click to expand
A lot of good answers.
I can’t believe the inverter was wired backwards, as that’s so simple to get right.
My thoughts echo the previous post. Most inverters ground the neutral to ground when inverting, as that follows the “tie neutral to ground at first source of generation” rule.
If something has gone bad in the relay bonding circuit, then your neutral will be floating, and will be above ship’s ground.
As others have said, wait till the new unit is in. This will likely clear out
 
  • Like
Likes: Nauticlops
N

Nauticlops

.
Sep 12, 2019
14
Hunter 450 Passage San Diego
Thank you for the continued feedback! Here's a little more info on this issue. My original inverter was a Heart 2500, it would illuminate the reverse polarity light when inverting from the battery since the day I bought the boat. Eventually, the Heart inverter died and I replaced it with the AIMS 2500 following exactly the same connections for AC in/out as before. Still, the reverse polarity light would come on while inverting from the battery. The intensity of the light would change between selecting Outlets Port and Starboard. Port or Starboard individually would produce a dim polarity light, Both would produce a bright polarity light. I'll follow the recommendation to keep the wiring the same as it currently is and will report back. Thank you once again!
 
  • Like
Likes: JamesG161
N

Nauticlops

.
Sep 12, 2019
14
Hunter 450 Passage San Diego
Well you guys were right, everything is working and not even the faintest reverse polarity light to be seen! Also had a chance to run a chassis ground to the main negative bus from the inverter because for some reason the factory didn't. Thanks for all the help!
 
SycloneDriver

SycloneDriver

.
Jul 23, 2009
917
Beneteau 31 Oceanis Grand Lake, Oklahoma
The "reverse polarity" indicator isn't really accurate. What it really should say is "voltage on neutral referenced to ground" or something similar.

The neutral and ground are probably not bonded at the inverter. It's not usually a problem other than you loose the safety function the "ground" provides. Many, many inverters are "floating ground." They can normally and easily be bonded.

I see you have resolved your problem, good job.
 
You must log in or register to reply here.
Top Bottom