View Transcript

Hide Transcript

Transcript is auto-generated.

we've got a question from a fellow boater named Matthew Matthew asks Jeff in the past few months I've been on my boat on a mooring board and using a generator probably a AC generator although Matthew didn't say it but let's assume it's an AC generator out of nowhere my AC reverse polarity light came on and hasn't done this before how do I fix it okay quick question for Matthew first of all what's a reverse polarity light and reverse polarity to what so reverse polarity is a term used to describe a situation with AC systems so alternating current system so like uh basically generators or Shore Power Systems those are AC systems as opposed to Battery Systems which are DC direct current systems alternating current versus direct so when we have an alternating current system 120 220 whatever it is aboard a boat at the main panel there should be and most of us have this a little light and generally it's labeled it's reverse polarity and it's generally red that little red light measures um literally it's powered between two things um it's powered between the neutral and the AC neutral so that's what's called the ground connector and the AC ground which is called the grounding connector so it's a light that in all circumstances uh should really be zero if things are working out perfectly well because your ground and neutral should always be at the same potential meaning there should be no voltage differential between the two now when we're connected to shore power uh systems let's say for example a Merino or destination Marina it does sometimes happen that the electrician who powered the pedestal actually inverted the leads so the hot is on the neutral and the neutral is on the hot and if that's the case if the hot is on the neutral then the reverse polariolite which measures a voltage differential between the neutral and the ground is going to see maybe 120 or 220 volts and that light will shine brightly telling you that the neutral was swapped for the hot telling you that you have reverse polarity and it is serious and should be addressed

separate videos all on that if you want to geek out talked about it before all right so check out reverse polarity on YouTube on our Channel or reverse polarity on our website and there's going to be lots of information uh and even articles and further videos just on this topic so now the weird question though is this is happening from about Adam Mooring ball running a generator probably AC and seeing a reverse polarity light well what could happen that light is not on or off I know that that's what we expect but it is possible for a neutral to ground connection to not be that good and to maybe have 5 volts 7 volts a voltage differential and for that light to be shining but very dimly so what I would say Matthew the first thing that I would do and you need to make sure that you're comfortable doing this or have an electrician do it for you is I would actually measure with an AC multimeter but I would measure the voltage differential between the neutral and the ground at my AC panel and when your generator is running which is a source of power that generator should have a good neutral to ground tie because it's a source of power not only when it's working of course but a generator should be have a what's called a neutral or ground type because all sources of power and inverter um Shore power stations all of that have a neutral or ground tie so it's possible that you're neutral to ground tie on your generator is going it's not going well and that's not normal and serious so you're going to want to make sure that the generator has that really good generator ground to neutral tie and you'll want to measure that and what you're probably seeing here is some sort of bad connection on your generator that's what I would guess but it's probably not reverse polarity because reverse polarity is not something that randomly happens it's it's a wiring issue that is done opposite of what it should be and it can't flip-flop if it was straight good polarity a month ago it's very rare to see a situation where you have reversible area unless there's some sort of wiring mistake where the wires get crossed somehow and this would be very serious but in normal cases reverse polarity only is something you uncover right after doing the work it's not something you're going to uncover suddenly 10 months or 10 years after the work has been done so to me it's probably a grounding issue uh and a great question for Matthew and thanks for all of you for tuning in and watching into another tech talk be safe on the water and let us know what your troubles have been with reverse polarity lights down below because remember sharing is caring thanks for watching so if you're curious again go on our website and find out more answers and solutions with this sort of setup and thanks for asking and thanks for all of you for listening and tuning in