reverse polarity problem - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 
  #1  
Old 07-22-2008
Member
 
Join Date: Jul 2007
Posts: 34
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
sailingtime is on a distinguished road
reverse polarity problem

I am new to the luxury of having shore power which also means I am clueless to dealing with any problems with it other than plugging in the cord. Up until last weekend everything worked great until I lost power and the “reverse polarity” indicator light came on. I discovered that the indicator light would go out and the normal “service” light would come on if nothing was plugged into any receptacles. As soon as something was plugged back in the “service” light went out and the “reverse polarity” light came on. Can anyone give me an idea of what I am dealing with and how best to approach fixing it?
Reply With Quote Share with Facebook
  #2  
Old 07-22-2008
hellosailor's Avatar
Plausible Deniability
 
Join Date: Apr 2006
Posts: 10,533
Thanks: 2
Thanked 81 Times in 79 Posts
Rep Power: 10
hellosailor has a spectacular aura about hellosailor has a spectacular aura about
It is possible that the marina has reversed the power leads on your dock, or that your own shore power wiring is crossed at some point. Go to any hardware store, for $5 you can buy a little power outlet tester with three lights on it, that plugs directly into a socket to test for these things. If necessary, get an adapter so it can plug directly into the dock power, or wire one up.

If you've never plugged into shore power before..odds are 50-50 whether it is your wiring, or the marinas. If no one else has a problem with the marina power--time to check your wiring out. If you find "household" grade power cords on the boat, that's a big hint right away.
Reply With Quote Share with Facebook
  #3  
Old 07-22-2008
sailingdog's Avatar
Telstar 28
 
Join Date: Mar 2006
Location: New England
Posts: 43,291
Thanks: 0
Thanked 9 Times in 9 Posts
Rep Power: 13
sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice
If the reverse polarity light is off when you have the boat plugged in to shorepower, but it comes on when you plug something into the boat, you may have a bad appliance or outlet on the boat.

I would second HS's recommendation of getting a polarity tester at the hardware store.

It looks a lot like this:



Start by checking the marina's shore power outlet. Then check the shore power cord, while it is plugged into the outlet. If it is fine at these two points, the problem is on the boat someplace. Then check the boat when it is plugged into the shore power cord. Unplug all the 110 VAC devices and use the polarity tester to check each outlet. IF they're all fine, then it is one of the appliances on your boat.

BTW. DON'T FORGET THAT THE SHOREPOWER DOCK SIDE CONNECTION SHOULD BE THE LAST TO BE MADE AND THE FIRST TO BE DISCONNECTED. YOU DON'T WANT TO BE WALKING AROUND THE DOCK WITH A LIVE AC CORD IN YOUR HAND—SINCE IT MIGHT WELL KILL YOU IF YOU SLIP AND FALL IN HOLDING IT.

To plug the boat in:

Open the shorepower socket lid.
Connect the cord to the shore power outlet on the boat.
Tie or wrap the cord so that it can't fall in the water as you lead it back to the shore power outlet on the dock.
Connect the shorepower cord to the dock outlet.
Turn on the breaker.

To disconnect the boat:

Turn off the breaker.
Remove the shore power cord from the shore power outlet on the dock.
Unwrap and untie the shore power cord and coil it.
Disconnect the shore power cord from the boat.
Close the lid on the shore power socket.

Don't skip steps in this... 110 VAC and water don't mix nicely.
__________________
Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
Reply With Quote Share with Facebook
  #4  
Old 07-22-2008
Senior Member
 
Join Date: May 2007
Posts: 547
Thanks: 3
Thanked 3 Times in 3 Posts
Rep Power: 8
SteveInMD is on a distinguished road
The polarity light is there to protect you from ending up with revered polarity from shore power. Normally this is only an issue when you are in remote places and you have to wire up your own adapters to connect to shore power. If you didn't make any wiring changes on your boat and it was working before it's probably something your marina needs to fix. It could be a problem on your whole dock or just your connection point. Unless you are working with someone who knows electricity thoroughly, this is a job for a pro. AC power can kill you - your boats 12 volt DC system probably wont.
Reply With Quote Share with Facebook
  #5  
Old 07-22-2008
sailingdog's Avatar
Telstar 28
 
Join Date: Mar 2006
Location: New England
Posts: 43,291
Thanks: 0
Thanked 9 Times in 9 Posts
Rep Power: 13
sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice
Steve-

You're making assumptions not in evidence... if the power went out due to a storm, he could easily have a fried piece of equipment on his boat that is causing the RP situation. He needs to check the AC at the shorepower box and at the end of the shorepower cable. If it is good at those two points, the problem is somewhere on the boat.

From his description, where the RP light doesn't come on until he plugs something in to the AC system on the boat, I seriously doubt that the RP problem is in the marina shorepower system.

A ten year old could run the simple checks I've described above.. They're not rocket science. While, I agree that working on a boat's 110 VAC system can be very dangerous.... doing basic trouble shooting like I describe should be something that all boat owners should be capable of.
Quote:
Originally Posted by SteveInMD View Post
The polarity light is there to protect you from ending up with revered polarity from shore power. Normally this is only an issue when you are in remote places and you have to wire up your own adapters to connect to shore power. If you didn't make any wiring changes on your boat and it was working before it's probably something your marina needs to fix. It could be a problem on your whole dock or just your connection point. Unless you are working with someone who knows electricity thoroughly, this is a job for a pro. AC power can kill you - your boats 12 volt DC system probably wont.
__________________
Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
Reply With Quote Share with Facebook
  #6  
Old 07-22-2008
Senior Member
 
Join Date: May 2007
Posts: 547
Thanks: 3
Thanked 3 Times in 3 Posts
Rep Power: 8
SteveInMD is on a distinguished road
SD -

I don't disagree with anything you posted. Further, I wasn't responding to your post at all, as we were both writing our replies at the same time. The purpose of my post was simply to offer a little information about why the polarity light even exists on a boat in the first place. Also, since the polarity tester was already suggested, I was simply saying that once the problem has be identified, repairing the AC system should be left to a pro. (Of course this doesn't include unplugging and appliance.)
Reply With Quote Share with Facebook
  #7  
Old 07-22-2008
sailingdog's Avatar
Telstar 28
 
Join Date: Mar 2006
Location: New England
Posts: 43,291
Thanks: 0
Thanked 9 Times in 9 Posts
Rep Power: 13
sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice
If the problem is in one of his AC appliances, an electrician may not be required.
Quote:
Originally Posted by SteveInMD View Post
SD -

I don't disagree with anything you posted. Further, I wasn't responding to your post at all, as we were both writing our replies at the same time. The purpose of my post was simply to offer a little information about why the polarity light even exists on a boat in the first place. Also, since the polarity tester was already suggested, I was simply saying that once the problem has be identified, repairing the AC system should be left to a pro. (Of course this doesn't include unplugging and appliance.)
__________________
Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
Reply With Quote Share with Facebook
  #8  
Old 07-22-2008
EO32's Avatar
Senior Member
 
Join Date: Jan 2008
Location: Fremont, WA
Posts: 165
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 7
EO32 is on a distinguished road
Now I'm confused.

What does the "reverse polarity" indicator mean?

If it means the "Black" Line side of the AC and the "White" netural side are reversed, then why would it come on without shore power connected? Unless he has another source of power such as an Inverter.

If it never came on before, then I would agree with SD that something is broken.

If it refers to the DC system, then that's a whole new ballgame.

Chris
__________________
If a man must be obsessed by something, I suppose a boat is as good as anything, perhaps better than most. A small sailing craft is not only beautiful, it is seductive and full of strange promise and the hint of trouble.

- E.B. White
Reply With Quote Share with Facebook
  #9  
Old 07-22-2008
RAGTIMEDON's Avatar
Senior Member
 
Join Date: Apr 2007
Location: St Peters, MO
Posts: 389
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 8
RAGTIMEDON is on a distinguished road
Realize that a competent professional was once a beginner--If you have the motivation to learn to do your own maintenance, simple electrical checks like SD describes are a good place to start. I am personally reluctant to "go with a pro" unless I know that professional well. I've seen and corrected some terrible mistakes made by professionals -- personally I prefer a truly motivated amatuer, so I do all my own work unless it calls for expensive specialized tools I do not posess! SD is right, if you are going to continue to be a boatowner, you need to develop some basic skills! Buy that polarity tester and go for it! Life is a learning process! 120VAC may burn if you are careless, but not likely to be fatal unless you are swimming when you touch the wire! If you are really nervous about it, wear rubber gloves to insulate your hands!
__________________
Don
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

1980 Endeavour 37 sloop, currently in the Mississippi near St Louis
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #10  
Old 07-22-2008
sailingdog's Avatar
Telstar 28
 
Join Date: Mar 2006
Location: New England
Posts: 43,291
Thanks: 0
Thanked 9 Times in 9 Posts
Rep Power: 13
sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice
Sailingtime—

Just curious, but does your boat have an inverter/charger on it?? If the RP light is out when you power up the shorepower AC breaker, then it is pretty likely that the problem is on the boat someplace. If you had an inverter/charger that the outlets are connected to, and it got damaged, that might explain it. It might not...I really don't have enough information about the shorepower AC setup on your boat to say one way or the other... and anything we say will be pure speculation.

Quote:
I discovered that the indicator light would go out and the normal “service” light would come on if nothing was plugged into any receptacles. As soon as something was plugged back in the “service” light went out and the “reverse polarity” light came on. Can anyone give me an idea of what I am dealing with and how best to approach fixing it?
Chris-

A Reverse Polarity indicator on an AC panel is designed to show you if there is voltage coming in over the neutral line. It does not indicate whether the voltage is or isn't present on the black "hot" line, only whether any significant voltage is showing on the neutral "white" line.

The fact that it only comes on when he plugs something into the outlets on the boat tends to lead me to believe the problem is with something on the boat. Either the wiring, an inverter/charger, or one of the appliances.

AFAIK, none of this particular discussion has anything to do with the DC side of the boat.
Quote:
Originally Posted by EO32 View Post
Now I'm confused.

What does the "reverse polarity" indicator mean?

If it means the "Black" Line side of the AC and the "White" netural side are reversed, then why would it come on without shore power connected? Unless he has another source of power such as an Inverter.

If it never came on before, then I would agree with SD that something is broken.

If it refers to the DC system, then that's a whole new ballgame.

Chris
__________________
Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pearson 30 reverse problem wha3 General Discussion (sailing related) 5 02-27-2013 11:19 AM
Reverse polarity telekitr Gear & Maintenance 28 02-12-2008 08:59 PM
Shorepower and Reverse Polarity oft Gear & Maintenance 20 12-03-2007 09:46 PM
problem motoring in reverse pegasus1457 Gear & Maintenance 6 10-01-2007 07:29 AM
reverse polarity newport33 Gear & Maintenance 1 08-18-2001 06:32 PM


All times are GMT -4. The time now is 01:45 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.