Shorepower and Reverse Polarity - Page 2 - SailNet Community
 1Likes
Reply
 
LinkBack Thread Tools
post #11 of 30 Old 06-08-2007
Senior Member
 
ebs001's Avatar
 
Join Date: May 2006
Location: Ottawa, Canada
Posts: 2,205
Thanks: 6
Thanked 21 Times in 19 Posts
Rep Power: 10
 
Your GFI probably won't reset because of the reverse polarity and therefore none of your other 120v receptacles will work. You need to check the polarity of the marinas 30 amp receptacle. You could also try plugging into the other 30 amp receptacle on the same pedestal to see if that corrects the situation. Then you'll know if it's the pedistal or just your receptacle.

Last edited by ebs001; 06-08-2007 at 06:26 AM.
ebs001 is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #12 of 30 Old 06-08-2007
Telstar 28
 
sailingdog's Avatar
 
Join Date: Mar 2006
Location: New England
Posts: 43,290
Thanks: 0
Thanked 15 Times in 12 Posts
Rep Power: 14
         
Did you check with the marina to see if they had done any work on the wiring over the winter? If so, they may have accidentally reversed the polarity on the system.

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.
sailingdog is offline  
Quote Quick Reply Share with Facebook
post #13 of 30 Old 06-08-2007
Junior Member
 
Join Date: Jun 2007
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
credit goes to Art Richard IP32 #34 "Lagniappe" (St. Petersburg, FL) for the following dialogue:

"LOW GLOW OF REVERSE POLARITY LIGHT:
A low-level reverse polarity light on an IP when there is heavy current draw (like a heater or air conditioner) is not unusual. The reason is as follows:

1. The reverse polarity light is connected between the AC neutral (white) and AC ground (green) wires inside the distribution panel. If there is a voltage between these two lines, the light lights in proportion to the voltage.

2. When using shore power, the neutral and ground wires are connected together somewhere on the shore at a power distribution box. Between that point and your boat load (heater) are many feet of wire. Normally the AC current flows through the hot (black) wire to the load (heater) and back through the neutral (white) wire to the aforementioned distribution box (of course the current also flows through the black and white wire back to the power generator, but that is not pertinent to this discussion).

3. When current flows through a wire, the small resistance of the wire causes a voltage drop which is proportional to the length of the wire and the resistance of the wire. You see this on your AC voltage meter when you turn on a high current load (heater). Depending on the load and the length of wire, this voltage drop is sometimes 10 or more volts.

4. The reverse polarity lamp is effectively measuring the voltage between the neutral and ground wires at the boat. Since the ground wire is not (normally) carrying any current, there is no voltage drop in this wire. The neutral wire however is carrying current and does have a voltage drop. This voltage drop in the neutral wire appears across the reverse polarity lamp, causing it to glow, the brightness depending on the actual voltage drop in the neutral wire. This glow is not an indication of reverse polarity, and will not normally cause a problem.

BRIGHT GLOW OF REVERSE POLARITY LIGHT:
When you have a bright glow in the reverse polarity here is what happens:

1. In order for the bright glow to happen, there must be a high (about 100+ volts) voltage difference between the neutral and ground wires in your boat.

2. When the polarity is reversed, the power source's hot (black) wire is connected to the boat's neutral distribution, and the white (neutral) wire is connected to the boat's black wire. This can cause electrolysis and lots of other problems as well as being very unsafe. NEVER IGNORE A BRIGHT REVERSE POLARITY LIGHT! "

( Art continues with the following - not pertinent to your problem, but included anyway )

"YOUR GENERATOR PROBLEM:
Just because the generator does not light the reverse polarity light on another (non IP boat) does not prove that you do not have reverse polarity. It is hard to determine your problem without measuring voltages, but here are some possible causes:

1. Your generator has a reversed internal polarity. You need to measure the AC voltage between the neutral and ground pins on the generator output connector to verify this. On a "standard" (wall type) socket) the neutral is the wider flat slot and the ground is the round hole. If you get over 100 volts, the generator has reverse polarity. If you get a fluctuation in voltage, you probably have a floating ground.

2. Your generator has a floating ground (This can cause the reverse polarity light). If this is the case, you need to connect the neutral line to the ground (case) of the generator."

now back to sailnet:

for the problem you have of the indicator light, a question would be : is it totally off, low, or bright?

Clues to your situation are:
1) you're always plugged in at the dock - so with your batteries constantly topped, there would not even be a low glow (very faint perhaps) of the light.

2) when you replaced a dead battery and plugged in again, the system started working harder to get the bank up to specs. A low glow would be normal and actually shows everything is working OK. But the low glow would be a change from no light before and begs an explanation. Hopefully this is it.

3)before sailing, you have no light (batteries are topped, there's little draw), then after sailing, and perhaps using more amps than you made while underway, you plug in again - if a low glow is seen this is normal because you need to draw on you system to get back to full banks.

good luck. all the advice in the world doesn't mean you shouldn't get a reverse polarity tester and plug it in. cost is about 10 dollars at a hardware store.
phaiakian is offline  
Quote Quick Reply Share with Facebook
post #14 of 30 Old 06-08-2007
Member
 
Join Date: Feb 2007
Location: Virginia
Posts: 78
Thanks: 3
Thanked 2 Times in 2 Posts
Rep Power: 9
 
Thanks for the post by Art Richards....I've had exactly that problem for 12 years and no one has been able to explain it except to say "don't worry"...the light glows very brightly when the water heater is on and very faintly at other times.

Bruce3
bhcva is offline  
Quote Quick Reply Share with Facebook
post #15 of 30 Old 06-12-2007
Hitchin' a ride
 
bestfriend's Avatar
 
Join Date: Sep 2006
Location: In my mind, I live in Oslo
Posts: 3,191
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 11
     
Oh Crap!

I just happened to push the "test polarity" button today on the boat and it lit up like a christmas tree. I didn't think much of it, everything was working fine and has been since we moved to the new slip a month ago(yikes!). Not being much of an electrician, I figured I would check out sailnet for the answer. Not the answer I was hoping to hear. Now I am across the Bay for the night, 40 minutes away with a couple (read half a bottle) of glasses of red wine in me. So, stay tuned for tomorrow's local fire report! Wish me luck.

Great men always have too much sail up. - Christopher Buckley


Vaya con Dios
bestfriend is offline  
Quote Quick Reply Share with Facebook
post #16 of 30 Old 06-13-2007
Hitchin' a ride
 
bestfriend's Avatar
 
Join Date: Sep 2006
Location: In my mind, I live in Oslo
Posts: 3,191
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 11
     
Well, she survived through the night. The only way I could get the polarity light to go off was to unplug the shore power. I didn't have time to check the dock receptacle with a meter, that will be tomorrow. Watch the news for "sailor electrocuted". If the dock receptacle is not reversed, could the problem be on board?

Great men always have too much sail up. - Christopher Buckley


Vaya con Dios

Last edited by bestfriend; 06-13-2007 at 01:34 AM.
bestfriend is offline  
Quote Quick Reply Share with Facebook
post #17 of 30 Old 06-13-2007
Telstar 28
 
sailingdog's Avatar
 
Join Date: Mar 2006
Location: New England
Posts: 43,290
Thanks: 0
Thanked 15 Times in 12 Posts
Rep Power: 14
         
Yes, but I doubt it. Get one of the dongles that allows you to plug a regular extension cord in to your shorepower outlet and then get a regular household polarity checker... keep them both aboard the boat, and use whenever you're at a different marina—to check the wiring status before you plug your boat in.

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.
sailingdog is offline  
Quote Quick Reply Share with Facebook
post #18 of 30 Old 06-13-2007
Junior Member
 
Join Date: Jun 2007
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Oft Junior member! I think,that this system your boat is connected to,is a 240 120 V system.Which means that you have two or three wires in to the distrybution box on the dock +groundwire.If you measure between one of them two or three wires and the ground you get 120 Volts.The ground and the neutral wire are the same thing.Red light on your switchpanel means leak to ground on your outlet.Since here in America you don´t have groundleak breakerswitch,this light is in stead.
Capthor
capthor is offline  
Quote Quick Reply Share with Facebook
post #19 of 30 Old 06-13-2007
Hitchin' a ride
 
bestfriend's Avatar
 
Join Date: Sep 2006
Location: In my mind, I live in Oslo
Posts: 3,191
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 11
     
Please forgive my naivete with electrical systems on the water. There is a button marked "test polarity" and then a light next to it that says "reversed". I think I misunderstood that as "push this button to test your polarity". I am guessing that it means "push this button to test the polarity light/alarm system". So, you push the button and the light goes on telling you that your check system is operative. My light is not always on. Thinking on it more now, I would think that the light would go on automatically if there was a problem.
Update: I got the confirmation that I needed. The button is a check system. Thanks all.

Great men always have too much sail up. - Christopher Buckley


Vaya con Dios

Last edited by bestfriend; 06-14-2007 at 11:40 AM.
bestfriend is offline  
Quote Quick Reply Share with Facebook
post #20 of 30 Old 12-03-2007 Thread Starter
oft
Junior Member
 
Join Date: Apr 2006
Posts: 23
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
UPDATE: As it turned out, our neighbor, while unplugging from shorepower, had bumped our cable causing it to pull out somewhat from the connection and this, in turn, resulted in the reverse polarity situation. So, checking connections and terminations is not a bad place to start.
oft is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome