Mystery involving the reverse polarity light

[David Discenza]

I've been experiencing something I don't understand and can't explain. For no reason I can see, the reverse polarity light will suddenly come on. This automatically shuts off ac power to the boat (including the much-needed air conditioning). If I disconnect the shore power plug, wait a few seconds, and then plug it back in, the light goes out and power is restored....until the light comes on again.

My understanding of reverse polarity is that it happens when the hot and neutral wires are reversed. Were that the case, the reverse polarity light should be lit all the time. What else could be causing this problem?

[Jim Hardesty]

For no reason I can see, the reverse polarity light will suddenly come on. This automatically shuts off ac power to the boat

David,
I'm not one of the electrical experts, but I believe you are mistaken that the reverse polarity light will in itself shut off the power, think it's just an indicator of voltage between the neutral and ground.  I don't understand what gets shut off.  Is it one of the circuit breakers or does the Air shut down?  When I've had the reverse polarity light a good cleaning of the shore power cord connections cured it.
FWIW  I would only run it to trouble shoot, wouldn't feel safe sleeping with the AC on, or leaving the boat plugged in. 
Jim

[Ron Hill]

David : I see that you have a MK1.5 hull #1244.  I'd remove the main electrical panel and check the shore power and reverse polarity connections.

A thought

[David Discenza]

For no reason I can see, the reverse polarity light will suddenly come on. This automatically shuts off ac power to the boat

David,
I'm not one of the electrical experts, but I believe you are mistaken that the reverse polarity light will in itself shut off the power, think it's just an indicator of voltage between the neutral and ground.  I don't understand what gets shut off.  Is it one of the circuit breakers or does the Air shut down?  When I've had the reverse polarity light a good cleaning of the shore power cord connections cured it.
FWIW  I would only run it to troubleshoot, wouldn't feel safe sleeping with the AC on, or leaving the boat plugged in. 
Jim

Jim,
Thanks for your reply. No circuit breakers pop when the light comes on. Whatever circuitry at work behind the panel shuts off the ac power to the rest of the boat. Your idea of cleaning the male contacts on the shore power plug (both on the boat and the power cable) is worth trying as when I disconnect the power cable from the boat and then reconnect it, the reverse polarity light goes out. I hope it's something as simple as dirty contacts.

[Jim Hardesty]

David,
Something to be concerned about is if it's a bad shore power plug connection is arcing, may have like a small spot weld on the connection.  If it's on the male file it off, on the female probably can't tell.  If it's the shore power to boat connection you disconnect and reconnect to restore power, are you using the threaded ring connector?  google "shore power cord ring"
I would clean with WD-40 and scotch brite both the male and female plug connections.  Inspect as well as you can and use a small amount of electric grease, from hardware or electric supply.  Or try another power cord.
Would also follow Ron's suggestions of checking all the power connections.

IMHO Your problem is something to be very concerned with.  If it is a poor connection at the shore power to boat plug this could start a fire.  May need a new power cord and or a new boat plug.
Lots of luck,
Jim

[David Discenza]

David,
Something to be concerned about is if it's a bad shore power plug connection is arcing, may have like a small spot weld on the connection.  If it's on the male file it off, on the female probably can't tell.  If it's the shore power to boat connection you disconnect and reconnect to restore power, are you using the threaded ring connector?  google "shore power cord ring"
I would clean with WD-40 and scotch brite both the male and female plug connections.  Inspect as well as you can and use a small amount of electric grease, from hardware or electric supply.  Or try another power cord.
Would also follow Ron's suggestions of checking all the power connections.

IMHO Your problem is something to be very concerned with.  If it is a poor connection at the shore power to boat plug this could start a fire.  May need a new power cord and or a new boat plug.
Lots of luck,
Jim

Jim,
I went to the boat today to check my lines as we have a tropical storm coming up the coast. I took the time to inspect my 1-year-old shore power cable. There is no evidence of arcing at either end. I took the time to take apart and inspect the electrical port in the cockpit. There was no corrosion of any of the wires and I made certain the connections were tight. I did the same at the master breaker switch and at the master panel. I switched the power on and got a green light on the panel. I did not have the luxury of time to stay to see if the fault light came on. I've turned the power off and have had a discussion with the electrician at our marina who will take some time to give the electrical system a thorough going over. Failing this, I have a Catholic priest friend and I'm going to have him perform an exorcism as possession by an evil spirit is the only other explanation for this phenomenon.

[David Discenza]

David : I see that you have a MK1.5 hull #1244.  I'd remove the main electrical panel and check the shore power and reverse polarity connections.

A thought

Ron,
Thanks for your reply. I did that today and everything appears to be in order. All the connections were tight.

David

[Ron Hill]

David : Knowing the boat, it might have been some spilled Irish Coffee!!   Smile - In Jest!!

A thought

[KWKloeber]

David

I wonder if it could be an intermittent leakage between two poles, not actually a short or reversed polarity?
If there was a very low amperage leak between the hot and grounded (white) conductors then the RP bulb (between the white and green ground conductor) could light.

You might try cleaning up and spraying the faces of both cord ends with a dielectric and definitely check with a meter for any leakage between the three poles of your shore cable. 

[scgunner]

David,

You're boat (Mk 1.5) is fairly close to mine (Mk 1) so you may have the same electrical panel. My panel has three lights, two amber, one red and a circuit breaker just below. How do your lights normally indicate? My ambers normally flicker, one or both depending on where I'm hooked up at. When you get the red reversed polarity light what do your ambers do?

When you lose your air conditioning do you lose all AC power to the boat or just to the air conditioning? Also have you instead of disconnecting the power cord have you tried just switching the panel circuit breaker off then back on? It should have the same effect as when you disconnect the cord.

While this is a problem that needs correction I wouldn't worry to much about fire since the power cord has circuit breaker protection at both ends, dock and boat.

[David Discenza]

David

I wonder if it could be an intermittent leakage between two poles, not actually a short or reversed polarity?
If there was a very low amperage leak between the hot and grounded (white) conductors then the RP bulb (between the white and green ground conductor) could light.

You might try cleaning up and spraying the faces of both cord ends with a dielectric and definitely check with a meter for any leakage between the three poles of your shore cable.

Are you talking about the receptacle on the boat into which I plug the shore power cord or the male and female ends of the shore power cord?

[David Discenza]

David : Knowing the boat, it might have been some spilled Irish Coffee!!   Smile - In Jest!!

A thought

Ron,
I'm not ruling anything out!

[David Discenza]

David,

You're boat (Mk 1.5) is fairly close to mine (Mk 1) so you may have the same electrical panel. My panel has three lights, two amber, one red and a circuit breaker just below. How do your lights normally indicate? My ambers normally flicker, one or both depending on where I'm hooked up at. When you get the red reversed polarity light what do your ambers do?

When you lose your air conditioning do you lose all AC power to the boat or just to the air conditioning? Also have you instead of disconnecting the power cord have you tried just switching the panel circuit breaker off then back on? It should have the same effect as when you disconnect the cord.

While this is a problem that needs correction I wouldn't worry to much about fire since the power cord has circuit breaker protection at both ends, dock and boat.

Gunner,
I have a green and a red light on the ac side of my panel. When everything is fine, I have a steady green light. When things go kaflooey, the amber light is lit and the green goes out.

When the red light comes on, all ac power is lost. I have tried just turning the master switch on the panel on and off with no effect. I have done the same at the master breaker which is in the port setee. No effect. If I disconnect the power cable, wait a few seconds, the reconnect it, the red light goes out and the green light comes on....until it goes out again.

[Ron Hill]

Guys : Catalina had the propensity to change the main electrical panel (at least in appearance) EVRY year.  In 1988 production was the 1st year they used circuit breakers and GFI protected AC electrical outlets (Bristol Marine).  The factory went to the smaller rocker switches and a new panel (Seaward) in 1989.  I believe that #1244 is a 1993 boat?

In my 1988 #788 - I have for shore power a double throw / triple pole / 30Amp breaker switch.  I know that if I run into reverse polarity the red RP light comes on and the breaker trips!!  I can not attest for later production!! 

I know the previous (original) owner of #1244 and know that he would never unplug the boat from shore power if anything inside the boat was ON AC power!! 

A few thoughts

[KWKloeber]

David

I'd make sure all the surfaces are clean so there's nothing there that could leak/conduct the slightest voltage from one pole to another.

I'd think if that was happening regularly I'd have my meter ready to pull the panel an test/verify there's actually a reverse goibg on to gain another piece of data.

Maybe a compromised cord?  Test that as well.

-k

David

I wonder if it could be an intermittent leakage between two poles, not actually a short or reversed polarity?
If there was a very low amperage leak between the hot and grounded (white) conductors then the RP bulb (between the white and green ground conductor) could light.

You might try cleaning up and spraying the faces of both cord ends with a dielectric and definitely check with a meter for any leakage between the three poles of your shore cable.

Are you talking about the receptacle on the boat into which I plug the shore power cord or the male and female ends of the shore power cord?