Shore Power Ground ??'s

[Matt Cawthorne]

Larry,
I too have one of these sensors, but it is another brand. I think that they are the way to go. The boat has two. One set to run the bilge pump and one set at about 18 inches which will trigger an alarm. The switches and wires stay nice and dry. I may decide to replace the plastic hose now and again in case any goo from the bilge will build up and clog it, but it is a far better way to go than to be replacing wires.
My approach to dealing with water in the boat while away is to close all seacocks except the cockpit drains. I would rather rely on a seacock than a bilge pump. I am more afraid of a fire from the electrical system than from flooding. This way one is certain that all seacocks work freely each and every trip.

Matt

Hi Dave,

Yup. read your account about the head running over. We have had this happen too..while aboard thank goodness.

I decided to put in an electric bilge pump (had none for 7 years..really stupid of me!), but did not like the idea of putting a water detection switch in the bilge, where things are occasionally rather messy. I found exactly what I was looking for. An externally mounted, inexpensive bilge water switch. It' s made by Groco, and is a rubber diaphram with a manually adjusted microswitch built into the sensor. The whole thing is enclosed in anodized aluminum. The principal operating theory is that there is a small plastic tube (similar to aquarium air line tubing) going down into the bilge. The end is connected to a small round bell-shaped part. This traps air in the tube. WHen the water rises more than 3 inches, it activates the microswitch (this turn on point and also the span between on-off are adjustable from the engine compartment), which turns on the pump motor. The sensor itself stays clean and dry, and the sensor is only 1 inch in diameter, so it can be mounted anywhere. Incidently, this is the same method used by the motor control companies to determine pump turn on/off points with sewage pits and lift stations.

These are available from West Marine and Defender for certai, and cost around $40.

Cheers!

Larry DeMers
s/v DeLaMer
Cape Dory 30

Larry & Bill,


Larry, your point about the bilge pump is good. I think you read awhile ago here that Hanalei suffered an open head seacock incident that an automatic bilge pump would have saved. Unfortunately, my bilge pump switch is broken, and I still haven't replaced it, so the standby capability of the 120v battery charger is a mote point. I only use the bilge pump with a manual switch. I guess anything can happen at sea or at the dock, but one thing I do do know is that now, before leaving the boat, everything is checked secure!

mcawthor@bellatlantic.net

[Larry DeMers]

Hi Matt,

Good Move! good idea too..having two sensors, with one signifying high water. I too close all seacocks when we leave the boat for any time..except for the cockpit drains of course. I suspect that you will not have to replace the plastic tubing too often, since no water goes into the tube at all..just air. The increase in water depth increases the water pressure in the plastic tube, which operates the microswitch at the preset pressure. But there is no water in the tube itself. So that makes this a maintenance free system.
One thing I have had problems with however, is the microswitch sticking in the on position..happened once so far (I have a counter on the pump switch). This could burn the pump out if it was running dry for a long period. I need to determine if the sensor needs replacement. Have you had any problems with this type of problem?
What brand is your sensor??

Cheers,


Larry DeMers
s/v DeLaMer
Cape Dory 30

Larry,
I too have one of these sensors, but it is another brand. I think that they are the way to go. The boat has two. One set to run the bilge pump and one set at about 18 inches which will trigger an alarm. The switches and wires stay nice and dry. I may decide to replace the plastic hose now and again in case any goo from the bilge will build up and clog it, but it is a far better way to go than to be replacing wires.
My approach to dealing with water in the boat while away is to close all seacocks except the cockpit drains. I would rather rely on a seacock than a bilge pump. I am more afraid of a fire from the electrical system than from flooding. This way one is certain that all seacocks work freely each and every trip.

Matt

Hi Dave,

Yup. read your account about the head running over. We have had this happen too..while aboard thank goodness.

I decided to put in an electric bilge pump (had none for 7 years..really stupid of me!), but did not like the idea of putting a water detection switch in the bilge, where things are occasionally rather messy. I found exactly what I was looking for. An externally mounted, inexpensive bilge water switch. It' s made by Groco, and is a rubber diaphram with a manually adjusted microswitch built into the sensor. The whole thing is enclosed in anodized aluminum. The principal operating theory is that there is a small plastic tube (similar to aquarium air line tubing) going down into the bilge. The end is connected to a small round bell-shaped part. This traps air in the tube. WHen the water rises more than 3 inches, it activates the microswitch (this turn on point and also the span between on-off are adjustable from the engine compartment), which turns on the pump motor. The sensor itself stays clean and dry, and the sensor is only 1 inch in diameter, so it can be mounted anywhere. Incidently, this is the same method used by the motor control companies to determine pump turn on/off points with sewage pits and lift stations.

These are available from West Marine and Defender for certai, and cost around $40.

Cheers!

Larry DeMers
s/v DeLaMer
Cape Dory 30

Larry & Bill,

Larry, your point about the bilge pump is good. I think you read awhile ago here that Hanalei suffered an open head seacock incident that an automatic bilge pump would have saved. Unfortunately, my bilge pump switch is broken, and I still haven't replaced it, so the standby capability of the 120v battery charger is a mote point. I only use the bilge pump with a manual switch. I guess anything can happen at sea or at the dock, but one thing I do do know is that now, before leaving the boat, everything is checked secure!

demers@sgi.com

[Matt]

Larry,
I do not remember the brand of my sensor/switch. It is a unit which is about 2 inches in diameter, less than 1 inch high and has a yellowish color which is probably cadmium. To date my units have been trouble free. I flood the bilge a couple of times per year to check the alarm so it does not see much service, but the other has worked well under normal operation for 2 1/2 years. My boat is relatively dry so the only water that the bilge pump needs to remove under normal circumstances is melted ice from the icebox. I hope to re-route the icebox drain through a pump to the sink drain to eliminate even this source of water.....someday.

Matt

Hi Matt,

Good Move! good idea too..having two sensors, with one signifying high water. I too close all seacocks when we leave the boat for any time..except for the cockpit drains of course. I suspect that you will not have to replace the plastic tubing too often, since no water goes into the tube at all..just air. The increase in water depth increases the water pressure in the plastic tube, which operates the microswitch at the preset pressure. But there is no water in the tube itself. So that makes this a maintenance free system.
One thing I have had problems with however, is the microswitch sticking in the on position..happened once so far (I have a counter on the pump switch). This could burn the pump out if it was running dry for a long period. I need to determine if the sensor needs replacement. Have you had any problems with this type of problem?
What brand is your sensor??

Cheers,


Larry DeMers
s/v DeLaMer
Cape Dory 30

Larry,
I too have one of these sensors, but it is another brand. I think that they are the way to go. The boat has two. One set to run the bilge pump and one set at about 18 inches which will trigger an alarm. The switches and wires stay nice and dry. I may decide to replace the plastic hose now and again in case any goo from the bilge will build up and clog it, but it is a far better way to go than to be replacing wires.
My approach to dealing with water in the boat while away is to close all seacocks except the cockpit drains. I would rather rely on a seacock than a bilge pump. I am more afraid of a fire from the electrical system than from flooding. This way one is certain that all seacocks work freely each and every trip.

Matt

Hi Dave,

Yup. read your account about the head running over. We have had this happen too..while aboard thank goodness.

I decided to put in an electric bilge pump (had none for 7 years..really stupid of me!), but did not like the idea of putting a water detection switch in the bilge, where things are occasionally rather messy. I found exactly what I was looking for. An externally mounted, inexpensive bilge water switch. It' s made by Groco, and is a rubber diaphram with a manually adjusted microswitch built into the sensor. The whole thing is enclosed in anodized aluminum. The principal operating theory is that there is a small plastic tube (similar to aquarium air line tubing) going down into the bilge. The end is connected to a small round bell-shaped part. This traps air in the tube. WHen the water rises more than 3 inches, it activates the microswitch (this turn on point and also the span between on-off are adjustable from the engine compartment), which turns on the pump motor. The sensor itself stays clean and dry, and the sensor is only 1 inch in diameter, so it can be mounted anywhere. Incidently, this is the same method used by the motor control companies to determine pump turn on/off points with sewage pits and lift stations.

These are available from West Marine and Defender for certai, and cost around $40.

Cheers!

Larry DeMers
s/v DeLaMer
Cape Dory 30

mcawthor@bellatlantic.net

[John]

A lot of responses and a lot of opinions. I have one question for those advocating the advice of the West Advisor, ABYC, US Power Squadron viewpoints of a "floating AC system" of not running the 110v ground (green) to the ships common ground point. That may be (I emphasize - "may be") okay if you are at the dock and connected to shore power and all connections are in perfect condition. But no one discusses the use of an inverter or generator while away from the dock. Where is the safety ground? What happens when you are using a generator or inverter and an appliance you are using shorts out and your AC ground wire isn't connected to ground because you don't have a shorepower cable plugged in? Oh,.... no problem it's connected to the generator or inverter case which is connected to the ships ground so everything is okay and everyone's safe, right? Well that's the same as connecting the AC ground to the common ground point. I think anyone that doesn't run the AC ground (green) wire to the common ground point is nuts. Our boat is plugged into shore power around the clock, battery charger is always on in case the bilge pump comes on in an emergency. This boat is loaded with electrical equipment of all types. She is wired using the COMMON GROUND POINT method for all electrical systems. She has been plugged into shore power continually around the clock for many years, since 1983 in fact. She is only unplugged when she is sailed. This boat has never had any electrolysis problems nor have any neighboring vessels when she was berthed for three years at a marina. She is currently berthed at a private dock. Over her years she has been connected to many different shore power hook ups and has never had a problem. This is real world experience and not a bunch of tossed around theories. I realize there are equally real world horror stories and I have seen some fairly significant ones first hand. Every problem I've witnessed with leaving AC on is due to very shody wiring practices by amateur electricians. In my book priority goes to the safety of those on board using AC appliances, period.

[Larry DeMers]

John says ".... That may be (I emphasize - "may be") okay if you are at the dock and connected to shore power and all connections are in perfect condition. But no one discusses the use of an inverter or generator while away from the dock. Where is the safety ground? What happens when you are using a generator or inverter and an appliance you are using shorts out and your AC ground wire isn't connected to ground because you don't have a shorepower cable plugged in?"....etc.

..First of all, realize that you are not the only person with experience. I have 30 years sailing experience, 35 years as an electrical engineer, and I sail around 1000 miles a year. My viewpoint comes from experience also.

If you use a generator or inverter (I do), the green safety wire is wired to the case of that device also, since it uses the 120VAC for it's operation, and you would want to have a short from either L or N to be bridged to safety ground, ***which will trip the breaker, opening the circuit, saving your life***. It works.

In my book also, priority goes to the safety of those aboard the boat using landlubber appliances (those running on 120vac). As an aside..I do not understand the imperative of using household appliances aboard a sailing vessel. Certainly occasionally, a palmsander is handy etc. But microwaves, washmachines, blenders etc. belong in the home..not aboard a boat of the sizes that we are dealing with here.

Nothing at all is gained in safety or functionality by grounding to the engine. Just because you have been uncommonly lucky in berthing in marinas that have taken care of their docks and wiring does not make this a universal condition to be found by all sailors. Be careful of standing too hard on a position that has really no merit other than *opinion*. ie; what does connecting the green wire to the engine buy you that the floating ground does not?

Some sailors seem to latch onto a belief and ride it to hell, when a wise person would consider the opinions of others if there was sufficient volume expressing a dissenting opinion. I say 'consider', not accept. A closed mind is an old mind. It does not grow.

Larry DeMers
s/v DeLaMer



demers@sgi.com

[Walt Bilofsky]

Just to complicate the matter a little more - our power panel has reverse polarity indicators and a warning not to leave shorepower connected if the indicators light up. Dunno what the risk is - but they seem real insistent so I assume it's a safety issue. Presumably it doesn't happen unless the marina (or the boat) is mis-wired.

Also, I have seen a number of recommendations to install a galvanic isolator in the ground lead to reduce electrolysis. The ones in the West Marine catalog are real expensive, but I put in a much cheaper (probably earlier) model some years back. Can't say I saw much effect from it, but I don't think corrosion is much of a problem in my marina to begin with.



bilofsky@toolworks.com