Fresh Water A/C pumps not bonded?

Carpediem44DB

Carpediem44DB

Well-Known Member
Aug 18, 2015
3,230
Sanfransico Bay area
Boat Info
2000 Carver 506
2006 44 DB Sedan Bridge
Engines
Volvo TAMD 74 P
I have always had an issue with water collecting in the center bilge and I noticed it is more pronounced when the A/C -Heat systems are operating. I assumed that it was the condensation form the condensers but realized now that the heat is being used, I get the same water intrusion. I finally decided to hunt down the source and have narrowed it to a leak in the water system to the aft systems. While troubleshooting I noticed that the A/C fresh water pumps/ motors are not bonded. I assume that since they are part of the AC system, they are grounded/bonded already so additional bonding is not required or even problematic. I understand the bonding system, but it gets fuzzy for me when it comes to the AC ground circuits.
Carpe Diem
 
Carpediem44DB said:
I have always had an issue with water collecting in the center bilge and I noticed it is more pronounced when the A/C -Heat systems are operating. I assumed that it was the condensation form the condensers but realized now that the heat is being used, I get the same water intrusion. I finally decided to hunt down the source and have narrowed it to a leak in the water system to the aft systems. While troubleshooting I noticed that the A/C fresh water pumps/ motors are not bonded. I assume that since they are part of the AC system, they are grounded/bonded already so additional bonding is not required or even problematic. I understand the bonding system, but it gets fuzzy for me when it comes to the AC ground circuits.
Carpe Diem
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"A/C fresh water pumps" - fresh water or sea water? Is your system hydronic or packaged units?
Regardless, if the pumps are for sea water, then they should be bonded unless they are magnetically coupled like hughespat57 says then they are isolated. But it never hurts to bond them anyways.
 
ttmott said:
"A/C fresh water pumps" - fresh water or sea water? Is your system hydronic or packaged units?
Regardless, if the pumps are for sea water, then they should be bonded unless they are magnetically coupled like hughespat57 says then they are isolated. But it never hurts to bond them anyways.
Click to expand...
Duh, I meant sea water for sure. There are two pumps, one for the two bridge systems and one for the four cabin and salon units. It’s just odd on this Carver how somethings are bonded and others are not. One of the pump motors is covered in rust with no paint left and one still has paint but is showing corrosion. The pump sections are bronze and are unpainted and showing corrosion. I was concerned if bonding the motor frames would perhaps develop a ground loop or something weird.
They work great so I’m going to remove them, clean them up and repaint them and go ahead and include them in the bonding circuit. They are about a foot away from the thru hulls that feed them and are bonded.
Carpe Diem
 
Sounds like they are Oberdorfer pumps - they definitely must be bonded.
IMG_5478.jpg
 
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Tom, what do you use to clean up the strainers and pumps? All of mine are green. Do you use a chemical etch of some kind and then a sealer or just Armstrong on a regular schedule?
 
Carpediem44DB said:
Tom, what do you use to clean up the strainers and pumps? All of mine are green. Do you use a chemical etch of some kind and then a sealer or just Armstrong on a regular schedule?
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I mix a solution of 10% pool acid (hydrochloric) and 90% DM water in a spray bottle. Spray it on the bronze dry until the bronze is completely saturated and let it set for about 10 minutes then rinse well sometimes have to brush with a sst brush. If it is bad then two applications. Then I mix baking soda with water and deluge the bronze and let it set to neutralize the acid the rinse well. Last time the boat was out I also rebuilt the strainers.
IMG_5472 cropped.jpg
 
Thanks Tom, that should make short work of that project for sure. I’ll post before and after pics. Getting this boat caught up the the shape I left my 44DB is proving to be a good second occupation ;)
 
ttmott said:
Sheech, I haven't seen my boat for a month.... And, it's only ten minutes from home.
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Well, judging from the pics you posted of your home remodel project, you get a pass:). Did the work get finished by the holidays like you were hoping?
 
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