displacement pumps, like those with a rubber impeller and on your engines and generator raw water circuit, don't require priming. Centrifugal pumps, like those in an AC pump, do require priming.
"Burping" the AC ... ???
- Thread starter charlieft
- Start date
- Oct 12, 2006
- 1,974
- Boat Info
- "On Vacation"
2006 40 Sundancer
Raymarine E125 & HD Radar + Garmin 5208
- Engines
- QSB5.9 380 Cummins
http://en.wikipedia.org/wiki/Centrifugal_pump
Gary, did you delete the 'Lack of Prime' page above..? Now we'll never know the answer..
Gary, did you delete the 'Lack of Prime' page above..? Now we'll never know the answer..
CAMELLA
Active Member
So when I get back to my dock I can leave both(AC & genny) seacocks open when I lift the boat out of the water. When I lower the boat in the water the genny will prime itself and the AC I would have to disconnect the discharge hose and remove all the trapped air or bring the boat up on plan to prime the unit. Agree???
I'm not familiar with the location of the AC pump on a 340. The generator, however, will self prime as long as the rubber impeller in the pump is in good shape.
Just as a note, if a centrifugal pump (like an AC pump) is below the waterline, it should self prime. I'm assuming that on some Sea Rays the pump is not below the waterline and that causes a problem with prime... (or they have crazy hose routing that causes them to hold air).
Just as a note, if a centrifugal pump (like an AC pump) is below the waterline, it should self prime. I'm assuming that on some Sea Rays the pump is not below the waterline and that causes a problem with prime... (or they have crazy hose routing that causes them to hold air).
CAMELLA
Active Member
Thanks for the info!
MExcelsior
Member
Your right on the money..... ! The AC should in theory prime itself if the pump is correctly installed below the waterline. My 280 primes itself. However, both of my cruisers (AC) did and do require a quick spring priming. Even if the system sits below the waterline, there is a lot of air in the strainer, pump, system to purge after the winter layup.
Henry Boyd
Well-Known Member
- Apr 24, 2007
- 6,014
- Boat Info
- ‘09 Sabre 38 Hardtop Express “Serenity”
- Engines
- Volvo D6 w/IPS450 Pods
Mexcelsor,
That's interesting because my AC won't self prime. The pump on the 02 280 is mounted below the shelf the water tank sits on and is below the water line. Must be the plumbing.
The first year we had it, I did the remove the outlet hose and open the seacock thing. Then I picked up on the "just drive it" approach and that has worked for the past two years.
Henry
That's interesting because my AC won't self prime. The pump on the 02 280 is mounted below the shelf the water tank sits on and is below the water line. Must be the plumbing.
The first year we had it, I did the remove the outlet hose and open the seacock thing. Then I picked up on the "just drive it" approach and that has worked for the past two years.
Henry
Woody
Well-Known Member
Last year I put the boat in late in the afternoon and it sat till the next day. For the heck of it I turned on the AC and it had self primed overnite. I usually just take it for a ride and that would do it. I tried the hose thing also and that works but its hard for me to hang of the side of the dock and keep the hose firmly against the hull fitting.
MExcelsior
Member
Hi Henry,
There have been a couple of times that I too had to get on plane to prime, but not often. My pump is located below that shelf also, where the generator sits. (We moved the water tank to the starboard to accommodate the genset). I'm wondering if the weight of the twins would make a skosh difference in how the boat sits in the water. Who knows?...Maybe the successful self-priming of the ac pump is directly proportional to a full tank of gas, water and waste. : )
Michael
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