Holding tank Macerator

Jim and Jackie

Well-known member
Joined
Nov 17, 2016
Messages
143
Fluid Motion Model
C-288 C
Hull Identification Number
FMLT2930C010
Vessel Name
Chessie
Our R29 has the macerator option for the holding tank. It looks like all you have to do to turn it on is flip the rocker switch on the DC Panel to on. If it is inadvertently turned on and the thru hull is closed you could get a bilge of “black” water. Am I missing something? Has anyone else worried about this? Or are there solutions?

On my sailboat there are several steps before the macerator can be turned on. Rather than rocker switches the panel has circuit breakers and there is a cover over the macerator switch, which it makes it hard to inadvertently turn it on. There are also a second on/off switch on the holding tank and a “Y” valve that needs to be switched from the deck pump-out fitting to the macerator.


Jim Demerest
R 29 Chessie
 
You are correct. You must open the thru hull valve before pumping. We used a label maker to make a warning label next to the rocker switch.
 
I understand how the system works. The question is has anyone come up with a “fail safe” way of preventing an inadvertent turning on the rocker switch when the thru hull is closed. A simple, if not legal, way is to always leave the thru hull open. The rocker switch could be moved to a less accessible place, you should only be pumping overboard outside of the 3 mile limit or… Another thought is to add a second switch is series with the rocker switch. Just looking for ideas. Maybe I’m paranoid but eyesight and 6 year olds can cause problems.

Jim Demerest
R 29 Chessie
 
I'm not that familiar with the layout since I only take delivery of my boat a few weeks from now but since you have scared me I will be looking at installing a momentary push and hold switch near the valve. I'm not sure how difficult it would be to change the existing rocker switch to a push and hold type.
Mark
 
Not exactly sure how blackwater would end up in the bilge if the macerator switch is activated and the Y valve is in a closed position.

When the macerator is activated and the Y valve is closed, the material doesn't have anyplace to go. I have turned on my macerator without opening the Y valve (forgot) and the pump just ran. No blackwater anywhere.

The pump is loud enough that you would certainly hear it from any position on the boat. So if your intent is not to be macerating / discharging you would immediately know to shut it off.
 
Agree it shouldn't happen. But, there is a possibility that the hoses could leak under pressure. Talked with Pocket Yacht this morning and we are going to put a key switch in series with the rocker switch. That meets my requirement that it be a positive action and not something that could happen unintended.

Jim Demerest
 
There is no black water pressure as the macerator is beyond the Y valve. It would just be pumping air or maybe a little black water left in the line. Not good for the macerator to run dry for very long but there shouldn't be any significant pressure.
 
On the 2016 R31S it is not a Y valve. I don't think there is a pressure problem or any where for the black water to go. BOY is that pump loud, I can't imagine turning it on and leaving it on without realizing it. In some coastal jurisdictions you had better have that valve closed or you may get cited. I do not believe this is a problem.
 
On our 2011 R29 the valve is behind a panel at the end of the cave. It would be easy to install some sort of switch there so when you close the valve you could also break the electrical connection. The valve on my 29 is after the macerator so a possible poop shower would be conceivable if a connection or pipe failed under pressure. Where it is I think if that happened you would have to just sink the boat as you would never get it cleaned out.
 
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