Manual macerator switch not working

[Sheepsations]

On our master switchboard, there is a switch to operate the macerator manually. When I flick the switch to the 'on' position, it automatically flicks back to the 'off' position and we can't get the macerator pump to operate.

I've tried finding a fuse for the macerator pump but no success.
Any ideas what the basic problem would be why the switch automatically flicks back to the off position when we try and use it?
Thanks in advance,

JR

[James S]

The switch you refer is the circuit breaker.. it takes the place of a fuze..
The reason it keeps switching off is that its telling you there is a problem and that is generally to much resistance.. it is "tripping" most probably the pump has a short or is stuck.
You should look at the pump directly most probably it will need to be replaced ..

[Sheepsations]

Thanks for that James.
Would a blockage in the pipes leading to the macerator or in the macerator itself have the same effect on the switch not working?

Thanks,

JR

[James S]

It sure would... almost certainly what has happened is the blockage is preventing the macerator pumps impeller from turning...
I'm guessing it may have been some time since it was used?

Its good practice to pump out your holding tank (and i would add rinse) before leaving it for any length of time.

[Sheepsations]

No I don't think it has been used in a while.
It looks like I know what I am doing this afternoon now........
Thanks for your help. I will follow your advise.

JR

[James S]

Good luck with it...

[Sheepsations]

One last question. It's Sunday afternoon here and the black water tank is full. There is no chance to get it pumped out until tomorrow at the earliest.

If I take off the hose between the tank and the pump to look for a blockage, do you think I will encounter a fountain of black water? There's already a bit of an overflow problem so I have to deal with some blackwater anyway with a sponge, gloves and bucket.

(I should add at this point, it's not my boat. I'm acting as skipper while the owner is o/s. Maintenance it seems is not his strongest point).

I'm prepared to have a go as I just want this problem fixed.

What do you think?
JR

[James S]

Is there no shut off valve between the tank and the pump?
I would absolutely expect there to be a big mess if you open it..
I would expect that the repair of the pump would be a non starter.. given the cost of a new pump, I would have it on board before starting ....
Is there some reason you need to tackle this today and not wait until tomorrow?
Have you checked to see if there is a spare pump on board?.. we always carry a spare.. its not unusual..

[Sheepsations]

Hmmmm, sounds ugly. I think I will wait till tomorrow and get it pumped out first!

[James S]

I would say thats a real good idea ..., if possible try and run a bunch of water in the tank after the pump out.. maybe let it sit or otherwise agitate it to loosen up whatever may be the problem... then try the pump again... I admit this is a very long shot... but if it works well worth the effort.. .. of course if it doesn't you'll need to pump out the tank again...

[Bill O]

If it's like one of these macerator pumps, they are notorious for eventually locking up/failing.


We replaced ours a while back with one like this and works well with reduced power consumption also.


Bill O.

[ranger58sb]

Sheep...

Sometimes you can free up a stuck macerator by manually rotating the impeller "axle". See if there's a slot for a screw driver of some sort, or maybe a nut for a socket, and have a go at that; crank it a bunch, back and forth, then see if the breaker will activate the pump. You might get lucky...

I gather from your login name that you're in Oz? FWIW, pumping overboard here in the U.S. while inshore would be a no-no...

-Chris

[jmschmidt]

As mentioned the "switch" you refer to is most likely a combination circuit breaker and switch. Most likely the grinders or blades of your macerator are stuck together with solidified "you-know-what" and toilet paper. Or, possible it's stuck and you burned the motor out by trying to force the breaker/switch to stay on. Your must remove the pump/macerator assembly and clean the blades thoroughly and test the motor before reinstalling. Your should exercise this unit by test running it every so often when on the boat even if the head has not been used. If direct discharge from the holding tank or head, run and circulate water for a minute or so. If your system has pump-out capability add a couple of gallons of fresh water, and running the unit and pump out.

[a64pilot]

Originally Posted by ranger42c

Sheep...

Sometimes you can free up a stuck macerator by manually rotating the impeller "axle". See if there's a slot for a screw driver of some sort, or maybe a nut for a socket, and have a go at that; crank it a bunch, back and forth, then see if the breaker will activate the pump. You might get lucky...

This, before you do anything else, usually there is a slot in the pump shaft that sticks out that a screwdriver will fit into.
Then once you get it working, you should bump that switch every week or so and make the pump move just a little.
One of the macerator pumps comes with an electronic control box that does just that, bumps the pump ever so often.

[Mike Banks]

Running a master switch to a panel seems strange to me because my heads macerator was run from the same auxiliary battery that supplied the anchor windlass. It did however connect to a 30 amp relay which switched on the macerator/pump--so the little flush switch on its neat little box only drew a couple of amps. The 30 amp relay switched the 15 amps the motor drew through its own platinum contacts. In over eight years I replaced the heads once--but never the switching.

I suspect you have an obstruction in the pump--and visitors aboard often have no idea that some items should never be disposed of in a marine head.

As for the wiring of same, why would one run such a long length of 15 amp capable twin wire from the heads to a master panel? It would require at least 6 mm diameter wire to do that--and then probably not well.

There is WAY too much extraneous wire cluttering the average boat. If you must use a master switch to isolate the heads--use a proper isolating switch capable of carrying 100 amps. They cost about fifty bucks. Mount it in the local lead from the master bus-bar to the heads motor directly just besides the operating switch for the flush/macerator..

I only have a few things connected to a master panel. None of them are engine controls, none of them are essential circuits, (only manual overrides). The two isolating switches for the battery banks have their position BEFORE any master panels are involved--and are situated below the master panel. They are only ever used when the vessel is out of the water, or when an auxiliary battery takes over while maintenance or replacement of batteries takes place. There are two covered terminals for the connection of such a temporary supply, on the panel side of the master switches, a battery which in my case came in the form of a portable rechargeable engine-start pack. It would run gas detectors and bilge pumps, water supply, radios and nothing else, for the hour or so I nedded to do any essential maintenance or replacements..