Hymer black tank macerator project (2 Viewers)

[DBK]

I would try it on EHU. My guess is possibly duff leisure batteries. The macerator is stalled due to the low voltage. Good batteries should be able to produce 28A without dropping to 7V. On EHU the charger should be able to hold a higher voltage and the macerator will then work.

 

[MisterB]

If your leisure battery is sh1t, don't attempt to dispose of it down the toilet .....


Seriously though, great thread! I also liked that someone mentioned toilets from boats have similar setups, though as with motorhoming, nothing on boats comes cheap!



Did you just keep all the silicone pipes connected to each other or did you add inserts of some sort as someone suggested?

 

[sallylillian]

Macerator motor problem, the volt drop and amp draw suggests something like motor brushes buggered but maybe its brushless. Either way my first try would be to replace the pump motor. Or it could be hair wound around the macerator blade jamming it? You do regularly clear that??

 

[DavidG58]

I would try it on EHU. My guess is possibly duff leisure batteries. The macerator is stalled due to the low voltage. Good batteries should be able to produce 28A without dropping to 7V. On EHU the charger should be able to hold a higher voltage and the macerator will then work.

Having similar thoughts, it’s five years since we replaced the gel batteries, but have now used Langtoftlad Stephens lithium brick device very impressed makes no difference to macerator operation

 

[DavidG58]

Did you just keep all the silicone pipes connected to each other or did you add inserts of some sort as someone suggested?

Still left as originally fitted except adding more bends and joints due to needing to lower the position worked fine for five years, at some point my luck to improve

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[funflair]

Macerator motor problem, the volt drop and amp draw suggests something like motor brushes buggered but maybe its brushless. Either way my first try would be to replace the pump motor. Or it could be hair wound around the macerator blade jamming it? You do regularly clear that??

Just had a quick look Michael (no tools involved ) the pump does indeed seem to be blocked/jammed in some way, it jumps when the power is applied but it doesn't spin.

 

[DavidG58]

Macerator motor problem, the volt drop and amp draw suggests something like motor brushes buggered but maybe its brushless. Either way my first try would be to replace the pump motor. Or it could be hair wound around the macerator blade jamming it? You do regularly clear that??

Consensus now is seized motor in macerator , but no never had had any desire to clean inside

As just posted by funflair , continued thanks Martin for your ongoing support of our Hymer odd that you are here for this next stage having helped diagnose more intimately that first macerator failure

 

[sallylillian]

Consensus now is seized motor in macerator , but no never had had any desire to clean inside

As just posted by funflair , continued thanks Martin for your ongoing support of our Hymer odd that you are here for this next stage having helped diagnose more intimately that first macerator failure

I had a set of long surgical clamps, with a slight bend. I used to check the blades after every use. Mine was a removable setup on the exterior evacuation connection. You do need to be prepared for the regular maintenance. I also carried a complete wired up spare. Just consider yourself as a mother with a newborn and you'll be fine.

 

[sallylillian]

Consensus now is seized motor in macerator , but no never had had any desire to clean inside

As just posted by funflair , continued thanks Martin for your ongoing support of our Hymer odd that you are here for this next stage having helped diagnose more intimately that first macerator failure

PS I did once have visitor who put a tampax down the loo, now those strings are a real pain to clear

 

[DavidG58]

Replacement ordered, next weeks project, most interesting difference only 9A hoping that might be reflected in Db levels, current one is particularly loud

Rv Motor Home 12V (12 Volt) Macerator Pump Mp3500 18590

Input Voltage DC 12v (12volt). Amps 9. Self priming. Thermal Overload, Automatic restart. Horizontal length discharge up to 106 meters (350 feet). Output flow 45L per min (12 US Gallons).

unifloproducts.co.uk

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[sallylillian]

Replacement ordered, next weeks project, most interesting difference only 9A hoping that might be reflected in Db levels, current one is particularly loud

Rv Motor Home 12V (12 Volt) Macerator Pump Mp3500 18590

Input Voltage DC 12v (12volt). Amps 9. Self priming. Thermal Overload, Automatic restart. Horizontal length discharge up to 106 meters (350 feet). Output flow 45L per min (12 US Gallons).

unifloproducts.co.uk

Out of interest what breaker/fuse have got protecting this circuit. Either should have cut out with that sort of problem. So I suspect either too large or not at all. Circa 20amp but check the manual for instruction.

 

[DavidG58]

Out of interest what breaker/fuse have got protecting this circuit. Either should have cut out with that sort of problem. So I suspect either too large or not at all. Circa 20amp but check the manual for instruction.

Very good point, the Hymer control board has a 25A fuse which we did blow with holding the on button too long when checking things

Just fitted new pump, actually swapped for one with different inlet fitting , Sureflo in Wakefield excellent knowledge and support

It only has a 7A pump compared 28A, but it only runs literally for a couple of seconds to empty the toilet bowl and is designed to empty black tanks

I am thinking of fitting a lower rated fuse

All good to go again, the alternatives were not much fun sadly lower Amps hasn’t appeared to reduce Db’s, but I think Bev would rather things vanished, even if noisily

It’s not that bad, but not tried listening from outside yet, away with family this weekend they will soon let us know

I have also taken out a bend, hoping the outflow from bowl will be easier now

Still taking my chances with the silicone hoses but having really struggled to get them apart even without jubilee clips and having done five years since fitting , I appear to have gambled well for a change

I have since photo wrapped it back up in an old cat blanket to helpfully cut down a bit more noise

 

[DavidG58]

It only has a 7A pump compared 28A, but it only runs literally for a couple of seconds to empty the toilet bowl and is designed to empty black tanks

Now the pump is out I have checked the label, it says to use a 20A fuse with a max designed draw of 15A

So the 28A seen on the Hymer controller and I think verified by Martins loop meter would suggest something was seriously wrong

I did try and get it apart but one screw is stuck solid, I can rotate the impellor but there is a rubbery squeak , I have now lost interest in it, think we now have a better pump and will add the old one to our scrap metal for the tip

 

[funflair]

Now the pump is out I have checked the label, it says to use a 20A fuse with a max designed draw of 15A

So the 28A seen on the Hymer controller and I think verified by Martins loop meter would suggest something was seriously wrong

I did try and get it apart but one screw is stuck solid, I can rotate the impellor but there is a rubbery squeak , I have now lost interest in it, think we now have a better pump and will add the old one to our scrap metal for the tip

You can wash your hand now then David

 

[DavidG58]

actually swapped for one with different inlet fitting , Sureflo in Wakefield excellent knowledge and support

Not too sure where I dreamt up their name

It is Uniflo

12V (12 Volt) Marine Macerator Pump Mp4500 18590 As Jabsco

Marine Macerator 12V Self Priming Seamless Motor Shell.O-Ring Shaft seal. Heavy Duty Shaft Seal. Innovative Internal Housing Design Dual Blade Design. Premium Impeller. Ignition Protection. Front waste inlet 1-1/2" or 38mm.Push Fit or BSP Thread. Side waste outlet 1" or 25mm.Push Fit...

unifloproducts.co.uk

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[Gromett]

It is Uniflo

Duoflo would have been more apt?

 

[Jev88]

Not sure if it useful but have you ever seen an RV external macerator set up?
I have a short concertina pipe from Y junction where great and black meet. Attach pipe down through locker and macerator sits on the floor underneath. Then 1"(?) Pipe in as many lengths as I want with snap joints. Reaches most elsan points and I have a remote 12V switch in my pocket so I can hold the nasty end securely.

 

[funflair]

Not sure if it useful but have you ever seen an RV external macerator set up?
I have a short concertina pipe from Y junction where great and black meet. Attach pipe down through locker and macerator sits on the floor underneath. Then 1"(?) Pipe in as many lengths as I want with snap joints. Reaches most elsan points and I have a remote 12V switch in my pocket so I can hold the nasty end securely.

you wouldn't want that getting away

 

[DavidG58]

Not sure if it useful but have you ever seen an RV external macerator set up?
I have a short concertina pipe from Y junction where great and black meet. Attach pipe down through locker and macerator sits on the floor underneath. Then 1"(?) Pipe in as many lengths as I want with snap joints. Reaches most elsan points and I have a remote 12V switch in my pocket so I can hold the nasty end securely.

I think the pump I now have would do that same job, plus boat tanks

Our issue is we need to macerate into the black tank then out by gravity , although I could attach a similar pump and pump away to an elsan, double blended

 

[Jev88]

you wouldn't want that getting away

If I was evil and someone upset me I could have a great time spray painting a neighbouring MH

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[Coastal Cruiser.]

Not sure if it useful but have you ever seen an RV external macerator set up?
I have a short concertina pipe from Y junction where great and black meet. Attach pipe down through locker and macerator sits on the floor underneath. Then 1"(?) Pipe in as many lengths as I want with snap joints. Reaches most elsan points and I have a remote 12V switch in my pocket so I can hold the nasty end securely.

Similar to my “must have” set up I’ve used once and that was a test on my drive
Most everywhere I have been in over 2 years has had drive over waste dump so never had to get it out
Have about 60m of hose also!!

 

[TheBig1]

I think your excess noise is vibration because it is not mounted securely with rubber isolators. The pump is usually screwed down flat and the outlets and inlets plumbed from there. You would need to create a support frame, otherwise the vibration on the pipes will cause a right racket

I took a look at a macerator toilet a friend had installed in his attic which was noisy enough to wake the house at night if flushed. The pipework was loose and allowed to vibrate. Some proper clamps solved it. Mind you I went ott and put more than needed but it fixed the noise with a few hours of work