Macerator with 100% Duty Cycle

[howson]

The recent conversation about macerators (https://gdrvowners.com/forum/operati...-in-2022-260rd) brought to mind a limitation with the Flojet 18555. Specifically I do not like the duty cycle limitation. From the Flojet's manual: Do not run more than 15 minutes continuously.

So my question to the forum is this: do you have a portable macerator that does not have a duty cycle limitation and if you do, what good (and bad) aspects can you report on the component?

Thanks in advance,
Howard

[Paul & Deb]

I'm interested in this as well. I use my Flojet regularly. Maybe someone could check out what is used in units with built-in macerators. Are they also Flojets? I've seen them on motorhomes and a few higher end trailers but never looked at who the manufacturer is.

[Jlawles2]

howson , Howard there is a write up on the internet somewhere that a creative person did converting a garbage disposal from a kitchen sink into a Macertor. Now it's not 12V but duty cycle is a lot more than 15 minutes. Neighbor after Harvey would put ice bags around his motor to get a longer run time. Me, I would pump for 10-15 minutes. go do something else for 15 min, and then repeat. My biggest issue was length of run. I had 150 ft of 1/2" hose that had developed a few un repairable deformations. Had the line been 3/4" it would not have been an issue as the macerator pumps a lot of water.

I'll send you a link b/c it's to another RV forum.

[Yoda]

howson Paul & Deb Jlawles2
OK - Yoda will ask the question so others do not embarrass themselves. I know Howard is wanting me to spend more money, along with others I wont mention.

But..........
Why should you have a " Macerator".?

This time I will go hide somewhere

Keith

[howson]

Why should you have a " Macerator".?

Using a macerator is yet another way to deal with RV issues that I "stole" from Cate&Rob . I'll let him explain the process, but you can get a good summary here: https://gdrvowners.com/forum/operati...ater-to-a-tank

Howard

[Cate&Rob]

A "macerator" pump has a chopper blade because it is designed to pump black tank contents through a garden hose. I only ever used mine for grey tank water as explained in the link in post #5. I don't recall a duty cycle caution, but it will pump the contents of a grey tank into the tote in the back of the truck in less than two minutes . . . so, duty cycle was never a concern.

Rob

[howson]

Perhaps a clarification of the requirement is in order.

When I'm at my daughter's the black and gray contents are pumped from where the trailer is parked to the cleanout connection outside their home. It's quite a distance but it works. Dumping all at once (all the tanks) is more than the macerator can pump in one session, so it's a nuisance to 1) wait or 2) do often. I want to hook up only as needed and drain all the tanks completely in one session without worrying about the pump overheating.

FYI when the contents get to the stinky slinky gravity does the rest of the work getting the contents into the sewer drain.

[Cate&Rob]

The macerator pump "kit" that I have, comes with an expandable hose shown in the attached picture. This is a larger diameter than a garden hose and extends to about 15 ft. Through this hose I can completely empty a single holding tank in less than two minutes. This means that I could probably empty all three holding tanks in something like six minutes. Perhaps a larger diameter hose would solve the duty cycle issue by emptying the tanks faster with less back pressure.

Rob

[howson]

Cate&Rob -- what is that connection at your macerator discharge port? The Flojet 18555's discharge port is a garden hose connection that can't be modified. Unless there's an adapter I'm not aware of?

[ncitro]

I know with my Flojet it recommended a 3/4" discharge hose rather than 1/2 or 5/8. At home I have a 3/4" hose dedicated for the purpose but it's quite long and I don't carry it. On the road I carry the orange Rhino 5/8" 25' hose (mainly because it's orange and it makes it easy to keep it separate). I pretty much only use it to drain grey and galley into my 42 gallon tote. I've never hit the duty cycle emptying 42 gallons, but I could see it if I was doing both grey's and possibly the black in one sitting.

Camco 22990 25ft RhinoFLEX 5/8" ID Gray/Black Water Tank Clean Out Hose | Ideal For Flushing Black Water, Grey Water or Tote Tanks , Orange https://www.amazon.com/dp/B06XGW1NGD...MR8HZZKAVYVRBN

[Jlawles2]

howson Howard, I think the flow jet is rated at something like 6 GPM. At the time we were staying in the camper semi full time (flood repair in our driveway on weekends), I was leaving the grey tank open until it was time to dump the black, then I would build clean out water in the grey. I pumped down the black, flushed with the grey, then back to gravity draining the grey. This was in the 23' bumper pull, so the tanks were not that big.

[howson]

Jlawles2 -- the Flojet's manual does not have a GPM rating, but it does state, "Empties a typical 40-gallon holding tank in less than 5 minutes.". That's 8 GPM but I've never tried to measure it. I'd guess that it depends on how much back pressure is introduced (i.e. how far and how much elevation gain is in the discharge path).

[Cate&Rob]

Cate&Rob -- what is that connection at your macerator discharge port? The Flojet 18555's discharge port is a garden hose connection that can't be modified. Unless there's an adapter I'm not aware of?

The macerator pump that I have is probably 8 years old and has just a straight outlet (probably about 1" . . . but at home so I can't measure) with the hose held in place with a hose clamp. I cannot find in anywhere online.

You could determine whether the hose is a factor by pumping directly from the pump into a five gallon pail and then connect the hose and filling the pail from the end of the hose. A significant difference in time to fill the pail would be a measure of flow restriction caused by the hose.

Rob

[Jlawles2]

Cate&Rob Rob, is this the one you have? https://www.hodgesmarine.com/flj1855...xoCedMQAvD_BwE

13 GPM

[Cate&Rob]

Cate&Rob Rob, is this the one you have? https://www.hodgesmarine.com/flj1855...xoCedMQAvD_BwE

13 GPM

That could be the one. Mine came from an RV store as part of a “kit”. I will be home in a couple of weeks and will take a closer look. The pump came with that home made looking bracket and switch . . . just like in the picture.

Rob