Failed water pump ad sump query

You haven't said what sort of motor it is, but if it is a commutator motor with brushgear, the fault could be worn-down brushes to the point where one of them is almost-but-not-quite touching the commutator. Tapping the motor gives some sort of contact and then the vibration of the motor allows it to touch the commutator often enough to keep it running. This will give a fireworks display around the commutator and will do considerable damage if it continues.

If it is not a brush motor, a similar thing can happen if the terminals have become loose. The sudden shock torque as the motor starts is enough to make contact and vibration will keep it running; then the contact is lost again after the motor has stopped.

The first things you need to check are what type of motor it is and whether the supply is reaching the terminals in the connection box on the motor casing.

Well, not withstanding your thoughts, I would first be suspicious of well-worn (short) brushes.

Jonesy

The pump is a JTFS Mini Micro domestic sewage pumping station, probably JTFS190NN No type technical details found but no obvious external starter cap outside the motor casing or casig bulge. The other consideration is it was installed 10 years ago, tested working then, but never heard to be working since. It should have worked in a flood situation last year but it did not (automatically of its own accord that is) , no maintainece or testing or inspection in those 10 years by the owner or anyone else.

My BIL has a sump pump for his basement. It deals with any water penetrating, as well as the stuff from the toilet in the basement. It needed replacement, but that only cost around £70-80. Having seen that your one costs around £800, I can see why you are so interested in repairing it!

They are rated for AC only, so most unlikely to be a brush motor (which might also be too noisy in this application). If there is no visible capacitor, it could be an induction-start motor or the capacitor is hidden in the control box.

When it starts, is there s "snick!" noise as it reaches running speed? That would be a centrufugal starting switch throwing out - and when the motor is switched off, as it slows down, you might hear the switch go "Snick! " again as it resets.

That absolutely rules out any sort of wear-related pronlem. It would be the sort of situation where the starting switch contacts become corroded through lack of use. A slight tap causes them to make contact and the starting current (which is usually quite large) blows some of the corrosion away. After a few starts like this, you may find it appears to work properly.

If mild corrosion in the starting switch is the cause of the problem, testing it, say, once every couple of months should keep it healthy. If water has penetrated the casing, you will eventually have a much bigger problem - you need to check for that with a 500v tester, just in case.

We've looked into replacement rather than repair, seeing similar solids /dirty water capable combined pump and float switch. ToolStation and Machine Mart 70-120 squid but are trying to unravel submersible from submergible meanings as the counter staff don't know and such info not on/in the boxes. What was the failure process of your one?

It is protected by a RCCD/ELCB that has never tripped out over 10 years. But when I said tapping the motor, I used an insulated stick JIC. Next visit I'll take a plastic stethoscope to have a better listen for a cetrifugal switch, but i can see a corrossion or mechanical problem there giving the repeatable no-go/go on tap symptom.

I have no idea, I'm afraid! My BIL is completely non-technical. He 'got a man in', who told BIL to get a new pump.

BIL had the basement excavated about 20 years ago. AFAIK, he's only had one replacement pump since then.

What does the JT Pumps technical helpline suggest?

If it's a motor with brushes: I had a convertible, a car, and the motor to put the top up or down often would not start. I had to open the trunk and whack it with lug wrench to get it going and once going it was always enough for 1/2 cycle, up or down, but often didn't work for the next half-cycle. The longer this went on, the harder and the more times I had to hit the motor.

I decided it must be the brushes and the real hardware store I went to had a cabinet with several drawers and 20 or 30 sizes of brush. Somehow I knew the x-section and I bought 2 brushes.

When I got the motor out and apart, I had the right size brush, but the woven copper leads in the ones I'd bought were half or less of the x-section of what had been in there. I didn't think the new brush leads could take the current, because the frame for a full size convertible, or even a compact, is heavy, and the mechanical advantage isn't too good either for part of the travel, so the motor uses a lot of current. But the motor was out, I couldn't put the top up or down, and it was summertime.

So I got some tinfoil, which is USA talk for aluminum foil, from a roll used for cooking, wadded it up and stuffed it under the original brushes, without interfering with the springs that were already there, and my motor was good as new for years to come, until the rest of the car wore out. They still had plenty of length before they would be gone altogether, they just needed to be pushed against the armature, and the tinfoil took up about a half-inch. It took only one or two square inches for each, iirc. Except that I probably didn't return the brushes I'd bought, the whole repair cost 2 or 3 cents.

Better than 800 pounds!

I see that it has an 8m head. Tha tmeans it will lift the water that far, right? 26 feet!! Does BIL really need that much. It says it's good for sewage but says, if I read correctly, nothing about a macerator. Maybe it's good for sewage just because people with a toilet below grade need a pump. But in BIL's case, mMaybe the toilet itself is self-macerating, or maybe there is no toilet ) .

I have a sump pump that only has to lift the water about 8 feet, although it's probably rated a lot higher. Around here they sell them with 1/3 and 1/2 horsepower motors, the smaller one for under $40 or 50. Maybe that's all he needs? (I replaced mine once, with the same thing, 1/3HP. Once onlyu in 41 yers it could not keep up with the rain and the rain around the foundation, with corrugated perforated 4" plastic pipe leading to the sump inside the basement, flooded the basement a bit. I wish I'd bouht the 1/2 HP. )

So your BIL has a toilet in the basement, but doesn't use a special pump? Just a standard sump pump. Is the toilet self-macerating?

Good question! No, it's not.

After a few light taps to the body, normal centrifugal switch action returned . 10 on /off cycles without any tapping, just lifting the float switch . The owner will activate via lifting the float switch once a month from now on, hopefully will keep it free.

Very pleased to hear that. Regular maintanance works out a lot simpler than repair.

Have the owner buy a "water alarm": small box, 9 Volt battery, beeper -- makes a loud noise when wet. Very little money, under 10 Euros/dollars/pounds, Amazon, eBay, Aliexpress...

Fasten it in the sump suitably -- less likely for the water to sneak up on him...

Thomas Prufer

The problem is knowing whether the pump has actually worked unless you are around and hear it. I came up with a simple solution to that. A Lego brick tied to the outlet snorkel pipe with a bitofcord and the Lego flicked down into the snorkel tube. Any pump activity would soon chuck out the Lego

Nice solution!

The other problem is the water rising, and you don't notice it until it's too late, no pump, flooding, ...

Friend had a plumber in, who left such a water alarm after doing his work, as a gift. This had the plumber's name and number on it. Yeah, well, whatever...

Two months later it beeped, they went to investigate, and caught a (different) leak when it was still an easily manageable puddle... The plumber got repeat business.

Thomas Prufer

And I got mine at Home Depot. Inexpensive.