Failed water pump and sump query

[N_Cook]

Only made a preliminary check o this 1KW pump and float switch in a
sump, prior to dismantling ad exploring further.
Sump full of water but no pump action. Moving the float about made no
differece. Tapping the pump casing made the pump work until the float
switch dropped to the cut off point.
Refilling the sump and again no pump action until tapping the casing and
again stopping properly. I cannot see what in the way of sticky motor
brush or loose/corroded contact inside the motor housing could produce
this symptom.

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.

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.

[GB]

Post by N_Cook

Only made a preliminary check o this 1KW pump and float switch in a
sump, prior to dismantling ad exploring further.
Sump full of water but no pump action. Moving the float about made no
differece. Tapping the pump casing made the pump work until the float
switch dropped to the cut off point.
Refilling the sump and again no pump action until tapping the casing and
again stopping properly. I cannot see what in the way of sticky motor
brush or loose/corroded contact inside the motor housing could produce
this symptom.

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.

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!

[N_Cook]

Post by GB

Post by N_Cook

Only made a preliminary check o this 1KW pump and float switch in a
sump, prior to dismantling ad exploring further.
Sump full of water but no pump action. Moving the float about made no
differece. Tapping the pump casing made the pump work until the float
switch dropped to the cut off point.
Refilling the sump and again no pump action until tapping the casing and
again stopping properly. I cannot see what in the way of sticky motor
brush or loose/corroded contact inside the motor housing could produce
this symptom.

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.

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!

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?

[GB]

Post by N_Cook

Post by GB

Post by N_Cook

Only made a preliminary check o this 1KW pump and float switch in a
sump, prior to dismantling ad exploring further.
Sump full of water but no pump action. Moving the float about made no
differece. Tapping the pump casing made the pump work until the float
switch dropped to the cut off point.
Refilling the sump and again no pump action until tapping the casing and
again stopping properly. I cannot see what in the way of sticky motor
brush or loose/corroded contact inside the motor housing could produce
this symptom.

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.

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!

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?

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.

[micky]

In sci.electronics.repair, on Mon, 3 Feb 2025 19:31:25 +0000, GB

Post by GB

Post by N_Cook

Only made a preliminary check o this 1KW pump and float switch in a
sump, prior to dismantling ad exploring further.
Sump full of water but no pump action. Moving the float about made no
differece. Tapping the pump casing made the pump work until the float
switch dropped to the cut off point.
Refilling the sump and again no pump action until tapping the casing and
again stopping properly. I cannot see what in the way of sticky motor
brush or loose/corroded contact inside the motor housing could produce
this symptom.

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.

The pump is a JTFS Mini Micro domestic sewage pumping station,
probably JTFS190NN

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. )

Post by GB

Post by N_Cook
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

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?

Post by GB
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!

[GB]

Post by micky

Post by GB
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

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.

Post by micky

Post by GB
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!

[N_Cook]

Post by N_Cook

Only made a preliminary check o this 1KW pump and float switch in a
sump, prior to dismantling ad exploring further.
Sump full of water but no pump action. Moving the float about made no
differece. Tapping the pump casing made the pump work until the float
switch dropped to the cut off point.
Refilling the sump and again no pump action until tapping the casing and
again stopping properly. I cannot see what in the way of sticky motor
brush or loose/corroded contact inside the motor housing could produce
this symptom.

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.

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.

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.

Post by N_Cook
The other consideration is it was installed 10 years ago, tested working
then, but never heard to be working since.

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.

Post by N_Cook
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.

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.

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.

[GB]

Post by N_Cook
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.

What does the JT Pumps technical helpline suggest?