Factors Impacting Daily Electricity Consumption of a 400W Pump: Overload, Short Circuit?

Hello,
I don't know if it's the right section, but I don't have any other ideas.

The question concerns exactly such a pump: http://www.toya24.pl/media/popup.php?store=4&id=6049
specifically, it is about the maximum possible electricity consumption per day by such a pump. Of course, I calculated according to the data from the description, i.e. for 400W 0.4kWh * 24 = 9.6kWk / day, but I mean are there any factors (short circuit, overload or anything else) that could cause this consumption to be higher? (if, for example, it could be greater under overload, then for how long).
Why am I asking this? In a house where I have tenants, I have such a pump connected through a sub-meter to the socket of one of the tenants. Yesterday she called me screaming that her electricity bill is higher by PLN 500 (2 month cycle), that an electrician came and said that I connected the pump wrong, etc.
I can't go there at the moment, but I would like to have some knowledge when I go there.
Are there any ways to check if it is actually this pump (previously, it used less than 2 kWh in 2 months)
Thanks for the replies.

There's definitely an induction motor out there, and these work like this: at rated load, they draw rated current. At idle, less and when the rotors stop, it is normally a short circuit!
Conclusion: power consumption strongly depends on the load, as the water flows through it, it is loaded, if it has to lift higher, it is loaded more. If there is a hydrophore tank, the current consumption will depend on the pressure maintained in this tank. As its bearings wear out or move, it will also affect wear (once someone from besel told me that they have a department where if the engine takes too much at idle, you hit it with a rubber hammer, the bearings set and it's still ok)

1) Measure with a clamp meter the current it consumes when it works
2) check that it does not overexert itself due to the pressure it works under. Filter clogged etc.
3) Check if it does not turn on/off too often because the starting current is always several times higher than the rated one (there is a short-circuit for a moment, logical), if there is a hydrophore tank with or without a diaphragm and the air has gone out of the diaphragm, or if there is no diaphragm and it has so-so (I pump mine every 2-3 months) the pump will be turned on/off by the pressure switch every moment. There must be an air supply.

roszej wrote:

(previously, it used less than 2 kWh in 2 months)

I understand that the pump worked cyclically? The float could be jammed, the pump works all the time, which gives 585.6 kWh at rated power for 61 days, and the rest as michcior says

This pump was designed to maintain a constant (lower than normal) level in the septic tank with dirty water (so-called thick water was collected in the first tank, and there is water in the second one) and the pump was only supposed to pump a certain amount of water (about 2m3) to the next well ) because the level difference was too small.
There is a float switch in it, but somehow I do not want to believe that it failed, the pump is about 5 months old.
So if the impeller jammed, would the protection pop up?

roszej wrote:

So if the impeller jammed, would the protection pop up?

Right away. It's a short circuit.
But when it gets clogged and it only spins, it's hard for it to take more current.
I don't really understand what the electrician meant when he said "wrongly connected". Electrically, probably not, because he would say, and hydraulically, what does he say when he is an electrician? He said what he knew "badly connected" but what was wrong he didn't say. It's not worth talking.

Or maybe the tenant used more water and thus the pump had more to pump...

michcior wrote:

roszej wrote:

So if the impeller jammed, would the protection pop up?

Right away. It's a short circuit.
But when it gets clogged and it only spins, it's hard for it to take more current.
I don't really understand what the electrician meant when he said "wrongly connected". Electrically, probably not, because he would say, and hydraulically, what does he say when he is an electrician? He said what he knew "badly connected" but what was wrong he didn't say. It's not worth talking.

Well, he allegedly meant that I probably connected this meter wrong, and I connected it correctly, it normally counted and the previous electricity bill did not arouse suspicion, and that the pump turned on every two or more days for a maximum of several minutes (up to 30, let's say) because the consumption water in the building is in the range of 15-19m3/month, I believe that the consumption was approx.
And hydraulically, it was not a philosophy, because the pump pumped water into a pipe that was about 50 cm higher than the pump itself (a fi40 PE pipe was connected to the pump)

And as for the consumption of more water by the tenant, it is rather impossible, the water consumption in the building never exceeded 22m3, so even if this pump was to pump these 22m3 and turned off, it would consume a negligible amount of electricity.

It wouldn't be a problem if I had my meter there, but there are no more free cables, there are just as many cables as apartments.

Hello.
1) Ask an electrician personally what it means (.... wrong connection ....).
How is the pump power cord protected against moisture, is it in one section? Is it not damaged?

2) Second possibility; wrong meter readings.

What is the purpose of the room with the power socket for the pump; this socket can be powered from a new submeter and counted from the indications of the tenant.

It seems to me that until we find out what the meter shows, we will only guess. As I understand it, the tenant complains that she paid a lot for electricity, but it is not known how much the sub-meter shows.

1) Check whether the sub-counter indication corresponds to this increased consumption - if so, we have a technical problem with the pump / installation.
2) What if the sub-counter showed too little? I wouldn't trust this lady more than a meter. Maybe she pulled through the winter on farelki and now she wants to blame it on someone, people are unpredictable.
3) There is also a third possibility that a third party steals its electricity, I don't know how the wiring is there, could someone get to this installation and the sub-meter. Here, too, human fantasy knows no limits.

Thanks for all the replies. Today I got there and what turned out that the connection was good. The meter showed only a few kilowatts from the previous state, but the consumption was due to the pump. The pump does not work (burned out?), the meter does not spin and the current is leaking. The meter does not spin because the tenant plugged the plug into the socket in reverse and in the place where the neutral wires are on the meter, a bridge for the phase was made, of course nobody knows anything, nobody touched anything, but I don't want to challenge them there anymore. I made a seal on the meter itself, but I didn't think - to allow the pump to be disconnected in case of emergency - that someone could put it backwards.
I have a lesson, my question is only mine - due to the fact that it is a TN-C system with PEN - how to connect it all to protect against such a situation? I thought about a permanent connection to the box, with a residual current, electronic meter and an ESEM also acting as a switch in case.

roszej wrote:

Thanks for all the replies. Today I got there and what turned out that the connection was good. The meter showed only a few kilowatts from the previous state, but the consumption was due to the pump. The pump does not work (burned out?), the meter does not spin and the current is leaking. The meter does not spin because the tenant plugged the plug into the socket in reverse and a phase bridge was made in the place where the neutral wires are on the meter, of course no one knows anything, no one has touched anything, but I don't want to challenge them there anymore. I made a seal on the meter itself, but I didn't think - to allow the pump to be disconnected in case of emergency - that someone could put it backwards.
I have a lesson, my question is only mine - due to the fact that it is a TN-C system with PEN - how to connect it all to protect against such a situation? I thought about a permanent connection to the box, with a residual current, electronic meter and an ESS that also acts as a switch in case.

Hello. After reading this post, he has this advice; have an electrician do it. It will do what you want, and it will also be safe for tenants.
At least we know what the electrician meant when he wrote "bad connection"

energy consumption in the pump results from the resistance of the installation and the required height of pumping the fluid and the difference in height between the fluid mirrors. And not from the engine's electrical power alone
I recommend the website www.wilo.pl there you will find everything you need along with diagrams of electrical connections, control and protection of the pump and electrical installation.

Added after 2 [minutes]:

And one more thing 0.4kW*24h=...kWh approximately if it worked at full load for 24h.