Electrical problem with Grundfos macerator

[jazzguitar]

I have a grundfos sololift 2 wc1 macerator that isn't working. It's about 3 years old. When the toilet flushes the bowl just fills up but the motor does not kick in. There is power going to the unit, The macerator motor/pump turns freely. I took the motor apart in the hope that there may be debris, but nothing preventative(Just hair wrapped around the spindle). The small trip switches are in the correct position. There is power coming from the large capacitor and from what i assume is the pressure switch

Any advice on getting it working would be most welcome.

Thank you

 

[Timbo]

Put that silly voltstick away and use a meter to check for 230v across L-N.

 

[brianmoooore]

It looks like you are expecting too much from a non contact voltage indicator. These things have their (limited) uses, but aren't really suitable for close in voltage detection.
Having said that, it looks like you are detecting 'power' everywhere, including where there shouldn't be any, so the first thing I'd do is check the supply neutral is present.

 

[jazzguitar]

Here is it with meter readings. 230v all around except for what i think is the pressure sensor which is reading about 16. 230 from the big cap too.
Any help would be really appreciated
thanks in advance

 

[brianmoooore]

Video jerks around too much to be sure, but I think you have confirmed what I suspected - there is no neutral supply.

 

[jazzguitar]

Video jerks around too much to be sure, but I think you have confirmed what I suspected - there is no neutral supply.

I can do another one. By no neutral supply, ie the blue wire, what should it be reading and is there anything I can to to fix it?

 

[jazzguitar]

Is this more helpful? Although I have some electrical experience it was a long time ago.

 

[brianmoooore]

There should be no significant voltage between the neutral (blue) supply wire and the earth (green/yellow) wire.
There are four terminals on that connector block, and parallax makes it difficult to see which wire you are testing, but it very much looks like you have full mains voltage between earth and neutral.
Could also mean that the earth is sitting at full mains, but I doubt it, since you have not electrocuted yourself.

 

[jazzguitar]

the four block are two ins and two outs(live-brown, neutral-blue and two outs- both.black). If I have full mains voltage between earth and neutral, where it shouldn't be, what would you reckon is the cause of this and how would one go about fixing it?

again, Thanks in Advance

 

[brianmoooore]

First place I'd look is at the other end of the supply lead. Turn off the power at the fusebox before removing the faceplate of any fitting.
Was the wiring for this unit done by the plumber who fitted it?

 

[jazzguitar]

yes it was.. I have checked behind the face plate all seems in order. i also stuck a continuity tester between the live and neutral(with the power off) but there is no short.

Here is a schematic if it helps

 

[Lucien Nunes]

One would not expect to find a short or the fuse would have blown, but a continuity tester will read continuity across the motor winding if there is a circuit through the unit.

If I have full mains voltage between earth and neutral, where it shouldn't be, what would you reckon is the cause of this

Assuming that the earth is connected and intact, and that the unit is energised with the float switch closed and supposed to be running, then any part of the neutral wire that reads more than a few volts to earth is 'floating' i.e. not connected to the supply neutral. The break is between that section and the supply.

 

[brianmoooore]

Need a pic of the inside of what is at the other end of the supply lead.
It's very likely there's nothing wrong with the macerator at all.

 

[jazzguitar]

One would not expect to find a short or the fuse would have blown, but a continuity tester will read continuity across the motor winding if there is a circuit through the unit.




Assuming that the earth is connected and intact, and that the unit is energised with the float switch closed and supposed to be running, then any part of the neutral wire that reads more than a few volts to earth is 'floating' i.e. not connected to the supply neutral. The break is between that section and the supply.

I checked for continuity by removing the two wires from the cap that go to the motor. I am getting continuity there

 

[jazzguitar]

Need a pic of the inside of what is at the other end of the supply lead.
It's very likely there's nothing wrong with the macerator at a

seems to be three sets of twin and earth wires(Brown blue and green) Going into the switch and then a fourth flex leading to the macerator.

 

[brianmoooore]

That does not look good at all! Far too busy in there, and putting a lot of strain on the FCU.
Can't see any sign of a flexible there? The connection to Nout looks like another solid cored cable.

 

[jazzguitar]

That does not look good at all! Far too busy in there, and putting a lot of strain on the FCU.
Can't see any sign of a flexible there? The connection to Nout looks like another solid cored cable.

what would you suggest i do? There are no flexibles. all ins and out are the same. Grey insulation stiff wires. 4 sets in total. 3 in and one out.

 

[brianmoooore]

It appears to be a flexible at the macerator.

 

[jazzguitar]

It appears to be a flexible at the macerator.

yes. There is this at the other side of the toilet. Cant get a better picture that that. the solid core wiring is behind tiling.

 

[Lucien Nunes]

With the power off and fused connection unit switch off, test continuity from L, N and E at the load side of the FCU to the corresponding terminals in the macerator. It seems likely the neutral is broken at the dodgy taped-over terminal block connection in the last pic. That should not be there, suggests the cable was too short and they didn't have the right materials to extend it. Looks like 'plumber's wiring.'