Stairlift problems ... thinking caps on

[adctd2shindig]

Please can someone help. My customer has a battery operated stairlift, powered by a 12v transformer. When plugged into any socket, the charger stops charging after 2/3 hours. If the plug is placed 10 meter ext. lead, in same socket, the charger continues to charge. There is no voltage drop when using the ext. lead, I cannot work out what the problem is.

 

[Darkwood]

i would be inclined to think the charger is reset when de-energised and the control circuit will initiate charge when power is re-applied regardless of battery charge until the monitoring circuit establishes whether the battery is full or the require topping up. I cant see any reason electrically for it to do what you are saying.

 

[adctd2shindig]

Hi Darkwood, thanks for your reply, I also cannot see an electrical reason for it. The radial final circuit also serves the 24 callout alarm service and a pc, both of which don't have any power problems. The transformer has been checked out by the stairlift maintenance guy, and is perfectly ok. It is just weird how it will keep charging directly via the extension lead, which she would like to get rid of as it is dangerous where it is, and will not charge directly from the wall socket after anywhere between two or three hours. Should I try an FCU, with a 3 amp fuse?

 

[Darkwood]

Change socket front and plug, cheap to do to narrow issues down with.

 

[Rockingit]

^^^ what he said!

 

[imago]

Could it be a heat issue? Is the socket right next to a radiator for example?

 

[nickblake]

What about the battery is that ok if the cells are dead it may well stop charging , always wanted to change the speed of staire lift just like they did in gremlins hehe sorry sense of humor and all that

 

[adctd2shindig]

Hi, I have already changed the front of the socket and rear, I changed it from a single to a double so it could also power the telephone without the use of a double adapter.
It is not near a radiator either, nor other heat source, the socket is only three meters away from the consumer board. There is no power or voltage drop. I have wracked my brain as to what could be the problem ....

 

[adctd2shindig]

Hi, it was serviced by the chairlift engineers, I would have thought they would have checked the battery then. Also, it fully charges via the extension lead, but not the plug :/

 

[Darkwood]

My final thought then is the charging unit, it will be converting the power ac to dc and chopping the wave form up, i assume it will dump the created noise to earth but if theirs any reason it cant then it may prematurely shut off, the longer extension may act as a capacitive device helping the noise disipate but this would all point to an earthing issue with the socket, have you carried out an Earth loop impedence test on the socket?
At the end of the day all you require to do is prove the socket is fully functional and the stair lift will lay with the responsibility of the company who supplied it or rents it... if it still isnt charging they should be called back in until they resolve the problem with their stair lift.

 

[adctd2shindig]

My final thought then is the charging unit, it will be converting the power ac to dc and chopping the wave form up, i assume it will dump the created noise to earth but if theirs any reason it cant then it may prematurely shut off, the longer extension may act as a capacitive device helping the noise disipate but this would all point to an earthing issue with the socket, have you carried out an Earth loop impedence test on the socket?
At the end of the day all you require to do is prove the socket is fully functional and the stair lift will lay with the responsibility of the company who supplied it or rents it... if it still isnt charging they should be called back in until they resolve the problem with their stair lift.

Many thanks for this and all your input. I can see where you are coming from with this reply. I will test the earth impedence tomorrow when I am there, the stairlift co., has told her it's down to her electrics.
If nothing else works I will put in a new final circuit from the board to an FCU as there are plenty of spare slots.

 

[UNG]

Hi, it was serviced by the chairlift engineers, I would have thought they would have checked the battery then. Also, it fully charges via the extension lead, but not the plug :/

You are making an assumption there and without checking it yourself don't assume they have. How do you know it fully charges using the extension lead or are you relying on the charger indicators which may be giving false indication due to a battery problem

I assume this chairlift uses sealed lead acid battery which have a finite life if they have been in use for a number of years they may well be reaching replacement time I would test it using an ACT battery tester or similar this will give a good indication of the battery serviceability

 

[adctd2shindig]

How do you know it fully charges using the extension lead or are you relying on the charger indicators which may be giving false indication due to a battery problem


Hi, thanks for the input, I should have said that when plugged directly into socket it indicates charging, but then after about 2 hours an alarm starts to say it has stopped charging. This does not happen via the extension lead. When using the lead, it charges for hours until fully charged with no alarm set off or the charging interrupted at any stage. That's why I have not checked the battery. The chair works perfectly when it is charged via the lead.

 

[UNG]

If you carry on assuming it is working correctly via a lead and are not prepared or may be not equipped to carry out proper testing then I'm out

 

[dean.diy]

evening adct. Did you change the plug on end of chair lead?
I see the s/o got changed.

 

[adctd2shindig]

If you carry on assuming it is working correctly via a lead and are not prepared or may be not equipped to carry out proper testing then I'm out

I am perfectly prepared and equipped to carry out proper testing, and have tested everything except the earth impedence, which I am carrying out tomorrow. I am NOT assuming it is working correctly via a lead, it does the same on the ring socket as well, going off after 'x' amount of time, that is the reason I am on here asking if anyone else has come across such a thing. Two heads are better than one, so they say.
I have tried 99% of the things I can think of to work out why it is only working correctly on the lead and have not come to a conclusion. I am certainly not a 'cowboy Electrician' if that is the implication, if that were the truth, I would not care either way, and would leave it working on the lead.

 

[Darkwood]

Just here to clarify that you have said you have already changed the socket to a twin... you will have already done an ELI test to confirm the correct safety of the socket... but reading further it dosen't seem to be the case, although disregarding this i dont think this is the issue but im inclined to think the product is at fault... submit a cert' for the circuit that it is within reg's and let the chairlift company worry about the charging issues.... if you dont youll be going around in circles trying to find a fault that isnt on the installation side.

 

[1shortcircuit]

submit a cert' for the circuit that it is within reg's and let the chairlift company worry about the charging issues.... if you dont youll be going around in circles trying to find a fault that isnt on the installation side.

I agree, if you have done all of your tests and results are satisfactory then it is the stair-lift company/manufacturers problem.

 

[Rockingit]

Just a thought..... and this is a big think...... what IF there was a polarity cross-over on the manufacturers side (which might explain the symptoms??) AND purely by chance the lead you've got also happens to be cross wired.... so in other words it inadvertantly corrects the problem.

BTW, this suggestion is incredibly far fetched, but truth is stranger than fiction sometimes.

 

[Darkwood]

Just a thought..... and this is a big think...... what IF there was a polarity cross-over on the manufacturers side (which might explain the symptoms??) AND purely by chance the lead you've got also happens to be cross wired.... so in other words it inadvertantly corrects the problem.

BTW, this suggestion is incredibly far fetched, but truth is stranger than fiction sometimes.

See you angle here but from the OP explanation it charges for a few hours, if the charging circuit was polarity conscious it wouldn't charge and its also a rectified ac to dc signal so it wouldn't be a problem as irrespective of ac input the dc would be correct due to the diodes in the full wave rectifyer. I feel we either lack the full info or the battery/charging system are at fault.