Chair lift fault.

[ericmark]

My mother rarely goes upstairs and when she does it's with me so the stair lift sits unused for months on end.

In the past we had a problem where it was not parked at charging station and winding it back to charging station failed to charge the battery and they had to be renewed before it would work again.

Yesterday I decided to test the chair lift and it went around 1 foot before it failed I will assume a battery fault and I had to wind it manually back to the charging station. OK no real problem mother was not sitting on it.

It is Simular to this one an older Stannah and I will clearly need to re-test once it's had a chance to re-charge but it rather worries me as it did not display any warnings of battery becoming discharged it simply stopped. Had my mother been on the stair lift it would have been a fire and rescue job to get her down again. She can't walk at all she only has one leg and over 90.

It seems rather strange that there was no warning of batteries going flat. And I wonder if there is some other fault other than a flat battery as it seems odd there was not buzzer light or alarm to warn batteries were going flat.

For those who have not seen a stair lift it has two sets of rechargeable batteries and two PP3 batteries. The 24 volt rechargeable batteries bring an arm down to complete the track at bottom of stairs with an RF link to either of two control stations one top and one bottom of stairs. Once down then you have the option of using three control stations one top one bottom (RF link) and one on the chair to run the chair its self. The rails have three charging points one top one on bend and one at bottom although the latter is useless as the arm has to be down to use and that blocks hall way. Once away from charging station it used again 24 volt rechargeable lead acid batteries similar to those found in alarm panels.

So the electric supply is only for the chargers the chair always runs on batteries.

I have a feeling although installed for the county council it was installed by cowboys as one can't see the bottom leg from stop of stairs and your only indication as to if fully home is the noise from motors you hear them strain once home. There is no E-Stop or any sensors to stop the leg from crushing anything in it's way. The chair will not move until leg is down so from top you do know leg is down but nothing to show you leg is up so my father had when he used it a few times stopped my mother leaving the house or accessing the chair controls as leg was not fully up.

If on return the fault still exists my first move will be to swap leg and chair batteries around but I have serious concerns about the safety of the chair which gives no warning it is about to stop working due to flat battery.

When my dad was using it I was not so worried he could walk if it failed and he used some common sense.

So has anyone worked on these chairs? If so is it normal not to have any safety switches on the bottom arm and is it normal not to have a warning about batteries becoming discharged before the motor stops?

 

[bernardgreen]

I am surprised that the chair lift relies on batteries.

Given the type of service that a chair lift has provide I am surprised they have moved to battery operation. It may simplify the design and installation of the system but at what costs.

Both the stair lifts my mother had were powered by a 24 volt supply cabled to the chair. The cable also carried the control circuits to and from the chair.

The first chair lift was a simple straight one with ribbon type cable on a spring return drum under the chair that unwound and rested on a flat section of the track. The cable was terminated at the bottom end of the track where the PSU and control.

The second was on a flight of stairs with a 180 turn. This used a round cable on a drum under the chair. This cable unwound into a channel on the outer side of the track. To reduce the amount of cable on the drum the cable left the track at the mid point.

This was very reliable other than a problem with the cable retainer at the mid point. Battery back up was an option but only to move the chair to a place where the rider could safely dismount. Mum didn't think that was necessary as she could manage the stairs but only slowly.