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Now without stating the obvious (ie replace the wiring loom) does anyone have any tips on repairing the cables on these as they are so thin.
Re: NTC cable repairs
the cable is only small because there is little or no current flowing. it does not matter if the cable you use to repair it is twice the size
Dave
Re: NTC cable repairs
electrofix wrote:It does not matter if the cable you use to repair it is twice the size
Really?
Re: NTC cable repairs
kladave wrote:Now without stating the obvious (ie replace the wiring loom) does anyone have any tips on repairing the cables on these as they are so thin.
Fisher &Paykel used to do some really thin butt connectors that you then put heat shrink over,John mac or Jonah may know a part no
Re: NTC cable repairs
Hi
When you see a BT or NTL van stop and offer some silver across his palm and ask for some silocone bomb (crimps). Their water proof and will cure most of the low voltage wire jointing problems 🙂
Bryan
Re: NTC cable repairs
I think Kladave may be referring more toward the later RAST type fitting NTC’s.
Re: NTC cable repairs
as a ntc has a pretty precise resistance, using thicker cable would give a false resistance thus sending the wrong signal to the pcb, i don’t use butt connectors at all in these instances joining the wires with a little solder and heat shrink usually does the trick, i have seen many machines with the wires simply twisted together and taped up which doesn’t appear to have ant adverse affect.
Re: NTC cable repairs
Didn’t liebherr or miele used to have a repair kit? Connectors,heat shrink etc
Phil
Re: NTC cable repairs
I can’t see why a thicker cable would cause any problems. Perhaps lee8 & martin could explain their concerns?
Re: NTC cable repairs
Hope I don’t offend or teach a granny how to suck eggs.
Because the pcb measures resistance (that’s why you measure the resistance of both ntc and ptc not just bell them out, hence why the cable size is so small, so there is less resistance) so altering the cable size does matter because it alters the resistance which in turn gives the pcb the wrong resistance reading so the temperature will not be correct.Ntc= negative thermo coefficient so the resistance reading should go down
Ptc= positive thermo coefficient so the reading goes upPhil
Re: NTC cable repairs
philfish wrote:hence why the cable size is so small, so there is less resistance) so altering the cable size does matter
No Phil, the thinner the wire the greater the resistance.
The issue here is patching up the broken wires and more and more NTC’s have thin ribbon cable with RAST type connector plugs. OK when the NTC has spade terminals as you can simply crimp on a couple of insulated spades. But not possible with the tiny pins used (see the photo I posted earlier) and I think that is Kladave’s problem..??
Re: NTC cable repairs
The thickness of the wire is certainly not an issue. With typical ntc resistance of 10-100 kOhm, and cable resistance well under 1 Ohm, the type of wire used will have no practical effect of temperature measurement.
The issue of connectors is broader than ntcs, and applies also to some inlet valves and many pcb edge connector. I guess these connectors are available, together with the correct assembly tools, if anyone knows of a supplier?
Re: NTC cable repairs
Martin wrote:I think Kladave may be referring more toward the later RAST type fitting NTC’s.
Sorry for the late reply but Martin is bang on,and suppose it’s just not NTC’s that have the connector either.
I will stop a BT guy next time,thanks Bryan.
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