That's a very good point BS3036. I should have read what it said in the description beyond where is says it can be used for low voltage lights. It has to be a wire wound transformer and I cannot immediately see a suitable transformer to use as the first 2 of these might work but not be...
You could add one of these before an in-line transformer: http://www.tlc-direct.co.uk/Main_Index/Lighting_Menu_Index/Wiring_Accessories~Dimmers_All/Wiring_Accessories~Dimmers_3/index.html
or call Mr Resistor www.mr-resistor.co.uk and ask about the combined transformer/dimmer that they told me...
Customer settled for a transformer without an upfront in-line dimmer. I used an aurora AU-E105 which comes without fly leads but with internal connections for mains in and 12v out. Cost £13.62
http://www.connectstores.com/P.E.D/sp_17781-20.html
but probably cheaper from wholesalers
MEM do a better item specifically designed for the job and used by some DNOs. I cannot find the exact reference number but it starts MEBAN2EBD
Chris
"ricicle": Are you sure the MFT1553 only needs 2 leads for no-trip loop tests? I've not seen it advertised as having that advantage over the MFT1552.
Chris
Thanks "hairyben" and "taylortwocities" but the dimmer needs to incorporate a 230 to 12v transformer if it is to directly and simply replace the faulty item. A less elegant solution would be an appropriate dimmer followed by an enclosed transformer in the lamp cable.
Chris
I've got exactly the same JN3060F on an expensive John Lewis floor standing lamp which has 5x 12v 10w bulbs. Cannot find anyone who does a single cheap identical replacement. Mr Resistor do something made in Italy (apparently) for about £30 delivered but my customer only wants to go up to £20...