Thorn 200W SLI?H HO Linear Sodium Lamp

[bobhowe]

Hi my other interest is street lighting and in my lamp collection I have a Thorn 200W  SLI/H HO linear sodium lamp . This been a HO lamp it will not work with a conventional ballast glow start circuit at has to have an instant start BLI Autotransformer with a 30MFD 450V capacitor to work with this lamp and they were made in the 1960s and are now impossible to obtain now .A few lighting collectors have these Autotransformers but they are reluctant in parting with them . This lamp requires an IGN voltage of 320V and the running voltage is 145V at 1.6A . It had been suggested on various forums to use a 180W sun bed ballast as it provides 1.5A .Managed to power it up with a sun bed ballast with a SOX ignitor but the currant draw exceeded 2A .Next step is to get a 175W CWA Metal Halide Autotransformer that does power this lamp with no issues  but these are like hens teeth in the UK & EU but readily available from the US but they run at 60HZ . You can get a multi tap version and if I change the starting capacitor from 10MFD to 12MFD and use the 277V tap it should work without the Autotransformer overheating .  ( Hopefully ) I have ordered 2 from the US for £55 including shipping and import charges kind regards Bob

[Diabolical Artificer]

We use to use old street lights for growing "tomatoes" back in the day pulled from scrap yards, a good source for bits and bobs. Unfortunately Leicester Constabulary nicked my lights otherwise I could have helped. I might have an auto tfmr off a washing machine though, will look.

Andy.