Ballast overheating

Hello I am in the last weeks of Wurlitzer 1900 restoration and need to ask about fluorescent ballast. The original ballast metal case was missing from machine so I screwed ballast modules directly onto inside of cabinet. After an hour or so they were hot ,hot ,hot. Do these need good heat dissipation or are just old and need modern replacement. I hope this is not a stupid question. Thank you . Mark from Australia.

Hi Mark,
Originally, the ballasts on the V ( and other) models were "supported" on rubber grommets, to keep the heat off the wood. Over the years, these "disappear", and people tighten the screws down so the ballast is tight against the wood. I have no idea as to if your ballast is "overheating" or not---but I would suggest that you at least, find new mounting grommets, before it catches the wood on fire--which I have seen, too many times !
I usually insert a chunk of flat metal between the ballasts, and the wood, and---If you really want to get "fancy", space that metal away from the wall and mount the ballast to the metal--
Also--especially on the V models--SOME of the TSR's are not fused, for the lamps--I add a three amp fuse in series with the lamp cord-- Ron Rich

I have seen jukes where the factory put asbestos sheets between the ballast and the wood to prevent a fire.

Some ballasts do run hot. However, if it's getting hot (or overly hot) and leaking/oozing, then it's time to replace it.

Hi Ken,
"Asbestos" was used in later models, along with the grommets--however, it was stopped sometime in the 60's, when we had all of the "asbestos fears". Ron Rich

If the ballasts were designed to run on a 60hz supply, and they're running on a 50h supply they may run hotter than intended, this is unavoidable.

My 1970 Rockola 442 had asbestos backers, but not sure if they were factory fitted as someone had changed all the ballasts for UK ones...I've now put the correct USA voltage ballasts and tubes back in and disposed of the asbestos. I've found a really good replacement material to be a plumbers solder mat, available from a DIY store for not much money and is easily cut to size to perform the same function. It's some form of cloth matierial, is asbestos free and can tolerate up to 1000 degrees C! So far it's worked great for me and no problems. My ballasts do get pretty hot, but then so did the UK ones that were fitted when I bought it. No cabinet burn so far

All good now. Ron, I rubber mounted ballast as advised and put them on metal `stand off`s ` Hot still but not fingerprint removing hot. Machine is operating through a 240 volt ( Oz voltage) to 110 step down converter. with 20 watt lamps. Thanks to all as this could easily have become a fire hazard. I had no idea they generated that much heat. Will post pics of finished machine soon. All the best ,Mark.

Glad to hear you sorted it. I see mains voltage in Oz is also 50hz so they will run slightly hotter than machines owned by our American cousins

Psychman wrote:Glad to hear you sorted it. I see mains voltage in Oz is also 50hz so they will run slightly hotter than machines owned by our American cousins

Thank you Yes sorted The 50 hz thing is not a big problem generally except for the nightmare Seeburg`s rpm gearing change. Again thanks to all for preventing a possible fire. These ballast were white hot before mods . All the best