TQ1 belt and capacitor

[Martin Davey]

Dear Forum,
I'm currently replacing the belts on a B&H TQ1. However one belt, the toothed long 'timing' one, I have not been able to install. This is because it needs to go over and under a very large capacitor, and as I have no electrical knowledge I'm worried about this element. Normally I leave capacitors well alone but here I have to either remove the 4 screws holding it in place or remove the three wires connecting. As I understand these things hold a powerful charge so natually I don't want to 'have a go!'
I would appreciate any advice, thanks.

[Steve Klare]

Hi Martin,

Capacitors aren't like batteries: generally they don't store energy very well over the very long term. (-especially old ones...)

Here's something you can do: Leave the machine unplugged for overnight or a day or a weekend, -whatever is convenient, just not something like 10 seconds, give it hours.

When you are ready to work, put on some kind of work gloves. Connect the unplugged terminals of the line cord together with wire and operate the motor switch in every position. Then expose the three capacitor terminals. Take a length of wire and short each terminal to the other two (bonus for all three at the same time: clip leads?): this should discharge any residual energy. If you get a spark, you know there was some remaining. If you want to get fancy about it, you can use something like an incandescent light bulb in the discharge circuit so you don't even get a spark.

[Martin Davey]

Thanks Steve for the reply.
Since my post I've notice that there is a yellow wire bonded and imovable between the motor and capacitor, so uncliping those 3 wires would not make any difference. This would mean to get the drive belt around I would have to physically handle it by taking out the four screws!

[Maurice Leakey]

Martin
May I respectfully suggest that in view of your problems with screws and possibly, their nuts, that you have a word with Kevin Brown.
KB Cine Repairs, Nottingham | Home Cinema - Yell

[Nick Regan]

If you undo the two screws to the RHS of your picture the Bracket there that holds the cap should allow the cap to swing down (or come out still attatched) to the cable so you dont actually touch anything that might bite.

If I remember correctly the same sort of thing happens with the LHS assembly allowing the belt to be fitted with minimum disruption.

Nick

[Maurice Leakey]

Nick
I believe that care must be taken as the two screws that hold the capacitor bracket have securing nuts below that might just fall down inside.

[Nick Regan]

Nick
I believe that care must be taken as the two screws that hold the capacitor bracket have securing nuts below that might just fall down inside.

Sorry Maurice I should have mentioned that although some of the models the top part of the cap bracket has a U shaped hole in it so if you just loosen the screw the bracket top should be able to be pulled towards you with the screw remaining affixed to the chassis.

[Martin Davey]

Thanks Maurice and Nick,
There are no nuts on the screws. However looking at the belt itself I've decided to keep it in for a few more years as it seems in good shape, unlike the others. When it comes to changing this belt in the future I will allow a month for it to discharge and set the controls/ amp in the on position during its storage before removing. I presume the cyclindrical part is never exposed 'live' and only the 3 metal contacts when exposed are the parts to avoid, not that I would have to remove them anyway?