Strand Tempus & RCDs 63A interlocked CEE forms required

[JSalisbury]

Hi all,

A venue I work with has two old strand tempus dimmers that could date back to the mid 1980's. The venue has been recently refurbished, but the management have reused the old dimmers. The building has been rewired up to the supply to the lighting desks and as such the electrician has put it all on one single 63A three phase supply 30ma RCD, one phase for each dimmer. How likely is it that I will see that RCD trip in practice? Where are good places to get some 63A cee form switched and interlocked sockets?

 

Thanks

[peterdevon]

I would get it changed to three separate rcds to stop it all going off at once. Most electrical wholesalers will keep the plugs the sockets will probably need to be ordered, when I recently needed some Demans were the cheapest with CEF quoting four time as much!!

[PaulDF]

Do you need the supply to the dimmers on a socket?

The installation I deal with, albeit 3 off betapack 1, were installed in the early 90s and are hardwired to the mains via a 3 phase isolator and 3 individual 30mA RCDs.

[JSalisbury]

Hi,

It is currently hard wired, it would be usefull if they were converted to sockets as the Tempus units are elderly and have failing channels. The thinking being if there was a major failure then something else could be brought in on hire whilst the dimmer packs were fixed.

 

Thanks

[ramdram]

We have 4 Beta2s in a cab with each of the dimmers connected via its own 63A plug and socket. The dimmers are across 2 phases and the third phase is used to supply the rings throughout the venue. Sound is powered off the third ring to avoid any shash from the dimmer circuits and has worked well thus far...years in fact.

 

The dimmers are "movable" owing to the place being in the open sort of and all the kit is taken "indoors" for the winter. Circuit protection is via four separate RCDs sitting on each dimmer circuit. (Obviously this allows for "a" dimmer to fail and only that circuit trips and therefore such an event is not a "showstopper".)

 

Perhaps you just need to reassess the circuit protection issue.

[mutley]

...it would be usefull if they were converted to sockets as the Tempus units are elderly and have failing channels.

 

Slightly off original topic but....

I have a few of these dimmers myself, and the polyester capacitors on the outlet board (about 50mm wide, positioned between front sockets), tend to spew their guts out. I strongly recommend you replace these with proper X and Y rated capacitors. I have seen the polyester ones sizzling and smoking from the cracks in their epoxy casing!

 

Any dead channels after that, are probably down to the triac/thyristor. Replace with any similar triac of equal or higher voltage and current rating.

 

Apart from these minor flaws, the Tempus dimmers are pretty indestructible! I've even added a Socapex socket to each of mine, and am currently working on an internal DMX demux board for them!