Transformer Input Capacitance?

Hi there,

I have purchase some transformers to use with the 2Amps leading edge dimmer L5504D2A. Unfortunately there is no information written on the transformer regarding Transformer Input Capacitance. The details that i have is as follows:
EUROPOWER
Dimmable
MODEL:KT-60MS
20-60W/VA
Pri:220-240V-50-60Hz 0.25A
Sec:11.4V~eff,5A
Cos(phi)=0.98

I supposed that by dimmable means that can be use with leading edge dimmers but how can i found about capacitance? i did not find any information on the internet regarding this brand/model. Anybody also knows if the capacitor is in parallel with the 240V? i have open one unit and i did not see any capacitos in parallel with 240V but only one that is between 240V and 12V.
Waiting for the experts advice

 

Seems that nobody can advise me regarding this matter?

 

Transformer Input Capacitance

Went through similar angst. Not all transformer specs cover input capacitance. Have called manufacturers reps in the past and they're not even sure what input capacitance is. My advice; Don't go for the cheapest transformers ... you only get what you pay for. The Tridonic Atco Possum's are a good choice for C-Bus.

CIS used to test transformers for compatibility with their dimmers, but believe this no longer happens because there are far too many trannies in the market.

You'll need to push the manufacturer for details on this characteristic. It's not the responsibility of the dimmer manufacturer to test every transformer for suitability.

 

Hi Panther,

Thanks for your reply. Do you know if the capacitor is in parallel with the 240V input? I am asking so if is like that then we can measure it with capacitometer, otherwise we have to get the informations from the manufacturers which seems to be difficult.

Thanks

 

Transformer Input Capacitance

Again, that's a question you'd have to ask the transformer manufacturer. You'll save yourself a lot of time and effort by using the Tridonic ATCO Possum trannies. We settled on these as a standard pretty early on and they never gave us any problems. They may not be the cheapest on the market but they'll maintain the quality and value of a C-Bus installation. From memory, they had one of the lowest input capacitance ratings of all the trannies CIS tested. (And no, I don't work for Tridonic!)

 

Thanks again for your reply Panther.
Unfortunately i found that the specific brand can be found only on Australia. what about europe, is there any online shop that i can purchase trannies which have low capacitance? Also with Tritonic i may still have a problem as i have 8 halogen so i need 8 which Tritonic are rated on 33nF and i can use only 6.

 

Transformer Input Capacitance

Check out this post. It has a link to a couple of CIS documents that you may or may not have seen before.

http://www.cbusforums.com/forums/showthread.php?t=1888&highlight=transformers

 

Dear Panther i have seen those documents but are very old and since then there are a lot of other brands in the market that are not listed.
Nick this is a good idea but i don't now if by working 2x35W on 70VA transformer can haddle the load for a long time as the transformer will be in the maximum

 

A transformer rated at 70VA can handle 70VA for it's life time. 70VA is the maxium it can run at and it's fine to do so.

 

Yes Nick you are correct. Is better to use 105VA to be sure that will not exceed the capacity by any mistake. All depends what trannies i can find in local market.