Relay for soft start

[robomatique]

I know this simple question might have been covered, but I just can't find a simple answer.

I am building a 5 channel UCD180 amp with total 100000uF and a 1000VA toroidal

Q1: What size of the relay should I go for in the soft start (when the soft start is bypassed by the relay, how much current does it have to be able to draw)?

Q2: What fuse size should I go for?


Thanks!
Robert

 

[fernando_g]

1000 VA/ 216V should give you 4.63 amp. I chose 216 volt because that would be 240V - 10%

But always keep a safety margin...go for a 10 amp relay.


For fuses, check the devices I2t curves, see a particular example:
http://www.littelfuse.com/data/en/Data_Sheets/312_318.pdf

 

[robomatique]

Thanks for great and quick answer!

That was all I wanted to know... until now...

If I have a DPDT relay being able to handle 5A, can I use both of the poles in parallell to get 10A (can a 5A DPDT relay handle 5A per pole)?

THanks again!

Robert

 

[paulb]

Generally no. Contacts don't share current very well. One opens or closes first. But you could try it if you have one. If you're buying, go for 10A.