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220V correct fuse value? and IGBT blow!

PostPosted: Fri May 04, 2018 11:40 am
by ElectroTom
I had a 4A 125V fuse in my 220v kit, I'm guessing it should be F10 250v as stated it the manual, and on the circuit board itself!?

The reason I ask is, that after fitting F10A 250V fuses, they blow, and the IGBTs measure as short circuits across all pins ! Would a 4A fuse save them!?? (IGBTs are £5 each in the UK and I have to wait..! lol)

Low power testing was fine.

After the power components were installed, checked for shorts ect, the device was plugged in, and I turned on the interrupter, selected fixed mode, the topload ejected a streamer for a millisecond and then 'pop'!

Suggestions please??

I saw in another post that there is a new shield component? (I was testing with all side panels off)

Thanks, Tom

Re: 220V correct fuse value? and IGBT blow!

PostPosted: Fri May 04, 2018 4:05 pm
by Bayley
Yes, the reason the coil ships with 4A fuses is to protect the IGBT's.
The side panels would probably fix the problems you are having, as would the shield (the new shields should be shipping soon, drop us an email and we'll get you one and some IGBT's when they are in stock).

Re: 220V correct fuse value? and IGBT blow!

PostPosted: Sat May 05, 2018 1:31 am
by ElectroTom
Oh ok, amendment to the manual then! By the way I also recieved the wrong resistor values for the interrupter. (The 100 ohm resistor was the only one I didnt have in my electronics box, pinched one off an old project). The voltage regulators were correct however.

..regarding the side panels/new shield panel design potentially causing this overload, what is the mechcanism of action taking place?
..RF inducing an alternating current in circuit(s) which heat/overload the igbts?

Regards, i'll email soon,
Tom

Re: 220V correct fuse value? and IGBT blow!

PostPosted: Sat May 05, 2018 9:50 am
by Bayley
The shield prevents the RF from latching the optical receiver on (which is what causes the single big spark) - I have no idea why some of the receivers seem to behave worse than the others (Industrial Fiberoptics has been quite unresponsive...) so we are just going to make the shield a standard part on the next batch of kits.