Thermal Circuit Breaker Problem - can we fix it?

[dicky96]

Hi guys
I have this ETA 3120-F321-P7T1-R14XB3 Circuit breaker from a Hill DX3000 Power Amplifier.

The first problem I found with the amp was a faulty 25A Bridge rectifier FB2506 that was short circuit on one leg AC to negative

I've replaced that but the amp has no power. That is because the ETA circuit breaker is open circuit on one pole. The other pole switches OK. The primary of the transformer seems OK (not short or open and doesn't look distressed) so I think that ETA circuit breaker is the only other problem I need to fix.


Problem is finding a replacement. I can find some similar that have 3120-F321-P7T1-xxxxxx but the last digits are different.

The similar ones I can find are silly expensive like 40 quid or more and mostly in the USA.

What is inside these circuit breakers? I have had success in the past dismantling multipole switches and fixing them (usually heavily coroded contacts)

If the circuit breaker is actually a double pole breaker and one pole is working, could i just short out the o/c side?

Add an inline fuse for safety instead?

Looking for a replacement, an equivalent part that isnt silly money, or how to dismantle and fix this one



best regards
Rich

[R_J]

Re: Thermal Circuit Breaker Problem - can we fix it?

Here is the pdf for the E-T-A 3120 series
They do have a "switch only" without the breaker that would fit, and you could add a seperate circuit breaker in ine

[sam_sam_sam]

Re: Thermal Circuit Breaker Problem - can we fix it?

That part number might made for just that company that made that amp
So you might not be able to get the exact part

[dicky96]

Re: Thermal Circuit Breaker Problem - can we fix it?

Thanks for the advice

One pole of the circuit breaker switches fine, so I think i will refit it and just another circuit breaker where the leads go to the faulty (open circuit) pole and it should work fine

Something like this one https://www.ebay.co.uk/itm/Techna-T1...EAAOSwszZa5-hL I can get for less than £5



Rich

[sam_sam_sam]

Re: Thermal Circuit Breaker Problem - can we fix it?

Thanks for the advice

One pole of the circuit breaker switches fine, so I think i will refit it and just another circuit breaker where the leads go to the faulty (open circuit) pole and it should work fine

Something like this one https://www.ebay.co.uk/itm/Techna-T1...EAAOSwszZa5-hL I can get for less than £5

Rich

I would recommend replacing it with two separate breaker because I would not be surprised if the other half might be damaged in some way