Understanding Ceramic Tube Fuse

[DCBUS]

Hello,
I am repairing a home receiver and the switch fuse has blown. This unit has a ceramic fuse that is rated 10AH. I see that the "H" is a High Breaking Capacity fuse. I find many on the market that are Quick Blow Ceramic Tube Fuse, but I am assuming this is incorrect to use and that it is important to use a "H" series. If this is true, can anyone point me in a direction to find this style of fuse.

Thank you,
JR

 

[tvtech]

In my experience ceramic fuses don't shatter the same way glass fuses do when faced with a massive overload. In your case replace with a normal glass fuse with the same size and rating and you should be OK .

If it blows again, you have a short on either your bridge rectifier or transformer.

 

[DCBUS]

Hello,
OK, thank you for the response.

 

[Nigel Goodwin]

In my experience ceramic fuses don't shatter the same way glass fuses do when faced with a massive overload.

I've always found the exact opposite - it's far more common for ceramic fuses to 'explode' - and far more common for them to blow for no reason. Back in the CRT days a number of TV models started fitting ceramic fuses, for no reason that was evident, or that they could explain, and they often blew for no reason (we always replaced them with standard glass A/S fuses, never failed again).

We only ever kept two ranges of fuses - glass A/s (T) ones, and specific microwave oven fuses (ceramic).

You do occasionally see glass fuses where just the ends are left, but we used to see far more ceramic fuses like that, despite the number of ceramic fuses been vastly smaller.

Certainly the fuse manufacturers claim that ceramic are more robust, but I've never found it so.

 

[DCBUS]

Hello,
So if the current fuse is a ceramic 10AH 250V I can replace with just a glass version 10A 250V.

Thank you

 

[Nigel Goodwin]

Hello,
So if the current fuse is a ceramic 10AH 250V I can replace with just a glass version 10A 250V.

Thank you

I would do so, do you have 110V mains?, as it seems quite a high rated fuse.

The highest fuse we used to keep (other than microwave oven fuses) was 3.15A A/S.

 

[DCBUS]

I am not sure of the mains, but that was the fuse removed and also marked on the board at the fuse holders. Thank you

 

[Ylli]

Ceramic fuses tend to be slow-blow. Sometimes they are even filled with sand to help dissipate normal heating, but to still allow the fuse to 'blow' with a high current overload. I'd suggest a 10A 250V SB fuse.

 

[rjenkinsgb]

Sometimes they are even filled with sand

The sand is what gives them the "HRC" (high rupture current) rating - it prevents or at least reduces the chance of a plasma arc forming if the fuse element vaporises as the fuse ruptures.

To my experience, all HRC types are ceramic - but I only buy branded ones. It may well be there are cheap ceramic bodied ones that are not actually HRC rated; that could explain Nigel's experience with them.

You can get the three common speed ratings - T, F & FF - in ceramic types.

 

[tvtech]

I've always found the exact opposite - it's far more common for ceramic fuses to 'explode' - and far more common for them to blow for no reason. Back in the CRT days a number of TV models started fitting ceramic fuses, for no reason that was evident, or that they could explain, and they often blew for no reason (we always replaced them with standard glass A/S fuses, never failed again).

We only ever kept two ranges of fuses - glass A/s (T) ones, and specific microwave oven fuses (ceramic).

You do occasionally see glass fuses where just the ends are left, but we used to see far more ceramic fuses like that, despite the number of ceramic fuses been vastly smaller.

Certainly the fuse manufacturers claim that ceramic are more robust, but I've never found it so.

Once again, Nigel refutes anything I type technically wise. He always thinks he knows better than me. So be it.

That's all I have to say.

This is my last post on anything Technical here.

 

[Nigel Goodwin]

Once again, Nigel refutes anything I type technically wise.

You've had one experience with ceramic fuses, I've had another - I don't see your problem?.

Do you still find TV's with ceramic fuses in them?, they were quite rare over here.

 

[tvtech]

All LG 54cm CRT sets have them. Even with lighting strikes on PSU they don't explode. Just go open and do their job as best as possible.

No drama.