Trace Elliot Boxer 15 fuse

[bode]

The original 'kettle' lead for my little Boxer 15 amp has gone missing after the other half decided that she didn't want all my music stuff cluttering up the living room. 😁 

What fuse should I be using in the plug, 3A or 13A?

Thanks! 

Edited June 11, 2021 by bode

[BassmanPaul]

The amp itself will have a suitably sized fuse to protect it. I can't remember what fuse values are available in the UK. You can try the 3A and if it fails the 13A will be fine.

[Downunderwonder]

I'd be surprised if you could  blow a 3A fuse but I am unfamiliar with UK codes.

As I remember you guys don't have fuses on the wires in the wall or if you do they aren't considered safe? All the appliances have to be individually fused to protect the house wiring from starting a fire.

3A fuses may be an additional safety net. Most things don't get through that but if they do it's about to be on fire and not blowing a main fuse until too late.

[Bill Fitzmaurice]

Assuming the 15 stands for 15 watts it's no more than a 3 amp fuse. 13A at 230v is 2990 watts.

[bode]

Cheers, my hunch was that a 3A would do it. I should have a dozen of these leads lying about in work...but none for tonight's little Friday night beer and bass 'me time'.

[nikon F]

10 hours ago, Downunderwonder said:

 

As I remember you guys don't have fuses on the wires in the wall or if you do they aren't considered safe? 

 

its called a fuse box,,and yes its considered safe ,,,,,

[Downunderwonder]

44 minutes ago, nikon F said:

its called a fuse box,,and yes its considered safe ,,,,,

What is the reason for plugs having their own fuses?

[nikon F]

presumably to protect the cable from the socket to the appliance.

[Bill Fitzmaurice]

There's some logic to fusing the cord. For example, assume that the breaker for the branch circuit that the outlet is on is 10A. Assume that a device plugged in to that outlet is uses a lead that's rated for 5A. A fault in the device or its lead could pull more than 5A, enough to  perhaps start a fire, without tripping the breaker.

[bode]

6 hours ago, Downunderwonder said:

What is the reason for plugs having their own fuses?

When the fuse blows, it disconnects the current and prevents overheating and an electrical fire...from memory.

[TheGreek]

Get a circuit breaker for around a tenner

https://www.ebay.co.uk/itm/392695004255?epid=1804293565&hash=item5b6e723c5f:g:60YAAOSwjzleTpBI

[Bill Fitzmaurice]

That appears to be a ground fault circuit interrupter, GFCI for short. https://simple.wikipedia.org/wiki/Residual-current_device

In the US they're usually built into the wall socket, where they've been a code requirement in kitchens, bathrooms, basements and outdoors for at least 20 years. They're often built into hairdryer leads as well, in the event they're used near a bathroom sink with an old outlet that's not GFCI protected.

 

[Downunderwonder]

NZ has a global GFCI in the breaker box these days.

Still, what's with fuses in UK plugs AND a fuse / breaker box? 

[Bill Fitzmaurice]

I already explained it. It's the same as having a 1000 amp breaker at the nearest breakout transformer, followed by a 100 amp breaker on the service entrance, followed by ten amp breakers at the individual branch circuits. It adds one more layer of redundancy. For whatever reason the UK decided that extra layer of protection was warranted, while most of the rest of the world did not. I guess it's like wearing both a belt and suspenders, you halve the likelihood of your pants falling down. 😉

[Lfalex v1.1]

Does the Amp in question have an internal fuse with a holder on the back panel. 

That will have a rating.

Aim for one of a slightly higher rating than this. 

Example;

My Trace had a 3.15A internal fuse.

I used a 5A fuse in the plug. 

Reason; Trace used a new design of transformer/power supply that was more current- hungry at switch on. It blew fuses again and again. I contacted them and upon their advice moved to a 3.15A spiral-wound slow-blow fuse in the internal holder and a 5A in the plug as it kept doing the 3A ones there as well.

As BFM says, belt and braces, but a pain in the a$$.

[BassmanPaul]

If memory serves me, it HAS been a long time, the UK uses a ring main system. Each branch circuit goes from the breaker loops to the sockets and finally goes back to the breaker. Current flow goes each way from the breaker to the device plugged into the socket. The local fuse in the plug protects what is between the plug and the device. 

Edited June 12, 2021 by BassmanPaul

[agedhorse]

The UK often uses a different type of branch circuit than we do in the states. 

A ring type branch circuit is fed from both ends and even if fused at 10A at each end will result in 20A @240V under a fault condition. The fuse in the plug body is the additional protection for a fault occurring beyond the receptacle.

[BassmanPaul]

Thank you Andy for confirming my memory. LOL

[agedhorse]

2 minutes ago, BassmanPaul said:

Thank you Andy for confirming my memory. LOL

Happy to do so ‘ol man!