Do I need fuses in my cables or power strip?

[Rantenti]

Hello all,

I am feeding my audio equipment (desktop computer, Gustard x26 pro DAC, Topping A90 amp, Neumann active speakers) with a power strip which has a 10A fuse and claimed surge protection from a home electronics shop, which is plugged into a wall socket which has a 13A fuse.

I wonder if I need further fuses to protect each of my equipment like in my cables, but it seems only the UK type plug has a fuse inside.

Thanks!

 

[solderdude]

Each device should have its own fuse or depends on the fuses in your fuse box.
A fuse is there not to protect the device itself but to ensure the device itself does not burn to a crisp and to prevent the mains to be shorted and burn the wiring in your wall.

You can add as many fuses in series you want. One of them is usually the fastest or weakest and will go first.
The ones in your fuse box are slow so they will only 'blow' when all else has failed.

The reason for the UK fuses in a cable is simple. It will protect the mains and the mains fuse when accidentally the cable is damaged and shorts (even without any device connected to it).
Probably a 'law' thing ...

 

[Frgirard]

Hello all,

I am feeding my audio equipment (desktop computer, Gustard x26 pro DAC, Topping A90 amp, Neumann active speakers) with a power strip which has a 10A fuse and claimed surge protection from a home electronics shop, which is plugged into a wall socket which has a 13A fuse.

I wonder if I need further fuses to protect each of my equipment like in my cables, but it seems only the UK type plug has a fuse inside.

Thanks!

The fuse is made to protect you against your setup.

 

[mansr]

The reason for the UK fuses in a cable is simple. It will protect the mains and the mains fuse when accidentally the cable is damaged and shorts (even without any device connected to it).
Probably a 'law' thing ...

The fuses in the distribution panel protect the in-wall wiring. British plugs have fuses to protect the power lead since the main fuses typically have a much higher rating (32 A in my flat). A power lead rated for, say, 5 A could become dangerously hot without the main fuse blowing.

 

[Rantenti]

The fuses in the distribution panel protect the in-wall wiring. British plugs have fuses to protect the power lead since the main fuses typically have a much higher rating (32 A in my flat). A power lead rated for, say, 5 A could become dangerously hot without the main fuse blowing.

Thanks! I am wondering how people in countries using non-UK plugs can insert additional fuses (eg. 5A or 10A) between the mains and their equipment as there is no place in the power cord plugs that a fuse could be inserted, and that some equipment, eg. the Neumann kh80 active speakers, do not seem to be fitted with a fuse AFAIK, and are also not grounded.

 

[Speedskater]

the Neumann kh80 active speakers, do not seem to be fitted with a fuse AFAIK, and are also not grounded.

Many modern components use a safety tested double insulated construction method (square within a square safety symbol). They are not designed to be grounded. In fact it could be vary dangerous to modify some by adding a ground.

 

[DonH56]

Most if not all equipment is already fused and/or has protection built in. I would not bother adding additional in-line fuses.

Grounding is a tricky subject. In general I would not add a ground to say the chassis of an insulated (two-prong) device; that could defeat the safety feature that allowed the use of a two-prong connection and actually make it less safe.

Edit: @Speedskater beat me to it...

 

[Rantenti]

Many modern components use a safety tested double insulated construction method (square within a square safety symbol). They are not designed to be grounded. In fact it could be vary dangerous to modify some by adding a ground.

Oh I see! Thanks a million for this safety tip!

Actually, I have an ungrounded router that comes with a two pronged plug and it is causing my system to hum and buzz (the noise disappears whenever I touch the router or unplug it). What I could do since I have no other wall socket I could use for the router and modifying it to add a ground might be dangerous.

Thanks!

 

[mansr]

Actually, I have an ungrounded router that comes with a two pronged plug and it is causing my system to hum and buzz (the noise disappears whenever I touch the router or unplug it). What I could do since I have no other wall socket I could use for the router and modifying it to add a ground might be dangerous.

Flip the plug around. It might help.

 

[Rantenti]

Flip the plug around. It might help.

I'll try that. Any other remedies if it doesn't work please?

 

[AnalogSteph]

I am puzzled as to why this should be affecting your equipment at all if it's this:

my audio equipment (desktop computer, Gustard x26 pro DAC, Topping A90 amp, Neumann active speakers)

with, presumably, XLR cables of somewhat decent quality. All these components should be IEC Class I (earthed) devices with balanced connections. Unless your mains wiring is entirely lacking a proctective earth connection (where are you located and how old is it?), I can only imagine an RF ingress problem in one of the components - does moving the router around make any difference?

 

[Rantenti]

I am puzzled as to why this should be affecting your equipment at all if it's this:

with, presumably, XLR cables of somewhat decent quality. All these components should be IEC Class I (earthed) devices with balanced connections. Unless your mains wiring is entirely lacking a proctective earth connection (where are you located and how old is it?), I can only imagine an RF ingress problem in one of the components - does moving the router around make any difference?

Hello and thanks for your reply!

I had been using RCA cables (stock cables / Mogami 2497) between the DAC and A90, then XLR cables from A90 to the Neumann KH 80.

Buzzing noises could be softly heard on the Neumann, and it was very loud when I used IEMs plugged into the Topping A90.

1. I added an ifi iDefender to the USB cable, 90% of the noise is gone. This showed that there was a ground loop. Still some noise remained.

2. The remaining noise waxed and waned with GPU usage (eg. playing a video without sound), so there must be some EMI noise as well. Moving the A90 away from the computer and router lessened this noise. Moving the Gustard X26 Pro had no effect, perhaps due to shielding by the thick aluminum casing.

3. Occassionally, there was an extra 1kHz whine and intermittent buzz that the iDefender couldn't remove. I unplugged the router, it disappeared So the router (which was ungrounded), must be one of the culprits of noise too.

Today, I received my much needed second pair of XLR cables and now both my DAC-Amp and Amp-Neumann connections are Mogami 2549 XLR. All noises are gone, even without the iDefender.

There are a few interesting observations.

1. If I connect the DAC and the A90 with BOTH RCA and XLR cables in place, even if I choose XLR input on the A90, all the buzzing comes back.

2. The Wifi router related noise could not be replicated now, after I unplugged the router and all the LAN cables and replugged them in. I hope they don't come back.

3. The if iPurifier doesn't always reduce noise. In my previous configuration where the iDefender reduced 90% of the ground loop noise, adding an iPurifier to the USB gave me double the noise.

Finally, all my equipment are plugged by UK plugs (except the router) into two power strips (Belkin/ Schneider) going into ONE wall socket via a multi-plug adapter. My apartment block is only a few years old and the UK plugged wall socket is grounded by law.

Happy to share my experience and to learn from you all.

 

[Suffolkhifinut]

The fuses in the distribution panel protect the in-wall wiring. British plugs have fuses to protect the power lead since the main fuses typically have a much higher rating (32 A in my flat). A power lead rated for, say, 5 A could become dangerously hot without the main fuse blowing.

The fuse in the plug is there to protect the cord set not the equipment. The fuse in the distribution board is there to protect the circuit‘s fixed wiring. The UK fused plug system only came into being when ring main wiring was adopted. Most other countries wire their socket outlets on radial circuits. Radial circuits are still used in the UK, BS7671 still required the use of the fused 13A plug. When cartridge fuses were brought out for use in 13 Amp plugs, 1A, 3A, 5A, 7A, 10A, 13A were widely sold. This led to confusion so now there are two recommended ratings, 3A and 13 A. The 3A is suitable for loads not exceeding 700 Watts, the 13A for loads exceeding this up to 3kW.

 

[Audiofire]

Thanks! I am wondering how people in countries using non-UK plugs can insert additional fuses (eg. 5A or 10A) between the mains and their equipment

Surge protector. A good idea that protects against voltage spikes from both outside and inside the building. But dangerous overcurrent should not occur under normal circumstances, and a surge protector is not even used by most people (in Denmark).

 

[EdTice]

Surge protector. A good idea that protects against voltage spikes from both outside and inside the building. But dangerous overcurrent should not occur under normal circumstances, and a surge protector is not even used by most people (in Denmark).

In the US, if the device and power cord are both safety rated, its sufficient to have a fuse in the device. You don't need it at the outlet level. @Suffolkhifinut s explanation was interesting and informative for those of us in North America. The only way a surge protector helps in the event of something like a lighting strike is if it is faster than the fuse in your device (which it might be). I don't know why the cords are considered "safe." Presumably, even though the cord itself is rated for less than 15amps, there is enough insulation to prevent it from causing a fire if you exceed the rated load. You don't have to be an expert on these things if you follow Amir's advice and buy things that are third-party safety certified!

 

[Audiofire]

In the US, if the device and power cord are both safety rated, its sufficient to have a fuse in the device. You don't need it at the outlet level. @Suffolkhifinut s explanation was interesting and informative for those of us in North America. The only way a surge protector helps in the event of something like a lighting strike is if it is faster than the fuse in your device (which it might be). I don't know why the cords are considered "safe." Presumably, even though the cord itself is rated for less than 15amps, there is enough insulation to prevent it from causing a fire if you exceed the rated load. You don't have to be an expert on these things if you follow Amir's advice and buy things that are third-party safety certified!

Common causes of power surges:

• Lighting/electrical storms
• Downed power lines
• Faulty wiring
• Power outages
• Large appliances cycling on or off
• Power plant maintenance
• Bad electrical components

Source:

Surge Protector vs. Circuit Breaker: What’s the Difference? – Energy Today Electricians

Learn about the differences between a surge protector and a circuit breaker.

energytoday.biz

So way more than just some random lightning strike though. After a power outage, there can be a surge that can damage equipment. A surge protector is certainly a nice way to get peace of mind.

 

[Suffolkhifinut]

In the US, if the device and power cord are both safety rated, its sufficient to have a fuse in the device. You don't need it at the outlet level. @Suffolkhifinut s explanation was interesting and informative for those of us in North America. The only way a surge protector helps in the event of something like a lighting strike is if it is faster than the fuse in your device (which it might be). I don't know why the cords are considered "safe." Presumably, even though the cord itself is rated for less than 15amps, there is enough insulation to prevent it from causing a fire if you exceed the rated load. You don't have to be an expert on these things if you follow Amir's advice and buy things that are third-party safety certified!

Fuses generally are ‘Too late protective devices.’ You can buy quick blow types although they not might be suitable for electrical devices were short duration high currents are in their normal operation. Have used Germanium based fuses industrially they do blow quickly enough to give fast overcurrent protection, but at a cost! Surge protection is an entirely different thing.

 

[Katji]

It's not about lightning strikes, more about what happens with unstable power and especially what happens when the power is switched on after a load shedding period or "unplanned maintenance."

 

[Audiofire]

It's not even just about surges if we are talking about protecting electronics. Voltage sags are probably way more common and can happen when something on the electrical utility grid draws a lot of power, and that is usually in terms of inrush current. Fact is I switched over to solely using my laptop, and one of the reasons is a lightning strike came in all the way to my desktop computer from the ethernet cable (literally destroyed the router and connected network switch, and a laptop is pretty safe from unstable AC mains and has Wi-Fi plus it can solve problems with ground loops in hi-fi anyway).

 

[voodooless]

British plugs have fuses to protect the power lead since the main fuses typically have a much higher rating (32 A in my flat)

Once on holiday in the UK, I inspected the electrical system of the apartment we rented. The only fuse except for the ones in the plugs was 100A main fuse. Crazy stuff!