Is it safe to cut tv power cable?

[crackers1978]

Very silly question, but I am wall-mounting a tv and I plan to pass the power cable and aerial cable through a small hole in the side of the wardrobe, where the power socket is situated.

To do this I will need to cut the cable and then re-connect it inside the wardrobe with a cable connector.

I remember being told years ago that tvs contain a capacitor which retains a charge after it is switched off. So might it be dangerous to cut the power cable?

Thanks in advance.

 

[Monkeh]

All the main caps in a modern TV should have bleed resistors, and even if it doesn't, the filter cap is highly unlikely to be dangerous. The HV caps in CRTs were extremely dangerous, but you don't have to worry about that.

If the cable is long enough, just cut it at the end and fit a new plug. A cable connector is needless extra terminations. Don't forget to fit the right fuse.

 

[crackers1978]

Brilliant, thanks Monkeh.

The reason I am going for the connector is I heard that the moulded plug contains some sort of radio interference filter?

 

[HERTS P&D]

Don't cut the TV cable when it is plugged in.

Andy

 

[crackers1978]

Thanks Hertsdrainage I'll bear that in mind

 

[Monkeh]

Brilliant, thanks Monkeh.

The reason I am going for the connector is I heard that the moulded plug contains some sort of radio interference filter?

Bull, they do that in the TV itself.

 

[wotan]

Very silly question, but I am wall-mounting a tv and I plan to pass the power cable and aerial cable through a small hole in the side of the wardrobe, where the power socket is situated.

To do this I will need to cut the cable and then re-connect it inside the wardrobe with a cable connector.

I remember being told years ago that tvs contain a capacitor which retains a charge after it is switched off. So might it be dangerous to cut the power cable?

Thanks in advance.

If you are worried about retained charge, just bridge the live and neutral prongs of the plug to each other, in all probabilities there will not be a earth wire connected.

Wotan

 

[Monkeh]

Very silly question, but I am wall-mounting a tv and I plan to pass the power cable and aerial cable through a small hole in the side of the wardrobe, where the power socket is situated.

To do this I will need to cut the cable and then re-connect it inside the wardrobe with a cable connector.

I remember being told years ago that tvs contain a capacitor which retains a charge after it is switched off. So might it be dangerous to cut the power cable?

Thanks in advance.

If you are worried about retained charge, just bridge the live and neutral prongs of the plug to each other, in all probabilities there will not be a earth wire connected.

Wotan

I'm afraid I must dispute that claim. Any good quality TV or monitor will have an earth for shielding and reduction of RFI.

 

[wotan]

Very silly question, but I am wall-mounting a tv and I plan to pass the power cable and aerial cable through a small hole in the side of the wardrobe, where the power socket is situated.

To do this I will need to cut the cable and then re-connect it inside the wardrobe with a cable connector.

I remember being told years ago that tvs contain a capacitor which retains a charge after it is switched off. So might it be dangerous to cut the power cable?

Thanks in advance.

If you are worried about retained charge, just bridge the live and neutral prongs of the plug to each other, in all probabilities there will not be a earth wire connected.

Wotan

I'm afraid I must dispute that claim. Any good quality TV or monitor will have an earth for shielding and reduction of RFI.

Point conceeded, you are right, I was thinking along the lines of double insulated equipment..

Wotan

 

[Monkeh]

Point conceeded, you are right, I was thinking along the lines of double insulated equipment..

Wotan

Indeed, but that's only the cheapo crap.

 

[plugwash]

I've noticed a lot more equipment with earth connections than there used to be.

I believe the reason for this is that class 2 SMPSUs have a fundamental compromise between safety (of both people and equipment) and EMI. To reduce EMI you want capacitors between input and output but those capacitors cause problems. They mean that the open circuit common mode voltage of the output will tend to arround half the supply voltage (assuming a symetrical design) and that if something connects the output to earth then current will flow through it.

If the capacitors are small enough and are of an appropriate safety rated type such that the chance of them failing short-circuit can be considered negligable then the current should not be hazardous to humans but it can still cause perceptable shocks and it can still be hazardous to equipment.

Furthermore beyond a certain power rating it becomes very difficult to find a capacitor that is both safe to use in this manner and capable of suppressing the interference.

Class 1 SMPSUs can put the capacitors between input and earth and between output and earth (or just tie the output directly to earth like PC PSUs do) so that provided the earth is good they don't pose a shock threat to users.

 

[knobby41]

it might be a silly question, but what make of tv is it, and are you sure that its not connected with a figure 8 or a kettle lead?

cutting the plug off wont affect any warantee whether you have extended or manufacturers

whatever you do, remember to put a 5 amp fuse back in the plug to protect it properly.
(wallmount tvs all the time so no probs)

ta

 

[Monkeh]

it might be a silly question, but what make of tv is it, and are you sure that its not connected with a figure 8 or a kettle lead?

Even if it is that's a huge hole to drill compared to one for the cable itself.

 

[knobby41]

lol. fig 8 leads are approx 12mm. at least you know the connection is safe.

good point tho!

 

[Monkeh]

lol. fig 8 leads are approx 12mm. at least you know the connection is safe.

good point tho!

Do you? There's no way to look inside a moulded connector.