earth bonding

[handyman 44]

hi im doing 12 bed bed and breakfeast . just a 12 piont amp aerial on the roof not rearly rocket science . at the moment there is half a dozen aerials littered around the roof various set back amps . proberly all installed over severall years. proberly before it was turned into a geust house.my Q is will the new installation need to be earth bonded . do u need to get a sparky in to do it.if not is it a hard job to do and if i can do it myself will it be very exspensive .this is my first job on commercial premises all my previous work has been on private dwellings.so any help will be gratefully received

 

[rolfw]

Yes it will need to be earth bonded, you will probably need an electrician to run a 10mm sq earth cable to the head end from the main fuse board, then you simply fit a 12 way earth bonding block and connect your cables onto it. The ones I use have "F" type female to female connectors.

PS. If you are doing this type of installation, you really need to have public liability cover for £5m and for that secilfic type of work.

 

[handyman 44]

thanks for the info i do have liability insurance. i started this line of work about 2 years ago i just moved in with my girl freind. and the tv recepion was rubbish . so i had a go and its kind of snowballed out of proporsion . it was only going to be a little bit of weekend work a little pocket money.but i kind of cant say no no matter how big the job.which in turn has led me to the point where i am now leaving my full time job.to keep up with every thing. but i rearly enjoy the work and wish i did it 20 years ago.now back to the point .would it be ok if i fitted the earth bonding block and ran the cable to the fuse box and get a electrian to connect it up and test .

 

[rolfw]

Should be OK for the earth cable.

With regard to the public liability, you need to make sure that it covers you for this type of installation in particular, mine is for £5m and specifically for aerial, satellite and CCTV, they each needed to be included specifically.

 

[handyman 44]

hi can u get a 12 way earth bonding bar with the f type female to female connectors .do they need to be screened as there seem to be many different types . also how close to the amp should the earth bond be .i was thinking about two feet so i could do all the connections at home.ps checked my certificate and its aerial and sat installations only 2 million . going to up it to five .prior to this installation hoping to do some local council work soon and have been told they require 5 millon cover as well .

 

[rolfw]

The bonding can be pretty much wherever you need it to be, just as long as it is on both sides of the amp, there are several types, the following being the F type with female to female, Triax also do a new flexible one. http://www.dastv.co.uk/viewproduct.aspx?Product=201

 

[spiney]

Agree with everything Rolf says above about earthing, but would just like to add ....

1) The DTG website specifies 6mm sq bonding cable as ok. This is half mains earthing wire diameter, so misleadingly suggests theyr'e saying earthing via equipotential bonding is ok! While not exactly illegal, it's most certainly not a recommended method.

2) Bonding bars with double female sockets make it a lot easier. Only disadvantage is if the client disconnects a particular end-cable, although that doesn't affect the rest of the system earthing.

3) there's also specifications for the actual coax cable, in that it must be able to carry 30A for at least 8 sec before melting! In practise, most sat tv cable would comply (i think they tested how CT100 actually behaves, then made that "the standard"!).

 

[handyman 44]

thanks for all the help my local supplier sell a earth bar with push on connectors one side and f type the other and they line up with the out puts on the amp. the idea is they push straight onto the multiswitch . so there are less connections to be made .

 

[rolfw]

Yes they are good in theory, but can be a little tight to fit on, they need a little encouragement.