I am trying to ground a TV aerial. Is it accepted to add the ground wire to the electrical earth wire in my home? Or should I attach the ground wire to my copper water pipe?
You can ground off the electrical ground. Cable companies do this all the time. I would only ground off a pipe if no other options existed.
Note: When cable companies do this, they attach a new saddle joint to the ground. Don't connect to an existing block.
You haven't mentioned where you live, so I'll answer according to National Electrical Code.
First, the lead-in cable from the antenna, must be connected to an antenna discharge unit. This unit is designed to bleed off any static electricity built up on the antenna, to help prevent lightning strikes. The ADU will also have to be bonded to the grounding electrode system of the house.
The mast and ADU must both be bonded to the grounding system of the building. How this is done is described in article 810.21 of the NEC. The conductors used to bond the mast and ADU, must be run in as straight a line as possible (810.21(E)). They must be bonded at the nearest accessible location, to one of the following acceptable locations.
- Intersystem Bonding Terminal
- Any part of the grounding electrode system, as described in 250.50.
- A grounded interior metal pipe system, within 5' of the point of entrance to the building.
- Nonflexible metallic service raceway.
- Service equipment enclosure.
- The grounding electrode conductor or the metallic grounding electrode conductor enclosure.
The conductor(s) used to bond the mast and ADU, shall not be smaller than the following:
- 10 AWG copper
- 8 AWG aluminium
- 17 AWG copper-clad steel or bronze.
Drive a new 8' copper ground rod into the ground. Install a ground clamp that is a suitable size to fit the groud rod, and hook a 10awg bare ground wire to the groud clamp lug, or place it between the ground rod and the clamp. If your close enough to your electric groud then just hook to it like Machavity suggested. Good luck!