Protection is required for every incoming wire to a building
including satellite dish and television antenna. But National
Electrical Code is not concerned with appliance safety. Their
mandate is for human safety. Therefore 'whole house'
protector on phone wires and grounded cable wire is required
by code. 'Whole house' protector for AC electric is not
required. We still build new homes as if the transistor did
not exist. No code exists to protect household appliances.
Therefore homeowner must complete the protection 'system'.
Homeowner must exceed code requirements; install additional
appliance protection on AC electric. Intermatic products
(including the one sold in Home Depot as Intermatic IG1240RC)
can put 'whole house' protection on AC electric. Others are
sold by Leviton, Cutler Hammer, Ditek, Polyphaser, Furse,
Erico and a very long list of other manufacturers. Square D
also sells an integrated 'whole house' protector that does
everything in one rack:
http://makeashorterlink.com/?Z1B7539A1
which should not be confused with an older Square D product
that
is undersized (ineffective).
Earthing is required on every incoming wire. Some cable
companies are now (finally) earthing their cable before
entering the building (a ground connection to outside water
faucet is not acceptable protection). No surge protectors
required to earth the incoming CATV wire. Telco routinely
installs a 'whole house' protector (for free) in the NID of
each customer interface. Again, these are required by code
and therefore (should) exist. But the most common source of
destructive surges is wires highest on utility pole; wires
most often struck - AC electric. For appliance protection, an
AC electric 'whole house' protector is important.