Has no ratings. You don't know what you are getting.
Has ratings and ports for phone and antenna.
There is no brand name on either unit. I would only buy a known brand
name like Belkin
The best information on surges and surge protection I have seen is in an
IEEE guide at:
http://omegaps.com/Lightning Guide_FINALpublishedversion_May051.pdf
And also:
http://www.nist.gov/public_affairs/practiceguides/surgesfnl.pdf
The IEEE guide is aimed at those with some technical background. The
NIST guide is aimed at the unwashed masses. Both are written for the US,
but the principles are the same for the UK.
Look
at its numbers. Minimal protectors start at 50,000 amps. And finally
is that little power strip going to stop what three miles of sky could
not?
Plug-in suppressors work by clamping, not stopping. 50,000A might be
useful for a service panel suppressor, although US and UK standards
place the maximum probable surge at 10,000A. The current to a plug-in
suppressor is greatly limited by the impedance of the circuit wiring.
The 9000A value for the 2nd suppressor should be high enough. I would
prefer a higher value, not because the suppressor would see that much
current, but higher current is generally tied to a higher energy (Joule)
rating which gives a longer life.
Not only does that protector not
even claim to protect. It may also create these scary pictures:
http://www.hanford.gov/rl/?page=556&parent=554
The hanford link is about "some older model" power strips and says
overheating was fixed with a revision to UL1449 that requires thermal
disconnects in the US. That was 1998. It is probable that the UK has
also fixed overheating.
But then we have another and the most obvious
reason why it does not even claim to protect. Where is the dedicated
connection to the building earth ground rod? Where does the
manufacturer discuss earthing? No earth ground means no effective
protection.
w_ has a religious belief (immune from challenge) that surge protection
must use earthing. Thus in his view plug-in suppressors (which are not
well earthed) can not possibly work. The IEEE guide explains plug-in
suppressors work by CLAMPING the voltage on all wires (signal and power)
to the common ground at the suppressor. Plug-in suppressors do not work
primarily by earthing (or stopping or absorbing). The guide explains
earthing occurs elsewhere. (Read the guide starting pdf page 40).
Note that all interconnected equipment needs to be connected to the same
plug-in suppressor, or interconnecting wires need to go through the
suppressor. External connections, like phone, also need to go through
the suppressor. Connecting all wiring through the suppressor prevents
damaging voltages between power and signal wires. These multiport
suppressors are described in both guides. Your 2nd suppressor has ports
for phone and antenna.
According to NIST guide, US insurance information indicates equipment
most frequently damaged by lightning is
computers with a modem connection
TVs, VCRs and similar equipment (presumably with cable TV
connections).
All can be damaged by high voltages between power and signal wires.
Service panel suppressors are a good idea.
The NIST guide's comments:
"Q - Will a surge protector installed at the service entrance be
sufficient for the whole house?
A - There are two answers to than question: Yes for one-link appliances,
No for two-link appliances [equipment connected to power AND phone or
CATV or....]. Since most homes today have some kind of two-link
appliances, the prudent answer to the question would be NO - but that
does not mean that a surge protector installed at the service entrance
is useless."
Summarizing ways to protect against surges, the IEEE guide says:
"The previous sections have shown, in general, how to protect electronic
systems in houses:
1) Proper grounding and bonding, especially at the service entrance.
2) AC panel and primary signal surge protection at or near the service
entrance.
3) Multi-port plug-in protectors near the equipment to be protected."
