Small commumal sat systems - safety

Sky is offering to put free communal dishes in flatted tenement
properties near me with a view to drumming up business.

The systems feed 8 flats each and there would be a mini head end
outdoors by the dish.

One query I raised was about power feed for the head end which I was
told would be via the set top boxes.

I'm guessing that the head end and LNB will be powered via any STB that
is powered up but I was concerned about isolation between the power
feeds going into the head end box, could a power feed fault from one
faulty STB result damage or danger to the other subscribers equipment?

We've been informed that the head end would be earthed to a spike at
ground level.
--
fred
FIVE TV's superbright logo - not the DOG's, it's ********

On 13/01/2011 11:56, fred wrote:
Sky is offering to put free communal dishes in flatted tenement
properties near me with a view to drumming up business.

The systems feed 8 flats each and there would be a mini head end
outdoors by the dish.

One query I raised was about power feed for the head end which I was
told would be via the set top boxes.

I'm guessing that the head end and LNB will be powered via any STB that
is powered up but I was concerned about isolation between the power
feeds going into the head end box, could a power feed fault from one
faulty STB result damage or danger to the other subscribers equipment?

We've been informed that the head end would be earthed to a spike at
ground level.

I doubt that's correct.
Who told you this?

A standard LNB gets it's power from the reciever, but that won't power
up a multiswitch ( the 'head end' ). That will require 240v at the
head end.

In a communal system, there will be a earth bonding strip which each of
the feeds down to the flats will pass through. This will be bonded
back to the building's main earth, in the same manner as main bonding
for incoming water and gas.



--
Ron

fred wrote:
Sky is offering to put free communal dishes in flatted tenement
properties near me with a view to drumming up business.

The systems feed 8 flats each and there would be a mini head end
outdoors by the dish.

One query I raised was about power feed for the head end which I was
told would be via the set top boxes.

I'm guessing that the head end and LNB will be powered via any STB that
is powered up but I was concerned about isolation between the power
feeds going into the head end box, could a power feed fault from one
faulty STB result damage or danger to the other subscribers equipment?

We've been informed that the head end would be earthed to a spike at
ground level.
That's what they do in theory with these unpowered systems, but I
suggest you get a sparks to check for resistance between the multiswitch
case and ground. I've seen these jobs done with a 'joke' earth
connection. Incidentally the enclosure will be locked. Tell the
installers you want a key and if they say no tell they to bugger off.
It's all a scam to overcharge for extra connections later. It's rife.

Bill

In article , Ron Lowe
writes
On 13/01/2011 11:56, fred wrote:
Sky is offering to put free communal dishes in flatted tenement
properties near me with a view to drumming up business.

The systems feed 8 flats each and there would be a mini head end
outdoors by the dish.

One query I raised was about power feed for the head end which I was
told would be via the set top boxes.

I'm guessing that the head end and LNB will be powered via any STB that
is powered up but I was concerned about isolation between the power
feeds going into the head end box, could a power feed fault from one
faulty STB result damage or danger to the other subscribers equipment?

We've been informed that the head end would be earthed to a spike at
ground level.

I doubt that's correct.
Who told you this?

Unfortunately it was the installer.

A standard LNB gets it's power from the reciever, but that won't power
up a multiswitch ( the 'head end' ). That will require 240v at the
head end.

Indeed, having been round here a bit, that is what I was expecting but
see Bill's reply that it is not uncommon.

In a communal system, there will be a earth bonding strip which each of
the feeds down to the flats will pass through. This will be bonded
back to the building's main earth, in the same manner as main bonding
for incoming water and gas.

I had thought that a spike would be adequate but I see your point of
cross bonding.

It is a moot point now as after discussing it with the installer the
owners are of the view that the quality trade-offs likely with a 'free'
job would lead to higher costs in future maintenance and so have turned
it down.
--
fred
FIVE TV's superbright logo - not the DOG's, it's ********

In article , Bill Wright
writes
fred wrote:
Sky is offering to put free communal dishes in flatted tenement
properties near me with a view to drumming up business.

The systems feed 8 flats each and there would be a mini head end
outdoors by the dish.

One query I raised was about power feed for the head end which I was
told would be via the set top boxes.

I'm guessing that the head end and LNB will be powered via any STB that
is powered up but I was concerned about isolation between the power
feeds going into the head end box, could a power feed fault from one
faulty STB result damage or danger to the other subscribers equipment?

We've been informed that the head end would be earthed to a spike at
ground level.

That's what they do in theory with these unpowered systems, but I
suggest you get a sparks to check for resistance between the multiswitch
case and ground. I've seen these jobs done with a 'joke' earth
connection. Incidentally the enclosure will be locked. Tell the
installers you want a key and if they say no tell they to bugger off.
It's all a scam to overcharge for extra connections later. It's rife.

Thanks for the info & tips. The owners have said thanks but no thanks as
they weren't happy with the reassurances on cable routing and quality of
installation on a 'free' job.

One lovely quote, "there is no power, it's powered off the LNB",
"Oh, really" . . .
--
fred
FIVE TV's superbright logo - not the DOG's, it's ********

"fred" wrote in message ...
In article , Bill Wright writes
fred wrote:
Sky is offering to put free communal dishes in flatted tenement
properties near me with a view to drumming up business.

The systems feed 8 flats each and there would be a mini head end
outdoors by the dish.

One query I raised was about power feed for the head end which I was
told would be via the set top boxes.

I'm guessing that the head end and LNB will be powered via any STB that
is powered up but I was concerned about isolation between the power
feeds going into the head end box, could a power feed fault from one
faulty STB result damage or danger to the other subscribers equipment?

We've been informed that the head end would be earthed to a spike at
ground level.

That's what they do in theory with these unpowered systems, but I
suggest you get a sparks to check for resistance between the multiswitch
case and ground. I've seen these jobs done with a 'joke' earth
connection. Incidentally the enclosure will be locked. Tell the
installers you want a key and if they say no tell they to bugger off.
It's all a scam to overcharge for extra connections later. It's rife.

Thanks for the info & tips. The owners have said thanks but no thanks as they weren't happy with the reassurances on cable routing
and quality of installation on a 'free' job.

One lovely quote, "there is no power, it's powered off the LNB",
"Oh, really" . . .

Strategically placed mugs of hot coffee might do it.

--
Graham.

%Profound_observation%

Ron Lowe wrote:

I'm guessing that the head end and LNB will be powered via any STB that
is powered up but I was concerned about isolation between the power
feeds going into the head end box, could a power feed fault from one
faulty STB result damage or danger to the other subscribers equipment?

We've been informed that the head end would be earthed to a spike at
ground level.

I doubt that's correct.
Who told you this?

A standard LNB gets it's power from the reciever, but that won't power
up a multiswitch ( the 'head end' ). That will require 240v at the
head end.

No, these ****ty systems don't need mains.

Bill

fred wrote:

It is a moot point now as after discussing it with the installer the
owners are of the view that the quality trade-offs likely with a 'free'
job would lead to higher costs in future maintenance and so have turned
it down.

Hurrah! I wish more people had that much sense. Do you remember that pic
I posted of a dish reflector swinging loose in the wind?

Bill

Graham. wrote:

One lovely quote, "there is no power, it's powered off the LNB",
"Oh, really" . . .

Strategically placed mugs of hot coffee might do it.

Ha ha!

Bill

In article , Bill Wright
writes
fred wrote:

It is a moot point now as after discussing it with the installer the
owners are of the view that the quality trade-offs likely with a 'free'
job would lead to higher costs in future maintenance and so have turned
it down.

Hurrah! I wish more people had that much sense. Do you remember that pic
I posted of a dish reflector swinging loose in the wind?

They're quite a savvy bunch but they did have the benefit of my
advice[1] too :-D

The swinging reflector doesn't ring a bell but I have been through the
library in detail so will have seen it.

[1] Credit where credit is due, based mainly on knowledge gleaned from
here.
--
fred
FIVE TV's superbright logo - not the DOG's, it's ********