A warning to aerial installers! My son Paul removed an old aerial from
the chimney and put it down on the roof, where it happened to touch the
frame of a solar panel. When he picked it up he received a severe
electric shock and he was lucky he wasn’t thrown off the roof. Obviously
the solar installation wasn’t properly earthed. Needless to say he
warned the householder that his solar installation was faulty, which
didn’t please him at all. I suggest everyone working on roofs treats
solar panels as a lethal shock hazard until proven otherwise. The last
thing you want when working at heights is an electric shock.

In the early days of television every TV and radio aerial was assumed to
be ‘live’. Maybe we need to go back to those days and work in rubber
gloves.

It was quite serious. Paul said the shock felt like 240V 50Hz, so it's
likely the whole installation wasn't earthed. The high voltage from the
panels is DC of course, but Paul said he definitely felt the 50Hz! I
asked how many Hz he counted before he let go but he said he wasn't sure!

Of course the solar industry is full of bloody cowboys, so it's no
surprise. Some of the roof fixings they've used (that we've seen) are
terrible. There's going to be a legacy of leaking roofs in a few years.
That'll extend the payback time to infinity I should think!

Bill

On Wednesday 03 July 2013 15:18 Bill Wright wrote in uk.d-i-y:

A warning to aerial installers! My son Paul removed an old aerial from
the chimney and put it down on the roof, where it happened to touch the
frame of a solar panel. When he picked it up he received a severe
electric shock and he was lucky he wasnt thrown off the roof. Obviously
the solar installation wasnt properly earthed. Needless to say he
warned the householder that his solar installation was faulty, which
didnt please him at all. I suggest everyone working on roofs treats
solar panels as a lethal shock hazard until proven otherwise. The last
thing you want when working at heights is an electric shock.

In the early days of television every TV and radio aerial was assumed to
be €˜live. Maybe we need to go back to those days and work in rubber
gloves.

It was quite serious. Paul said the shock felt like 240V 50Hz, so it's
likely the whole installation wasn't earthed. The high voltage from the
panels is DC of course, but Paul said he definitely felt the 50Hz! I
asked how many Hz he counted before he let go but he said he wasn't sure!

Of course the solar industry is full of bloody cowboys, so it's no
surprise. Some of the roof fixings they've used (that we've seen) are
terrible. There's going to be a legacy of leaking roofs in a few years.
That'll extend the payback time to infinity I should think!

Bill

If it helps, a nearby bungalow has PV panels and I can see 2 green/yellow
earth bonding wires coming off the panel frame. Looks like 6mm2 +/-

So yours sounds like a buggered installation.

--
Tim Watts Personal Blog: http://squiddy.blog.dionic.net/

http://www.sensorly.com/ Crowd mapping of 2G/3G/4G mobile signal coverage

Reading this on the web? See:
http://wiki.diyfaq.org.uk/index.php?title=Usenet

I blame the squirrels myself, always eating away outdoor wires, can't see
what they see in them.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Tim Watts" wrote in message
...
On Wednesday 03 July 2013 15:18 Bill Wright wrote in uk.d-i-y:

A warning to aerial installers! My son Paul removed an old aerial from
the chimney and put it down on the roof, where it happened to touch the
frame of a solar panel. When he picked it up he received a severe
electric shock and he was lucky he wasn't thrown off the roof. Obviously
the solar installation wasn't properly earthed. Needless to say he
warned the householder that his solar installation was faulty, which
didn't please him at all. I suggest everyone working on roofs treats
solar panels as a lethal shock hazard until proven otherwise. The last
thing you want when working at heights is an electric shock.

In the early days of television every TV and radio aerial was assumed to
be 'live'. Maybe we need to go back to those days and work in rubber
gloves.

It was quite serious. Paul said the shock felt like 240V 50Hz, so it's
likely the whole installation wasn't earthed. The high voltage from the
panels is DC of course, but Paul said he definitely felt the 50Hz! I
asked how many Hz he counted before he let go but he said he wasn't sure!

Of course the solar industry is full of bloody cowboys, so it's no
surprise. Some of the roof fixings they've used (that we've seen) are
terrible. There's going to be a legacy of leaking roofs in a few years.
That'll extend the payback time to infinity I should think!

Bill

If it helps, a nearby bungalow has PV panels and I can see 2 green/yellow
earth bonding wires coming off the panel frame. Looks like 6mm2 +/-

So yours sounds like a buggered installation.

--
Tim Watts Personal Blog: http://squiddy.blog.dionic.net/

http://www.sensorly.com/ Crowd mapping of 2G/3G/4G mobile signal coverage

Reading this on the web? See:
http://wiki.diyfaq.org.uk/index.php?title=Usenet

"Bill Wright" wrote in message
...
A warning to aerial installers! My son Paul removed an old aerial from the
chimney and put it down on the roof, where it happened to touch the frame
of a solar panel. When he picked it up he received a severe electric shock
and he was lucky he wasn’t thrown off the roof. Obviously the solar
installation wasn’t properly earthed. Needless to say he warned the
householder that his solar installation was faulty, which didn’t please him
at all. I suggest everyone working on roofs treats solar panels as a lethal
shock hazard until proven otherwise. The last thing you want when working
at heights is an electric shock.

In the early days of television every TV and radio aerial was assumed to
be ‘live’. Maybe we need to go back to those days and work in rubber
gloves.

It was quite serious. Paul said the shock felt like 240V 50Hz, so it's
likely the whole installation wasn't earthed. The high voltage from the
panels is DC of course, but Paul said he definitely felt the 50Hz! I asked
how many Hz he counted before he let go but he said he wasn't sure!

Of course the solar industry is full of bloody cowboys, so it's no
surprise. Some of the roof fixings they've used (that we've seen) are
terrible. There's going to be a legacy of leaking roofs in a few years.
That'll extend the payback time to infinity I should think!

Bill

Not quite as simple as that. It is a controversial topic.
Bit here on the subject.
http://www.energymatters.com.au/rene...nel-frames.php


There's no reason why a roof should leak if the job is done properly.

harryagain wrote:

There's no reason why a roof should leak if the job is done properly.

Well, any penetration of a roof is likely to fail eventually. But I did
mention my suspicion that the job hadn't been done to the highest standards.

I think the problem with solar panels is that there is a large number of
small holes made, so the chance of failure on a whole installation is high.

Without doubt a 'clean' roof with no attachments or penetrations is
likely to prove the most reliable, and cheapest to fix if there is a
problem.

Bill

On 03/07/2013 19:38, Bill Wright wrote:
harryagain wrote:

There's no reason why a roof should leak if the job is done properly.

Well, any penetration of a roof is likely to fail eventually. But I did
mention my suspicion that the job hadn't been done to the highest
standards.

I think the problem with solar panels is that there is a large number of
small holes made, so the chance of failure on a whole installation is high.


There shouldn't be any new holes.
The idea is too remove a tile/slate and fit a hanger bracket.
The tile/slate is then refitted without any new holes.
Repeat as required.

The rails fix to the brackets and the panels to the rails.

dennis@home wrote:
On 03/07/2013 19:38, Bill Wright wrote:
harryagain wrote:

There's no reason why a roof should leak if the job is done properly.

Well, any penetration of a roof is likely to fail eventually. But I did
mention my suspicion that the job hadn't been done to the highest
standards.

I think the problem with solar panels is that there is a large number of
small holes made, so the chance of failure on a whole installation is
high.


There shouldn't be any new holes.
The idea is too remove a tile/slate and fit a hanger bracket.
The tile/slate is then refitted without any new holes.
Repeat as required.

The rails fix to the brackets and the panels to the rails.

You can't 'remove' individual tiles (and even more so slates) if the
roof has been properly nailed. A good slate roof is as tight as my
brother-in-law. No, sorry, I'm exaggerating. But it really is tight.
Believe me, I've been trying to find ways to route cables through roofs
for the last 40 years. If you start lifting individual tiles and slates
(even if you can, which on a well-nailed roof you won't be able to)
you'll never get the roof back to as good as it was before.
What happens if you try to force the issue with a nailed roof? Well you
will break a lot of tiles or slates.
If you do manage to slide a hanger bracket under a tile you won't be
able to nail it, and it's no good saying you'll go in the loft to do it
because of the roofing felt. So the only thing stabilising the hanger is
the weight of the tile. Wind gets under tiles and lifts them, and I've
no doubt it will get under solar panels. Constant movement is the enemy
of a sound roof.
On roofs with a gentle pitch there's always the danger of rain blowing
up under the slates, or getting sucked though due to pressure
differentials. Seen this many a time. Even a slim hanger bracket will
make this much more likely.
I've seen a lot of solar installations fixed by drilling holes through
the slates above the rafters and inserting a long bolt-thing with a
screw tip. Waterproofing is by a tight-fitting rubber grommet. It's
obvious that this arrangement is going to fail long before the panels
are worn out.
When you stand on the ground and look up at panels they look OK. But
climb up there and get hold of them and you'll often find they're quite
loose, and can be lifted up with ease, bringing tiles with them.
The solar panel job, like the aerial job, is difficult for the customer
to have a close look at, so bad work is rife.

It will end in tears believe me. Give it a few years and the **** will
hit the fan.

Bill

On 03/07/2013 20:42, Bill Wright wrote:

You can't 'remove' individual tiles (and even more so slates) if the
roof has been properly nailed. A good slate roof is as tight as my
brother-in-law. No, sorry, I'm exaggerating. But it really is tight.

With a proper slated roof, then you can use a tool called a "slater's
rip" to cut through the nails in one slate and free it such that it can
be slid out. You then need to use a repair bracket (or lead strip) to
refix it since you can't get the nails back in once its in place.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 03/07/2013 20:42, Bill Wright wrote:
dennis@home wrote:
On 03/07/2013 19:38, Bill Wright wrote:
harryagain wrote:

There's no reason why a roof should leak if the job is done properly.

Well, any penetration of a roof is likely to fail eventually. But I did
mention my suspicion that the job hadn't been done to the highest
standards.

I think the problem with solar panels is that there is a large number of
small holes made, so the chance of failure on a whole installation is
high.


There shouldn't be any new holes.
The idea is too remove a tile/slate and fit a hanger bracket.
The tile/slate is then refitted without any new holes.
Repeat as required.

The rails fix to the brackets and the panels to the rails.

You can't 'remove' individual tiles (and even more so slates) if the
roof has been properly nailed. A good slate roof is as tight as my
brother-in-law. No, sorry, I'm exaggerating. But it really is tight.
Believe me, I've been trying to find ways to route cables through roofs
for the last 40 years. If you start lifting individual tiles and slates
(even if you can, which on a well-nailed roof you won't be able to)
you'll never get the roof back to as good as it was before.
What happens if you try to force the issue with a nailed roof? Well you
will break a lot of tiles or slates.


Sorry but you don't appear to understand roof construction or working
methods.

I have just had some of the tiles removed and a mains pressure cylinder
dropped in and its pretty easy to remove tiles as they aren't nailed
every row.

Roofers frequently remove and repair slates too, using a slate ripper.

"Bill Wright" wrote in message
...
dennis@home wrote:
On 03/07/2013 19:38, Bill Wright wrote:
harryagain wrote:

There's no reason why a roof should leak if the job is done properly.

Well, any penetration of a roof is likely to fail eventually. But I did
mention my suspicion that the job hadn't been done to the highest
standards.

I think the problem with solar panels is that there is a large number of
small holes made, so the chance of failure on a whole installation is
high.


There shouldn't be any new holes.
The idea is too remove a tile/slate and fit a hanger bracket.
The tile/slate is then refitted without any new holes.
Repeat as required.

The rails fix to the brackets and the panels to the rails.

You can't 'remove' individual tiles (and even more so slates) if the roof
has been properly nailed. A good slate roof is as tight as my
brother-in-law. No, sorry, I'm exaggerating. But it really is tight.
Believe me, I've been trying to find ways to route cables through roofs
for the last 40 years. If you start lifting individual tiles and slates
(even if you can, which on a well-nailed roof you won't be able to) you'll
never get the roof back to as good as it was before.
What happens if you try to force the issue with a nailed roof? Well you
will break a lot of tiles or slates.
If you do manage to slide a hanger bracket under a tile you won't be able
to nail it, and it's no good saying you'll go in the loft to do it because
of the roofing felt. So the only thing stabilising the hanger is the
weight of the tile. Wind gets under tiles and lifts them, and I've no
doubt it will get under solar panels. Constant movement is the enemy of a
sound roof.
On roofs with a gentle pitch there's always the danger of rain blowing up
under the slates, or getting sucked though due to pressure differentials.
Seen this many a time. Even a slim hanger bracket will make this much more
likely.
I've seen a lot of solar installations fixed by drilling holes through the
slates above the rafters and inserting a long bolt-thing with a screw tip.
Waterproofing is by a tight-fitting rubber grommet. It's obvious that this
arrangement is going to fail long before the panels are worn out.
When you stand on the ground and look up at panels they look OK. But climb
up there and get hold of them and you'll often find they're quite loose,
and can be lifted up with ease, bringing tiles with them.
The solar panel job, like the aerial job, is difficult for the customer to
have a close look at, so bad work is rife.

It will end in tears believe me. Give it a few years and the **** will hit
the fan.

Bill


Are you listening, Harry ?

Arfa

"Bill Wright" wrote in message
...
dennis@home wrote:
On 03/07/2013 19:38, Bill Wright wrote:
harryagain wrote:

There's no reason why a roof should leak if the job is done properly.

Well, any penetration of a roof is likely to fail eventually. But I did
mention my suspicion that the job hadn't been done to the highest
standards.

I think the problem with solar panels is that there is a large number of
small holes made, so the chance of failure on a whole installation is
high.


There shouldn't be any new holes.
The idea is too remove a tile/slate and fit a hanger bracket.
The tile/slate is then refitted without any new holes.
Repeat as required.

The rails fix to the brackets and the panels to the rails.

You can't 'remove' individual tiles (and even more so slates) if the roof
has been properly nailed. A good slate roof is as tight as my
brother-in-law. No, sorry, I'm exaggerating. But it really is tight.
Believe me, I've been trying to find ways to route cables through roofs
for the last 40 years. If you start lifting individual tiles and slates
(even if you can, which on a well-nailed roof you won't be able to) you'll
never get the roof back to as good as it was before.
What happens if you try to force the issue with a nailed roof? Well you
will break a lot of tiles or slates.
If you do manage to slide a hanger bracket under a tile you won't be able
to nail it, and it's no good saying you'll go in the loft to do it because
of the roofing felt. So the only thing stabilising the hanger is the
weight of the tile. Wind gets under tiles and lifts them, and I've no
doubt it will get under solar panels. Constant movement is the enemy of a
sound roof.
On roofs with a gentle pitch there's always the danger of rain blowing up
under the slates, or getting sucked though due to pressure differentials.
Seen this many a time. Even a slim hanger bracket will make this much more
likely.
I've seen a lot of solar installations fixed by drilling holes through the
slates above the rafters and inserting a long bolt-thing with a screw tip.
Waterproofing is by a tight-fitting rubber grommet. It's obvious that this
arrangement is going to fail long before the panels are worn out.
When you stand on the ground and look up at panels they look OK. But climb
up there and get hold of them and you'll often find they're quite loose,
and can be lifted up with ease, bringing tiles with them.
The solar panel job, like the aerial job, is difficult for the customer to
have a close look at, so bad work is rife.

It will end in tears believe me. Give it a few years and the **** will hit
the fan.

Bill

You are exactly right Bill.
I have a (fake) slate roof and had that experience.
(My installation was an early days one)

Slates have to be removed with a ripper, the brackets fitted and lead
flashing put on.

There is at least one other person here has holes drilled.
This was done initially on mine but I was very suspicious & checked next
time we had heavy rain.
There were several slight drips you might easily miss. It could only get
worse and any leak can cause rot.

So Imade them come back and remove the lot and fix properly.

However the brackest they use on interlocking tiles are pretty well
foolproof,
I don't see there being a problem with those.

Bill Wright wrote:

A warning to aerial installers! My son Paul removed an old aerial from
the chimney and put it down on the roof, where it happened to touch the
frame of a solar panel. When he picked it up he received a severe
electric shock and he was lucky he wasn’t thrown off the roof. Obviously
the solar installation wasn’t properly earthed. Needless to say he
warned the householder that his solar installation was faulty, which
didn’t please him at all. I suggest everyone working on roofs treats
solar panels as a lethal shock hazard until proven otherwise. The last
thing you want when working at heights is an electric shock.

In the early days of television every TV and radio aerial was assumed to
be ‘live’. Maybe we need to go back to those days and work in rubber
gloves.

Have a look at page 22 (14 of the .pdf), onwards in this
document.

"Photovoltaics in Buildings Guide to the installation of PV
systems 2nd Edition"

http://www.bre.co.uk/filelibrary/pdf/rpts/Guide_to_the_installation_of_PV_systems_2nd_Editio n.pdf

There is a decision chart which I am not going to reproduce, but
the key details for average installs are

"...it is the electrical separation of the mains from the d.c.
using an isolating transformer that is the key determining factor
when assessing the requirement for array frame earthing."

"..freestanding ground mounted, or building roof mounted arrays
(away from building metalwork) will normally not be within the
equipotential zone."

"Where the incoming supply is PME (the majority of domestic
supply arrangements), the PME earth cannot be taken outside the
equipotential zone. This is to prevent the potential shock hazard
should the supply neutral ever be lost."

" [if no isolating transformer] Install & bond to earth spike
(Note: do not take PME out of equipotential Zone) (Note: Use 10
mm2 braid or equiv) "

further, on page 39 (22 of the .pdf)

"3.3.4 Shock hazard (safe working practices)
It is important to note that, despite all the above precautions,
an installer or service engineer may still encounter an electric
shock hazard:

Always test for the presence of voltage of parts before touching
any part of the system.
Where a residual electric shock hazard is encountered, live
working practices must be adopted (see above).

An electric shock may be experienced from a capacitive discharge
– a charge may build up in the PV system due to its distributed
capacitance to ground. Such effects are more prevalent in certain
types of modules and systems, namely amorphous (thin film)
modules with metal frames or steel backing. In such
circumstances, appropriate and safe live working practices must
be adopted.

An example of where such hazards may be encountered is the case
where an installer is seated on earthed metal roof wiring a large
PV array. In such circumstances the installer must touch the PV
cabling and can get an electric shock to earth. The electric
shock voltage will increase with the number of series connected
modules. The use of insulated tools and gloves, together with
insulating matting to stand or sit on, can mitigate this hazard.

An electric shock may also be experienced due to the PV array
developing a ground leakage path. Good wiring practice, double
insulation and modules of Class II construction can significantly
reduce this problem, but in any installed systems, leakage paths
may still occur. Any person working on a PV system must be aware
of this and take the necessary precautions."

Chris
--
Chris J Dixon Nottingham UK


Plant amazing Acers.

"Chris Hogg" wrote in message
...
On Wed, 03 Jul 2013 15:18:37 +0100, Bill Wright
wrote:

A warning to aerial installers! My son Paul removed an old aerial from
the chimney and put it down on the roof, where it happened to touch the
frame of a solar panel. When he picked it up he received a severe
electric shock and he was lucky he wasn't thrown off the roof. Obviously
the solar installation wasn't properly earthed. Needless to say he
warned the householder that his solar installation was faulty, which
didn't please him at all. I suggest everyone working on roofs treats
solar panels as a lethal shock hazard until proven otherwise. The last
thing you want when working at heights is an electric shock.

In the early days of television every TV and radio aerial was assumed to
be 'live'. Maybe we need to go back to those days and work in rubber
gloves.

It was quite serious. Paul said the shock felt like 240V 50Hz, so it's
likely the whole installation wasn't earthed. The high voltage from the
panels is DC of course, but Paul said he definitely felt the 50Hz! I
asked how many Hz he counted before he let go but he said he wasn't sure!

Of course the solar industry is full of bloody cowboys, so it's no
surprise. Some of the roof fixings they've used (that we've seen) are
terrible. There's going to be a legacy of leaking roofs in a few years.
That'll extend the payback time to infinity I should think!

Bill
Harks back to the thread a couple of weeks ago about the fire crew who
weren't allowed to tackle a fire in a building that had SPs on the
roof. In view of the above, you can see why.


Chris


Ah, yes. I've been meaning to get back to the group on this one. A friend of
mine is a retained fire fighter, and he has just qualified as a crew manager
(that used to be a leading hand, I think). Anyway, I asked him what the
policy was regarding a fire in a house with solar panels on the roof. He
says that as the crew manager, it is his responsibility to ensure the safety
of his crew, and the first thing that he has to do on arrival at the scene,
is to carry out a risk assessment. Part of that is to ensure that the power
to the premises is off. This, he says, is usually as a result of killing the
main input fuse to the house, and this is normally to be found either in the
hallway or garage of domestic premises.

In the case of there being solar panels on the roof, he says that there will
be a bloody great inverter in the system somewhere, and this is often
located in the roofspace where you can't see it or get at it. He accepts
that there are safety systems in place which should result in the inverter
being killed if the mains goes out (or is taken out), but he says that
because you can't immediately get at the inverter to check that it is dead,
it has to be assumed that the protection systems could be faulty or
compromised as a result of the fire, which could mean that the inverter is
actually still operating and back-feeding the house. As a result of this,
the current advice is not to go in without the direction and approval of a
senior officer who can make the assessment that it is safe for the crews to
start spraying water around.

So there we have it. This was as of a few weeks ago, and the situation might
be fluid and have changed again by now, or I suppose that it may vary
between brigades, but that is certainly the reason that the house that
started the discussion, burnt down ...

Arfa

"Arfa Daily" wrote in message
...


"Chris Hogg" wrote in message
...
On Wed, 03 Jul 2013 15:18:37 +0100, Bill Wright
wrote:

A warning to aerial installers! My son Paul removed an old aerial from
the chimney and put it down on the roof, where it happened to touch the
frame of a solar panel. When he picked it up he received a severe
electric shock and he was lucky he wasn't thrown off the roof. Obviously
the solar installation wasn't properly earthed. Needless to say he
warned the householder that his solar installation was faulty, which
didn't please him at all. I suggest everyone working on roofs treats
solar panels as a lethal shock hazard until proven otherwise. The last
thing you want when working at heights is an electric shock.

In the early days of television every TV and radio aerial was assumed to
be 'live'. Maybe we need to go back to those days and work in rubber
gloves.

It was quite serious. Paul said the shock felt like 240V 50Hz, so it's
likely the whole installation wasn't earthed. The high voltage from the
panels is DC of course, but Paul said he definitely felt the 50Hz! I
asked how many Hz he counted before he let go but he said he wasn't sure!

Of course the solar industry is full of bloody cowboys, so it's no
surprise. Some of the roof fixings they've used (that we've seen) are
terrible. There's going to be a legacy of leaking roofs in a few years.
That'll extend the payback time to infinity I should think!

Bill
Harks back to the thread a couple of weeks ago about the fire crew who
weren't allowed to tackle a fire in a building that had SPs on the
roof. In view of the above, you can see why.


Chris


Ah, yes. I've been meaning to get back to the group on this one. A friend
of mine is a retained fire fighter, and he has just qualified as a crew
manager (that used to be a leading hand, I think). Anyway, I asked him
what the policy was regarding a fire in a house with solar panels on the
roof. He says that as the crew manager, it is his responsibility to ensure
the safety of his crew, and the first thing that he has to do on arrival
at the scene, is to carry out a risk assessment. Part of that is to ensure
that the power to the premises is off. This, he says, is usually as a
result of killing the main input fuse to the house, and this is normally
to be found either in the hallway or garage of domestic premises.

In the case of there being solar panels on the roof, he says that there
will be a bloody great inverter in the system somewhere, and this is often
located in the roofspace where you can't see it or get at it. He accepts
that there are safety systems in place which should result in the inverter
being killed if the mains goes out (or is taken out), but he says that
because you can't immediately get at the inverter to check that it is
dead, it has to be assumed that the protection systems could be faulty or
compromised as a result of the fire, which could mean that the inverter is
actually still operating and back-feeding the house. As a result of this,
the current advice is not to go in without the direction and approval of a
senior officer who can make the assessment that it is safe for the crews
to start spraying water around.

So there we have it. This was as of a few weeks ago, and the situation
might be fluid and have changed again by now, or I suppose that it may
vary between brigades, but that is certainly the reason that the house
that started the discussion, burnt down ...

Arfa


Arfa, The facts are these.
The Pv panels produce electricity when the sun shines on them.
This can only be stopped by covering them up. (Not very practical)

If the mains power goes off for any reason the inverter shuts down/isolates
it'self
The PV is still active. And all the DC wires to the inverter. Up to
1000volts depending on how many panels, the inverter voltage and how it's
wired

On 04/07/2013 07:37, harryagain wrote:
....
Arfa, The facts are these.
The Pv panels produce electricity when the sun shines on them.
This can only be stopped by covering them up. (Not very practical)

If the mains power goes off for any reason the inverter shuts down/isolates
it'self...

What you mean is it should shut down, assuming it is not faulty and has
not been damaged by the fire. The Fire Brigade cannot assume that and
have to work on the principle that the house may still have live mains
inside.

Colin Bignell

Nightjar wrote:
On 04/07/2013 07:37, harryagain wrote:
...
Arfa, The facts are these.
The Pv panels produce electricity when the sun shines on them.
This can only be stopped by covering them up. (Not very practical)

If the mains power goes off for any reason the inverter shuts down/isolates
it'self...

What you mean is it should shut down, assuming it is not faulty and has
not been damaged by the fire. The Fire Brigade cannot assume that and
have to work on the principle that the house may still have live mains inside.

They also have to assume that even if the system is shut down that there
will be lethal voltage at roof level.

--
€¢DarWin|
_/ _/

On 04/07/2013 08:34, Steve Firth wrote:
Nightjar wrote:
On 04/07/2013 07:37, harryagain wrote:
...
Arfa, The facts are these.
The Pv panels produce electricity when the sun shines on them.
This can only be stopped by covering them up. (Not very practical)

If the mains power goes off for any reason the inverter shuts down/isolates
it'self...

What you mean is it should shut down, assuming it is not faulty and has
not been damaged by the fire. The Fire Brigade cannot assume that and
have to work on the principle that the house may still have live mains inside.

They also have to assume that even if the system is shut down that there
will be lethal voltage at roof level.


AIUI, the main concern is cables inside the house that may be exposed by
the fire and that fire fighters may come into contact with if they enter
the building.

Colin Bignell

On Thu, 04 Jul 2013 08:31:07 +0100, Nightjar
wrote:

What you mean is it should shut down, assuming it is not faulty and has
not been damaged by the fire. The Fire Brigade cannot assume that and
have to work on the principle that the house may still have live mains
inside.

AFAIK, here, the minimum distance for a spray (not stream) of water to be safely
directed at an electrical installation carrying up to 1000 Volts is one meter.
So I think live mains is not much of a problem, as far as spraying water goes.

Compare that to the dangers of a electric hybrid vehicle in the garage, with a
battery storing a significant amount of energy, using lithium which can do odd
things in a fire with water added. Or propane/butane tanks, properly or
improperly stored, the nasty by-products of burning PVC, a full cistern sitting
on rafters that are burning, and PV panels are just one more thing in a long
list of caveats.


Thomas Prufer

On 04/07/2013 10:40, Thomas Prufer wrote:
On Thu, 04 Jul 2013 08:31:07 +0100, Nightjar
wrote:

What you mean is it should shut down, assuming it is not faulty and has
not been damaged by the fire. The Fire Brigade cannot assume that and
have to work on the principle that the house may still have live mains
inside.

AFAIK, here, the minimum distance for a spray (not stream) of water to be safely
directed at an electrical installation carrying up to 1000 Volts is one meter.
So I think live mains is not much of a problem, as far as spraying water goes....

As I said in another reply, AIUI, the problem is firemen inside the
building walking into exposed live cables, or breaking into them when
cutting into walls or ceilings when trying to reach the seat of a fire.

Colin Bignell

"Nightjar" wrote in message
...
On 04/07/2013 07:37, harryagain wrote:
...
Arfa, The facts are these.
The Pv panels produce electricity when the sun shines on them.
This can only be stopped by covering them up. (Not very practical)

If the mains power goes off for any reason the inverter shuts
down/isolates
it'self...

What you mean is it should shut down, assuming it is not faulty and has
not been damaged by the fire. The Fire Brigade cannot assume that and have
to work on the principle that the house may still have live mains inside.

Colin Bignell

The inverter can't work without mains power any more than an electric motor
can.

There are AC and DC isolators adjacent to the inverter

But the DC is always there on the panels in sunlight.

harryagain wrote:

The inverter can't work without mains power any more than an electric motor
can.
My windscreen wipers work OK on 12V DC.

Bill

On 04/07/2013 18:31, harryagain wrote:
"Nightjar" wrote in message
...
On 04/07/2013 07:37, harryagain wrote:
...
Arfa, The facts are these.
The Pv panels produce electricity when the sun shines on them.
This can only be stopped by covering them up. (Not very practical)

If the mains power goes off for any reason the inverter shuts
down/isolates
it'self...

What you mean is it should shut down, assuming it is not faulty and has
not been damaged by the fire. The Fire Brigade cannot assume that and have
to work on the principle that the house may still have live mains inside.

Colin Bignell

The inverter can't work without mains power any more than an electric motor
can...

I would want to see a full failure mode and effects analysis before
making such definitive statements myself.

Colin Bignell

On 04/07/2013 18:31, harryagain wrote:
"Nightjar" wrote in message
...
On 04/07/2013 07:37, harryagain wrote:
...
Arfa, The facts are these.
The Pv panels produce electricity when the sun shines on them.
This can only be stopped by covering them up. (Not very practical)

If the mains power goes off for any reason the inverter shuts
down/isolates
it'self...

What you mean is it should shut down, assuming it is not faulty and has
not been damaged by the fire. The Fire Brigade cannot assume that and have
to work on the principle that the house may still have live mains inside.

Colin Bignell

The inverter can't work without mains power any more than an electric motor
can.

A motor needs mains power to actually drive it. The motive power on an
inverter is coming from the DC side. All the AC side needs to do is
provide synchronisation.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

So there we have it. This was as of a few weeks ago, and the situation
might be fluid and have changed again by now, or I suppose that it may
vary between brigades, but that is certainly the reason that the house
that started the discussion, burnt down ...

Arfa


Arfa, The facts are these.
The Pv panels produce electricity when the sun shines on them.
This can only be stopped by covering them up. (Not very practical)



If the mains power goes off for any reason the inverter shuts down/isolates
it'self
The PV is still active. And all the DC wires to the inverter. Up to
1000volts depending on how many panels, the inverter voltage and how it's
wired




Harry that assumption is rather shall.. we say suspect?. So here we have
a possible potential of several hundred volts DC which may, or may not
be connected to anything or everything.

That potential and where it rises and what its across is unlike the
mains incomer it's a very suspect power source. We can only assume that
its going to behave the way it should. The problem is that the power
source is up there on the roof with cables coming down into the building
and even if the inverter does shut down or go tits up whatever, there is
still that power "source" up there and thats the real problem. In a fire
situation theres no way of knowing where it is or what its doing or
where its connected to or to what its connected either.

It may well be safe it may well do what its supposed to do but its
analogous to having say large structures all over the roof and a cable
coming from next door and connected to that wherever you wish and under
fire conditions what has melted thru, what has accidentally connected to
whatever?...

The more you think about it the more awkward this one gets for the
safety of anyone up there on the roof, or squirting water up there.

Perhaps we shall see apparatus like what they use on high voltage power
line working where they bond the cables together and put a big earthing
stake in!..


--
Tony Sayer

"tony sayer" wrote in message
...
So there we have it. This was as of a few weeks ago, and the situation
might be fluid and have changed again by now, or I suppose that it may
vary between brigades, but that is certainly the reason that the house
that started the discussion, burnt down ...

Arfa


Arfa, The facts are these.
The Pv panels produce electricity when the sun shines on them.
This can only be stopped by covering them up. (Not very practical)



If the mains power goes off for any reason the inverter shuts
down/isolates
it'self
The PV is still active. And all the DC wires to the inverter. Up to
1000volts depending on how many panels, the inverter voltage and how it's
wired




Harry that assumption is rather shall.. we say suspect?. So here we have
a possible potential of several hundred volts DC which may, or may not
be connected to anything or everything.

That potential and where it rises and what its across is unlike the
mains incomer it's a very suspect power source. We can only assume that
its going to behave the way it should. The problem is that the power
source is up there on the roof with cables coming down into the building
and even if the inverter does shut down or go tits up whatever, there is
still that power "source" up there and thats the real problem. In a fire
situation theres no way of knowing where it is or what its doing or
where its connected to or to what its connected either.

It may well be safe it may well do what its supposed to do but its
analogous to having say large structures all over the roof and a cable
coming from next door and connected to that wherever you wish and under
fire conditions what has melted thru, what has accidentally connected to
whatever?...

The more you think about it the more awkward this one gets for the
safety of anyone up there on the roof, or squirting water up there.

Perhaps we shall see apparatus like what they use on high voltage power
line working where they bond the cables together and put a big earthing
stake in!..


Well that wouldn't work, HV is de-energised before it is earthed before
working on.

The point is that you can't stop the panels from functioning in daylight
(other than covering them up.)_

Maybe they could have a spray paint device.

The more you think about it the more awkward this one gets for the
safety of anyone up there on the roof, or squirting water up there.

Perhaps we shall see apparatus like what they use on high voltage power
line working where they bond the cables together and put a big earthing
stake in!..


Well that wouldn't work, HV is de-energised before it is earthed before
working on.

The point is that you can't stop the panels from functioning in daylight
(other than covering them up.)_

Maybe they could have a spray paint device.



Or tinfoil hats...
--
Tony Sayer

On Thu, 4 Jul 2013 09:37:04 +0100, tony sayer
wrote:

Perhaps we shall see apparatus like what they use on high voltage power
line working where they bond the cables together and put a big earthing
stake in!..

They wash insulators and switchgear live, with water, from just a few
metres away.

Not 240v stuff though. Grid system voltages and *very* pure water.

On 05/07/2013 16:55, The Other Mike wrote:
On Thu, 4 Jul 2013 09:37:04 +0100, tony sayer
wrote:

Perhaps we shall see apparatus like what they use on high voltage power
line working where they bond the cables together and put a big earthing
stake in!..

They wash insulators and switchgear live, with water, from just a few
metres away.

Not 240v stuff though. Grid system voltages and *very* pure water.


Don't know if this applies to fire hoses, but when I worked in the
pressure washer game I saw some high speed photos of a pressure jet
spray. It wasn't a single stream of water, but lots of small droplets
separate from each other.


--
Dave - The Medway Handyman www.medwayhandyman.co.uk

"harryagain" writes:


"Arfa Daily" wrote in message
...


"Chris Hogg" wrote in message
...
On Wed, 03 Jul 2013 15:18:37 +0100, Bill Wright
wrote:

A warning to aerial installers! My son Paul removed an old aerial from
the chimney and put it down on the roof, where it happened to touch the
frame of a solar panel. When he picked it up he received a severe
electric shock and he was lucky he wasn't thrown off the roof. Obviously
the solar installation wasn't properly earthed. Needless to say he
warned the householder that his solar installation was faulty, which
didn't please him at all. I suggest everyone working on roofs treats
solar panels as a lethal shock hazard until proven otherwise. The last
thing you want when working at heights is an electric shock.

In the early days of television every TV and radio aerial was assumed to
be 'live'. Maybe we need to go back to those days and work in rubber
gloves.

It was quite serious. Paul said the shock felt like 240V 50Hz, so it's
likely the whole installation wasn't earthed. The high voltage from the
panels is DC of course, but Paul said he definitely felt the 50Hz! I
asked how many Hz he counted before he let go but he said he wasn't sure!

Of course the solar industry is full of bloody cowboys, so it's no
surprise. Some of the roof fixings they've used (that we've seen) are
terrible. There's going to be a legacy of leaking roofs in a few years.
That'll extend the payback time to infinity I should think!

Bill
Harks back to the thread a couple of weeks ago about the fire crew who
weren't allowed to tackle a fire in a building that had SPs on the
roof. In view of the above, you can see why.


Chris


Ah, yes. I've been meaning to get back to the group on this one. A friend
of mine is a retained fire fighter, and he has just qualified as a crew
manager (that used to be a leading hand, I think). Anyway, I asked him
what the policy was regarding a fire in a house with solar panels on the
roof. He says that as the crew manager, it is his responsibility to ensure
the safety of his crew, and the first thing that he has to do on arrival
at the scene, is to carry out a risk assessment. Part of that is to ensure
that the power to the premises is off. This, he says, is usually as a
result of killing the main input fuse to the house, and this is normally
to be found either in the hallway or garage of domestic premises.

In the case of there being solar panels on the roof, he says that there
will be a bloody great inverter in the system somewhere, and this is often
located in the roofspace where you can't see it or get at it. He accepts
that there are safety systems in place which should result in the inverter
being killed if the mains goes out (or is taken out), but he says that
because you can't immediately get at the inverter to check that it is
dead, it has to be assumed that the protection systems could be faulty or
compromised as a result of the fire, which could mean that the inverter is
actually still operating and back-feeding the house. As a result of this,
the current advice is not to go in without the direction and approval of a
senior officer who can make the assessment that it is safe for the crews
to start spraying water around.

So there we have it. This was as of a few weeks ago, and the situation
might be fluid and have changed again by now, or I suppose that it may
vary between brigades, but that is certainly the reason that the house
that started the discussion, burnt down ...

Arfa


Arfa, The facts are these.
The Pv panels produce electricity when the sun shines on them.
This can only be stopped by covering them up. (Not very practical)

Spray dark mud on them?

If the mains power goes off for any reason the inverter shuts down/isolates
it'self
The PV is still active. And all the DC wires to the inverter. Up to
1000volts depending on how many panels, the inverter voltage and how it's
wired

Maybe they need a ground-level crowbar switch to short them out in an
emergency?


--
Windmill, Use t m i l l
J.R.R. Tolkien:- @ S c o t s h o m e . c o m
All that is gold does not glister / Not all who wander are lost

Arfa Daily wrote:

Ah, yes. I've been meaning to get back to the group on this one. A friend
of mine is a retained fire fighter, and he has just qualified as a crew
manager (that used to be a leading hand, I think). Anyway, I asked him
what the policy was regarding a fire in a house with solar panels on the
roof. He says that as the crew manager, it is his responsibility to ensure
the safety of his crew, and the first thing that he has to do on arrival
at the scene, is to carry out a risk assessment. Part of that is to ensure
that the power to the premises is off. This, he says, is usually as a
result of killing the main input fuse to the house, and this is normally
to be found either in the hallway or garage of domestic premises.

Now that's making me wonder what would be the situation with our bungalow.
We don't have solar panels but the meter and CU are in the eaves space
because the supply was originally via overhead cables. At some time in the
distant past it was changed to an underground supply with a cable running up
the outside of the house into the roof. There's no way a firefighter could
get to this without going right through the burning house, assuming that he
even knew where it was. The thick cable running up the wall would give a
clue but for most of the year it's well hidden behind the dense foliage of a
wisteria which grows up the wall.

--
Mike Clarke

"Mike Clarke" wrote in message
...
Arfa Daily wrote:

Ah, yes. I've been meaning to get back to the group on this one. A friend
of mine is a retained fire fighter, and he has just qualified as a crew
manager (that used to be a leading hand, I think). Anyway, I asked him
what the policy was regarding a fire in a house with solar panels on the
roof. He says that as the crew manager, it is his responsibility to
ensure
the safety of his crew, and the first thing that he has to do on arrival
at the scene, is to carry out a risk assessment. Part of that is to
ensure
that the power to the premises is off. This, he says, is usually as a
result of killing the main input fuse to the house, and this is normally
to be found either in the hallway or garage of domestic premises.

Now that's making me wonder what would be the situation with our bungalow.
We don't have solar panels but the meter and CU are in the eaves space
because the supply was originally via overhead cables. At some time in the
distant past it was changed to an underground supply with a cable running
up
the outside of the house into the roof. There's no way a firefighter could
get to this without going right through the burning house, assuming that
he
even knew where it was. The thick cable running up the wall would give a
clue but for most of the year it's well hidden behind the dense foliage of
a
wisteria which grows up the wall.

--
Mike Clarke


I will see my fire fighter chum tomorrow, Mike. If I remember, I'll ask him
for you ...

Arfa

On Thursday, July 4, 2013 9:38:07 AM UTC+1, Mike Clarke wrote:
Arfa Daily wrote:

Ah, yes. I've been meaning to get back to the group on this one. A friend
of mine is a retained fire fighter, and he has just qualified as a crew
manager (that used to be a leading hand, I think). Anyway, I asked him
what the policy was regarding a fire in a house with solar panels on the
roof. He says that as the crew manager, it is his responsibility to ensure
the safety of his crew, and the first thing that he has to do on arrival
at the scene, is to carry out a risk assessment. Part of that is to ensure
that the power to the premises is off. This, he says, is usually as a
result of killing the main input fuse to the house, and this is normally
to be found either in the hallway or garage of domestic premises.



Now that's making me wonder what would be the situation with our bungalow..
We don't have solar panels but the meter and CU are in the eaves space
because the supply was originally via overhead cables. At some time in the
distant past it was changed to an underground supply with a cable running up
the outside of the house into the roof. There's no way a firefighter could
get to this without going right through the burning house, assuming that he
even knew where it was. The thick cable running up the wall would give a
clue but for most of the year it's well hidden behind the dense foliage of a
wisteria which grows up the wall.

There must be many houses like mine (most of the ones in my street, for example) where the electricity supply comes in from an underground cable directly into the cellar. To get to it you have to go down stairs at the back of the main part of the house, then from the bottom of the stairs all the way to the far corner of the cellar. Gas comes in there, too...
House next door had a fire some years back, and the fire brigade got it under control quite quickly, so they must have some procedure worked out.

On 04/07/2013 12:08, wrote:

There must be many houses like mine (most of the ones in my street, for example)
where the electricity supply comes in from an underground cable
directly into the cellar.
To get to it you have to go down stairs at the back of the main part of the house,
then from the bottom of the stairs all the way to the far corner of
the cellar.
Gas comes in there, too...
House next door had a fire some years back, and the fire brigade got it under control
quite quickly, so they must have some procedure worked out.


You say "some years back" - might that have been before the days of
needing a risk assessment to even put their wellies on?


--
Chris

"Mike Clarke" wrote in message
...
Arfa Daily wrote:

Ah, yes. I've been meaning to get back to the group on this one. A friend
of mine is a retained fire fighter, and he has just qualified as a crew
manager (that used to be a leading hand, I think). Anyway, I asked him
what the policy was regarding a fire in a house with solar panels on the
roof. He says that as the crew manager, it is his responsibility to
ensure
the safety of his crew, and the first thing that he has to do on arrival
at the scene, is to carry out a risk assessment. Part of that is to
ensure
that the power to the premises is off. This, he says, is usually as a
result of killing the main input fuse to the house, and this is normally
to be found either in the hallway or garage of domestic premises.

Now that's making me wonder what would be the situation with our bungalow.
We don't have solar panels but the meter and CU are in the eaves space
because the supply was originally via overhead cables. At some time in the
distant past it was changed to an underground supply with a cable running
up
the outside of the house into the roof. There's no way a firefighter could
get to this without going right through the burning house, assuming that
he
even knew where it was. The thick cable running up the wall would give a
clue but for most of the year it's well hidden behind the dense foliage of
a
wisteria which grows up the wall.

--
Mike Clarke


OK. Saw my firefighter chum today, and asked him what the situation is in a
case like yours where the location of the company fuse is not obvious. When
asked, he added to that scenario by saying that even when the location of
the CU / company fuse *is* known, it's not always possible to get to it, as
the fire might be raging away in your way. He says that in these cases, it
comes down to the judgment of the crewman doing the evaluation, and that in
most cases, he will send the guys in with a warning that the premises have
not been isolated, and this fact will be noted on the risk assessment sheet.
Apparently, what will then normally happen in these cases, is that pretty
soon after they start spraying water around, MCBs in the house will start to
pop, effectively providing an acceptable level of isolation. In the event
that these are damaged and don't pop, he says that the company fuse will
usually blow. Also, he says that it is not at all uncommon for one of the
big two-handed fuses down the road in the substation to pop, putting out
half of the street ...

So, again, it looks like there is a degree of common sense involved on the
part of the fire officers, which leaves it all a bit in the air, really ...

Arfa

So, again, it looks like there is a degree of common sense involved on the
part of the fire officers, which leaves it all a bit in the air, really ...

Arfa


Interesting .. but did you ask him as to what advice, if any, they were
given in Solar panel equipped houses?...

--
Tony Sayer

"tony sayer" wrote in message
...

So, again, it looks like there is a degree of common sense involved on the
part of the fire officers, which leaves it all a bit in the air, really
...

Arfa


Interesting .. but did you ask him as to what advice, if any, they were
given in Solar panel equipped houses?...

--
Tony Sayer



Yes, I detailed that further up the thread. The last advice that he had was
to await authorisation from a senior officer

Arfa

On Thu, 4 Jul 2013 02:01:47 +0100, Arfa Daily wrote:

Anyway, I asked him what the policy was regarding a fire in a house with
solar panels on the roof. He says that as the crew manager, it is his
responsibility to ensure the safety of his crew, and the first thing
that he has to do on arrival at the scene, is to carry out a risk
assessment. Part of that is to ensure that the power to the premises is
off. This, he says, is usually as a result of killing the main input
fuse to the house, and this is normally to be found either in the
hallway or garage of domestic premises.

Hum, in our case there are several CU's dotted about the place, or do
you really mean that they find and pull the main cut out? The
location of that is not immedately obvious here but could probably be
worked out by where the overhead feed runs.

The local ambulance service have a database of actual location and
directions to homes so they can find them quickly. In rural areas the
post code isn't good enough and the caller may not know it... The
information being provided by the home owners. I wonder if the fire
service also have such a database, location of the property(*) and
location/access to things like mains cut outs?

In the case of there being solar panels on the roof, he says that there
will be a bloody great inverter in the system somewhere, and this is
often located in the roofspace where you can't see it or get at it. He
accepts that there are safety systems in place which should result in
the inverter being killed if the mains goes out (or is taken out), but
he says that because you can't immediately get at the inverter to check
that it is dead, it has to be assumed that the protection systems could
be faulty or compromised as a result of the fire, which could mean that
the inverter is actually still operating and back-feeding the house. As
a result of this, the current advice is not to go in without the
direction and approval of a senior officer who can make the assessment
that it is safe for the crews to start spraying water around.

Seems wise, as far as entry in concerned. But it doesn't stop 'em
standing back, breaking windows and squirting loads of water in,
won't stop the fire but may contain it.

I wonder what the insurance companies are making of this?

... I suppose that it may vary between brigades, ...

And possibly where you live. Fire cover here is a single pump with
retained crew, they can probably get to most most homes around here
in 10 to 15 minutes from the brigade receiving the call. If the place
has solar PV and they don't enter until a senior officer has arrived
(at least 30 to 40 mins) and given the OK, the place will be
effectively burnt down.

Having said that in 10-15 minuets the place will be well alight
anyway as a couple did more or less burn down in the last few years
and that was without solar PV slowing down entry.

(*) The fire service will most likely have a bit of a give away from
the great column of smoke from the fire, the ambulance may well not
have that.

--
Cheers
Dave.

On 04/07/2013 10:08, Dave Liquorice wrote:
On Thu, 4 Jul 2013 02:01:47 +0100, Arfa Daily wrote:

Anyway, I asked him what the policy was regarding a fire in a house with
solar panels on the roof. He says that as the crew manager, it is his
responsibility to ensure the safety of his crew, and the first thing
that he has to do on arrival at the scene, is to carry out a risk
assessment. Part of that is to ensure that the power to the premises is
off. This, he says, is usually as a result of killing the main input
fuse to the house, and this is normally to be found either in the
hallway or garage of domestic premises.

Hum, in our case there are several CU's dotted about the place, or do
you really mean that they find and pull the main cut out? The
location of that is not immedately obvious here but could probably be
worked out by where the overhead feed runs.

The local ambulance service have a database of actual location and
directions to homes so they can find them quickly. In rural areas the
post code isn't good enough and the caller may not know it... The
information being provided by the home owners. I wonder if the fire
service also have such a database, location of the property(*) and
location/access to things like mains cut outs?

London Ambulance use a system called FREDA (Fast Response Electronic
Dispatch of Ambulances). As soon as control has the address, the info
is sent to a data terminal in the ambulance, the system sets the
ambulance's sat nav - and its position is fed back to control.

Very often the crew get the address before they get the details of the
job. They also get updated by control on the way.

The system has a database of historic incidents by postcode, so in some
areas the data terminal will flash up 'stab vest mandatory' or 'do not
leave ambulance until Police are on scene'.

On Cat A calls, control stay on the phone to the caller, they can tell
them where the ambo is and when the ambo gets to the street, control
tell to caller to send someone outside to wave (if possible).



--
Dave - The Medway Handyman www.medwayhandyman.co.uk

On Thursday 04 July 2013 19:17 The Medway Handyman wrote in uk.d-i-y:


The system has a database of historic incidents by postcode, so in some
areas the data terminal will flash up 'stab vest mandatory' or 'do not
leave ambulance until Police are on scene'.

Christ, it's a **** world...

On Cat A calls, control stay on the phone to the caller, they can tell
them where the ambo is and when the ambo gets to the street, control
tell to caller to send someone outside to wave (if possible).



--
Tim Watts Personal Blog: http://squiddy.blog.dionic.net/

http://www.sensorly.com/ Crowd mapping of 2G/3G/4G mobile signal coverage

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On Thu, 04 Jul 2013 21:44:07 +0100, Tim Watts wrote:

The system has a database of historic incidents by postcode, so in
some
areas the data terminal will flash up 'stab vest mandatory' or 'do
not
leave ambulance until Police are on scene'.

Christ, it's a **** world...

THM's daughter works for the London Ambulance Service, London is a
**** place to live, no I'll rephrase that, a **** place to exist. So
are parts of many other big cities.

--
Cheers
Dave.