Catastophic failure on ITV
 

On Tue, 03 Jun 2008 10:20:45 +0100, Zathras wrote:

Rather than just a 'hefty load' I'd prefer it to run the *actual* load
during testing.

Being ultra cautious one would run the system into a decent dummy load
before switching across to the actual load. Sod has a unerring abilty to
strike when you are most vulnerable.

In a big environment, there's always kit that should and shouldn't be on
the generator supply.

You mean the odd extension lead and kettle... B-)

Why would it need to run 'for several hours'..I'd have thought that
one hour would have been more than satisfactory.

Depends how long it takes things to *fully* warm up. More of that slightly
loose connection or hidden damage from rodents or partialy obstructed by a
birds nest air duct than the engine and alternator.

No idea. I guess it's twin engine due to the load requirements.

I have a feeling that twin engines on the same shaft is not easy. If one
engine has slightly higher output than the other... Not saying it can't be
done but it adds to the control system and for this sort of thing KISS
rules.

--
Cheers
Dave.

Catastophic failure on ITV
 

On Tue, 03 Jun 2008 10:40:31 +0100, Zathras wrote:

Assuming VOIP phones *always work* appears to be an increasingly
common error.

Assuming that any of our modern technology always works is an increasingly
common error.

--
Cheers
Dave.

Catastophic failure on ITV
 

"Zathras" wrote in message
...
On Mon, 2 Jun 2008 10:26:55 +0100, "Mortimer" wrote:

there was
a loud bang from the generator, a blinding flash of blue and a huge sheet
or
orange flame: it transpired that the power being drawn was vastly in
excess
of what the generator was rated to supply and it had overloaded,

Hmmm..I'd have expected some kind of over-current protection on the
generator output. Sounds like a poorly maintained cowboy install?

Yes I was rather amazed that there wasn't an over-current device - either a
trip switch to cut the fuel to the diesel engine, a circuit breaker or even
a simple fuse.

I've experienced 100% VOIP failure when an errant device
on a very high bandwidth VLAN decided to produce a broadcast storm.
More entertainingly, our remote network management people hadn't a
clue because they couldn't connect to any network devices to find out
what the problem was!! BTW, I've summarised and there were specific
reasons why the LAN was deliberately not hardened for this kind of DOS
attack. Strangely, it's a little more hardened now!

When I was developing a product for restoring a PC's hard disk from an image
based on a server, over the LAN, one of my colleagues managed to bring the
company LAN to a grinding halt when he connected the server and PC onto the
company LAN instead of a private test LAN. The rate at which data was
transferred swamped the switch and left very little time for other traffic.
Luckily it only affected the segments supplied by that hub and didn't go
upstream to affect other floors in the building - the benefits of switches
rather than hubs! As a result, I managed to persuade Sysmantec to include a
"throttling" option into Ghost so that you could artificially restrict the
rate at which the server would supply data, so as to leave spare capacity
for other LAN traffic - important as the product was intended for use on a
live LAN once it was in the field.

One of the few disciplinary offences in the company was the connection of
any DHCP server to the LAN, on the grounds that it may supply either
duplicate addresses to the ones supplied by the real DHCP server or else
completely different addresses if the rogue server had a different
scope/subnet to the real one. When you have one hub on your desk that's on
the company LAN and another one that's on a private test LAN, you need to
make very certain which LAN you are connecting your server to!

Catastophic failure on ITV
 

"Zero Tolerance" wrote in message
...
On Sun, 1 Jun 2008 16:48:32 +0100, "Stephen"
wrote:

I thought that Freeview multiplexes 1, B, C, D were put together by
BBC/RedBee coding & multiplexing. ITV2+1 is on mux C or D (don't remember
which), so if it doesn't go there I wonder where it does go?

No, Mux C and D are operated by National Grid Wireless. Nothing to do
with the BBC or Red Bee in any way.

--

I worked for company in the early 70 s with a system UPS. Mains driving a
generater, on the same shaft a massive flywheel and clutch.On the other side
of the clutch a deisel engine. When the mains failed the clutch engaged and
the deisel engine took over.Apart from the noise, and the fright, if you
were in the building, the only thing that happend was a dip in the frequency
down to 48 cps.

There was also a fire prevention system which consisted of 4 large CO2
bottles . these discharged into the building in the event of fire.

Catastophic failure on ITV
 

"Andy Burns" wrote in message
et...
On 03/06/2008 17:14, Tonyatk wrote:

I worked for company in the early 70 s with a system UPS. Mains driving
a generater, on the same shaft a massive flywheel and clutch.On the other
side of the clutch a deisel engine. When the mains failed the clutch
engaged and the deisel engine took over. Apart from the noise, and the
fright, if you were in the building, the only thing that happend was a
dip in the frequency down to 48 cps.

There was also a fire prevention system which consisted of 4 large CO2
bottles. these discharged into the building in the event of fire.

I was waiting for the " ... until one day ... "

Fortunatly we were well trained. So that the first thing to do was to disarm
the co2 system as soon as we went in .In doing so a big flap came down so
the door could not be closed. So had to arm the system be fore we left to
close the door.

We once tested the co2 system by setting up a remote triggering device .
Being small room we stood some 20 yadrs away with the door open (Safty
system disabled.) WoW ! ! !

Catastophic failure on ITV
 

In ll.net,
Dave Liquorice typed, for some strange,
unexplained reason:
: On Tue, 03 Jun 2008 10:20:45 +0100, Zathras wrote:
:
: Rather than just a 'hefty load' I'd prefer it to run the *actual*
: load during testing.
:
: Being ultra cautious one would run the system into a decent dummy load
: before switching across to the actual load. Sod has a unerring abilty
: to strike when you are most vulnerable.
:
: In a big environment, there's always kit that should and shouldn't
: be on the generator supply.
:
: You mean the odd extension lead and kettle... B-)

When I worked for British Rail in the late 80's/early 90's at Stanier
House in Birmingham all our computer equipment was on a completely
separate mains supply which was stabilised and backed up by UPS's and a
generator. To stop people plugging kettles, etc. into the computer supply,
they fitted non-standard plugs & sockets with the pins rotated by 90
degrees ("Walsall" gauge, for those that know them) but it didn't take at
least one enterprising person to find a spare plug to put on their
kettle..!

Fortunately, I never knew the mains fail while I was there. Although the
number of people unplugging the T-base-2 Ethernet
connectors.................!

Ivor

Catastophic failure on ITV
 

Zero Tolerance wrote:
On Sun, 1 Jun 2008 16:48:32 +0100, "Stephen"
wrote:


I thought that Freeview multiplexes 1, B, C, D were put together by
BBC/RedBee coding & multiplexing. ITV2+1 is on mux C or D (don't remember
which), so if it doesn't go there I wonder where it does go?


No, Mux C and D are operated by National Grid Wireless. Nothing to do
with the BBC or Red Bee in any way.

IIRC the coding and Muxing is done by Siemens (ex BBC-Technology) at TV
Centre