Another one for your welcome input.... an intro to the backup power
options



There are lots of ways of providing '''Backup power'''. This article
introduces the various options, with their main features. Some of
these have their own articles that go into the option in more detail.


==Power options==
===Generator===
* how to detemine power needed
* noise
* maintenance
* cost
* service life (often very short)
* 2 strokes and starting reliability
* listeroids
* connecting to mains wiring

===Torch===

===Gas lighting===
Despite being historic technology, gas lighting has some advantages
over electrical power. The main one is its long term reliability,
which is hard to match using elecrical kit. Gas lights can be expected
to work for decades without attention or failure.

Gas cylinders don't discharge in storage, so power is always there
ready to go. This contrasts noticeably with rechargeable batteries,
which are prone to either
* being flat when wanted if not left on trickle charge
* having limited life if left on trickle

Gas lights produce a lot of heat due to low efficieny, and with
suitable care this can be used to cook or heat water. Even a small
camping gas light will put out around 400w of heat, which is enough to
cook on.

The high heat output means it should be put somewhere it cant be
knocked over in use. Hanging from the ceilng is often practical.

Putting foil round half the globe produces nearly twice the level of
forward light.

Cost per volume of gas varies widely for different cartridge types.
High gas cost lights can be uneconomic purchases, even if cheaper
initially.


===UPS===
'''U'''ninterruptible '''P'''ower '''S'''upplies provide a mains feed
that's not interrupted in the event of a power cut. The switchover to
internal battery is instant.

Large whole building units are available, but nearly all UPSes sold
are plug-in items intended to run one or a few low power appliances,
typically a computer system.

To avoid disappointment, the required capacity of UPS should be
calculated before purchase, otherwise its likely to fail to deliver
the run time wanted. UPS capacity is rated in kWh (kilowatts x hours),
so for example a 0.2kWh UPS could run a 100w (0.1kW) load for 2 hours.

UPSes are also rated by their max continuous power output. The load
appliance(s) should not exceed this rating. Note its the load's VA
that matters rather than watts. For some loads VA = watts, and for
some their VA rating is greater than watt rating.

Finally UPSes are also rated by peak power output. Some appliances
draw well above running power for a brief period at startup. It would
be wrong to assume that if the UPS meets an appliance's run current it
would also meet the startup current requirement.


===Laptop===
A laptop is often a practical way to get computer time during power
loss.

Where TV is wanted to sedate the kids, a laptop with a USB TV card can
be cheaper than a UPS to run the main TV, and of rather more use.

Extra batteries can give more run time. As well as expensive Li-ion
laptop batteries, laptops can be run off lead acids with higher
capacity and lower cost per hour, or carbon iron batteries.
Manufacturer's instructions should be followed in such cases.


===Lead acid, charger, invertor===
A good option for people that already have most or all of the parts.
However the necessary bits and leads need to all be to hand when the
power cut bhappens, and te battery must of course be charged and ready
to go.

===Candles===
Although basic, candles are a workable way to provide occasional
lighting. £1 buys a lot of tea lights.

Candles are associated with significant fire risk, so its only
sensible to use some means to keep the candle safe in use. Wall
sconces are effective, placing the candle high up out of reach,
especially of young kids.

Always keeping candles and matches in the same place makes finding
them in the dark easy.


===Emergency escape lights===
Non-maintained lights will light up automatically when mains power
fails. (Maintained units are designed for a slightly different job.)

Run time typically 1-3 hours, typical cost £15-20.

Fluorescent units generally give more run time due to the much higher
efficiency of fluorescent tubes.


===Rechargeable torch===
These are left permanently on trickle charge. Some can be set to come
on automatically when power goes off. Available light output and run
time vary.

Fluorescent torches generally give better run time, since the
fluorescent tube is much more energy efficient than the filament bulb.

All share one defect, limited battery life, and will require re-
celling after so many years. Cells with higher capacity can give
longer run time if required.


===Carbon iron battery===
The home made carbon iron battery can provide plenty of power at any
chosen voltage during a power cut. These are stored dry, and water is
added to activate them. Because of this, shelf life is indefinate.

Construction cost is trivial, they're easily replenished after use,
and can be built to any size for any load requirement.


===Luminaire backup pack===
Mains fluorescent lights are available with a battery backup pack
built in which will light the tube when mains fails. Be aware that
battery operation is usually at much reduced power. While popular in
commercial premises, this is not one of the cheaper options for
domestic use, expect to pay anywhere in the region of £80 or so. They
also arent generally styled for domestic use, but this issue is easily
sidestepped with trough installation.

===12v battery & 12v lights===
Fluorescent lights give several times the run time per light output
than filament lamps. A practical option where mains power isn't
needed.

Its possible to feed 12v wiring to every room, and add a relay that
switches a 12v lighting system on when mains fails. This may be an
attractive option when carrying out work that permits running new low
voltage wires, such as major redecoration, rewiring, installing a
wired network, etc.

Lead acid batteries require a few minutes of occasional maintenance to
last well.


===Nothing===
A lot of people choose no back up power, and are quite happy to sit in
quiet for once. It can be a nice break in a hectic life, and quite
refreshing.


==Choice==
The usual question that's posed when choosing is:

What do you want power for?
* lighting
* ch/hw
* tv
* computer
* etc

What will that cost, and is it worth it?

Now, more realistically, what will do?


==Business use==
When using backup power for commercial premises, its helpful to
estimate how much business is lost in one power cut, and roughly what
this value adds to over say a 10 year life of a power backup system.
This quick calculation shows that UPSes are a no-brainer for many
businesses.

Bear in mind that power cuts are in practice due to on-premises faults
as well as supply outages, and that getting an electrician generally
takes many hours.


==Connecting to house electrical circuits==
Care should be used in doing this, as its quite possible to kill or
injure a linesman if its not done right. Integrating the backup power
source with the whole house wiring is more involved than most DIYers
are willing to do. Running an extension lead from power to appliance
is a simpler option.


==See Also==
* [[Special:Allpages|Wiki Contents]]
* [[Special:Categories|Wiki Subject Categories]]



[[Category:Electrical]]


NT

On Wed, 30 Jul 2008 19:34:19 -0700 (PDT), wrote:

===Gas lighting===
Add that a small camping lantern will produce more light than a 60W
incandesent light bulb for several hours when flat out. If longer run time
or less light is required they can be turned down and give really long run
times, 10 hours or more depending on cartridge size. The quality of the
light is much better than electric as well.

To avoid disappointment, the required capacity of UPS should be
calculated before purchase, otherwise its likely to fail to deliver
the run time wanted. UPS capacity is rated in kWh (kilowatts x hours),
so for example a 0.2kWh UPS could run a 100w (0.1kW) load for 2 hours.

Not convinced that is correct. My APC Smart UPS 700 is rated at a nominal
700W, ie it will deliver 700W but the runtime at that power level is at
best 10 minutes.

Yes, I see that thar rating in the wiki is kWh but I've not seen that used
as the headline rating of a UPS.

UPSes are also rated by their max continuous power output. The load
appliance(s) should not exceed this rating. Note its the load's VA
that matters rather than watts. For some loads VA = watts, and for
some their VA rating is greater than watt rating.

Ah, I'd swap these to around as the VA is more often quoted along with a
runtime at various power levels rather than an overall kWh rating,
certainly for smaller UPS units. Large industrial ones may well have their
ratings quoted differently.

Finally UPSes are also rated by peak power output. Some appliances
draw well above running power for a brief period at startup. It would
be wrong to assume that if the UPS meets an appliance's run current it
would also meet the startup current requirement.

Add a warning that switching something on that takes a surge can trip the
UPS protection circuit when running on battery power. That same appliance
probably won't when the UPS is on mains power.

===Rechargeable torch===

Add "shaker" torches. These you shake for a 30s or so to provide light for
a few minutes. They work by having a magnet slide through a coil
generating electricity that is stored in a capacitor. The light source is
a white LED. The light is not winderful but enough to see by to find and
startup up other back up systems. With built in power generation and or
bulb to blow reliablity is high.

===Carbon iron battery===
The home made carbon iron battery

Interesting link to instructions?

--
Cheers
Dave.

Someone is very busy. Thanks for putting in the effort.

Suggestions:

Mention that the ADSL/cable modem and router(s) will need to be on the
UPS - not just the computer system.

Various forms of glow stick/light can be very effective. Although
relatively expensive, they are very safe and can be stored for long periods.

Simple glow-in-the-dark tabs/labels can help in locating door handles,
light switches, etc.

Although not ideal on the safety front, Coleman-style petrol stoves and
lamps are cheap to run on unleaded (or were until recently :-) ), and
very effective. My choice for one-ring emergency cooking outdoors.

For many, use of some sort of amplifier and/or distribution device is
necessary for their television reception. This too will need to be on
UPS if it is to work. And, of course, the various set-top boxes
(including the ridiculously hot running, power hungry Virgn media boxes).

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

On 31/07/2008 10:36, Rod wrote:

Mention that the ADSL/cable modem and router(s) will need to be on the
UPS - not just the computer system.

Useful to put DECT basestation on UPS too, but also keep a wired phone
handy.

Dave Liquorice wrote:

To avoid disappointment, the required capacity of UPS should be
calculated before purchase, otherwise its likely to fail to deliver
the run time wanted. UPS capacity is rated in kWh (kilowatts x hours),
so for example a 0.2kWh UPS could run a 100w (0.1kW) load for 2 hours.

Not convinced that is correct. My APC Smart UPS 700 is rated at a nominal
700W, ie it will deliver 700W but the runtime at that power level is at
best 10 minutes.

Yes, I see that thar rating in the wiki is kWh but I've not seen that used
as the headline rating of a UPS.

Most UPS' will have a rating in VA or KVA. This indicates the maximum
load[1] rather than the run time. The Capacity of the batteries in Ah
will be proportional to the run time. More professional units allow the
run time to be increased with additional battery boxes. It is worth
noting also that the internal inverter in the UPS will have some load
anyway and hence there will be a maximum run time even without any load
on the UPS. This can be as little as 20 mins on a small one.

[1] More significantly combined real and reactive load - so with much
computer related kit (especially older stuff) you need to allow for the
non unity power factor.

UPSes are also rated by their max continuous power output. The load
appliance(s) should not exceed this rating. Note its the load's VA
that matters rather than watts. For some loads VA = watts, and for
some their VA rating is greater than watt rating.

Ah, I'd swap these to around as the VA is more often quoted along with a
runtime at various power levels rather than an overall kWh rating,
certainly for smaller UPS units. Large industrial ones may well have their
ratings quoted differently.

IME, they often do it the same way on bigger boxes.

Finally UPSes are also rated by peak power output. Some appliances
draw well above running power for a brief period at startup. It would
be wrong to assume that if the UPS meets an appliance's run current it
would also meet the startup current requirement.

Add a warning that switching something on that takes a surge can trip the
UPS protection circuit when running on battery power. That same appliance
probably won't when the UPS is on mains power.

Even if you don't trip the UPS, you may glitch the power for long enough
to upset something else already powered. I deliberately put my big CRT
monitor a separate UPS from anything else that might not appreciate
being glitched.

(If you have a power cut while the computer is on, but the monitor is
off, and you find you need to turn the monitor on to close down the
system gracefully and get yourself out of whatever docs you left open.
it can be quite annoying if the monitor switch on surge resets the
computer! DAMHIK)


--
Cheers,

John.

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

On Thu, 31 Jul 2008 11:17:47 +0100, Andy Burns wrote:

Mention that the ADSL/cable modem and router(s) will need to be on the
UPS - not just the computer system.

If you want any decent runtime for a PC/monitor/xDSL etc you are going to
have some hefty battery storage. Best to forget a PC other than a laptop
when the power goes. Have one to enable clean automagic shut downs though.

Useful to put DECT basestation on UPS too, but also keep a wired phone
handy.

Some DECTs have batteries, personally I'd have a wired phone always
plugged in somewhere anyway.

--
Cheers
Dave.

On Thu, 31 Jul 2008 10:36:09 +0100, Rod wrote:

Various forms of glow stick/light can be very effective. Although
relatively expensive, they are very safe and can be stored for long
periods.

Yep, handy to give to the kids in the pitch dark. Also have very long
shelf life.

Simple glow-in-the-dark tabs/labels can help in locating door handles,
light switches, etc.

I bought some little tabs just for that purpose but No.1 Daughter removed
the few I put on within hours. She was about 2 at the time though, they
might stay there now.

--
Cheers
Dave.

Dave Liquorice wrote:
On Thu, 31 Jul 2008 11:17:47 +0100, Andy Burns wrote:

Mention that the ADSL/cable modem and router(s) will need to be on the
UPS - not just the computer system.

If you want any decent runtime for a PC/monitor/xDSL etc you are going to
have some hefty battery storage. Best to forget a PC other than a laptop
when the power goes. Have one to enable clean automagic shut downs though.

Useful to put DECT basestation on UPS too, but also keep a wired phone
handy.

Some DECTs have batteries, personally I'd have a wired phone always
plugged in somewhere anyway.


Must admit, I had assumed laptop earlier.

Good point re DECT. And perhaps 'keep your mobile charged' should also
be added to advice?

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

On Thu, 31 Jul 2008 16:40:51 +0100, Rod wrote:

Good point re DECT. And perhaps 'keep your mobile charged' should also
be added to advice?

As in don't rely on a charged mobile phone for communications? If your
power is off there is a reasonable chance that the power to the local cell
site is also off. Some have UPS back up for a hour or two, some autostart
gensets but the vast majority don't.

A BT provided wired phone will work for a considerable time from the
exchange batteries or genset. A cable company provided wired phone may not
be so resilient.

--
Cheers
Dave.

On Thu, 31 Jul 2008 15:13:47 +0100, John Rumm wrote:

(If you have a power cut while the computer is on, but the monitor is
off, and you find you need to turn the monitor on to close down the
system gracefully and get yourself out of whatever docs you left open.
it can be quite annoying if the monitor switch on surge resets the
computer! DAMHIK)

Same as me I suspect BTDTGTTS. B-) In my case just an ordinary 15" CRT
monitor not a big jobbie. I don't think LCD monitors have the big switch
on surge of CRTs.

--
Cheers
Dave.

Dave Liquorice wrote:
On Thu, 31 Jul 2008 16:40:51 +0100, Rod wrote:

Good point re DECT. And perhaps 'keep your mobile charged' should also
be added to advice?

As in don't rely on a charged mobile phone for communications? If your
power is off there is a reasonable chance that the power to the local cell
site is also off. Some have UPS back up for a hour or two, some autostart
gensets but the vast majority don't.

A BT provided wired phone will work for a considerable time from the
exchange batteries or genset. A cable company provided wired phone may not
be so resilient.

Agreed - not to rely on mobile. Just thought it was sensible to have
that charged up *as well* as non-mobile working.

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

On Thu, 31 Jul 2008 18:10:26 +0100 (BST), "Dave Liquorice"
wrote:

A BT provided wired phone will work for a considerable time from the
exchange batteries or genset.

Indeed. I still use proper phones with dials :-)

--
Frank Erskine

Dave Liquorice wrote:
On Thu, 31 Jul 2008 15:13:47 +0100, John Rumm wrote:

(If you have a power cut while the computer is on, but the monitor is
off, and you find you need to turn the monitor on to close down the
system gracefully and get yourself out of whatever docs you left open.
it can be quite annoying if the monitor switch on surge resets the
computer! DAMHIK)

Same as me I suspect BTDTGTTS. B-) In my case just an ordinary 15" CRT
monitor not a big jobbie. I don't think LCD monitors have the big switch
on surge of CRTs.

Its the degauss on most CRTs that does it. My 23" aperture grill screen
will glitch even my 1KVA UPS boxes...

--
Cheers,

John.

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

On Jul 31, 3:34*am, wrote:
Another one for your welcome input.... an intro to the backup power
options

OK, version 2... and hopefully the last version.

And a brief note - there seems to have been a lot of confusion around
UPSes, and since theres a fair bit to write about them I decided to
move the ratings info to a prospective UPS article rather than within
this one - it doesnt seem to belong here after all.

Oh, iron carbon batteries are he
http://www.wiki.diyfaq.org.uk/index....carbon_battery


Thanks, NT




There are lots of ways of providing '''Backup power'''. This article
introduces the various options, with their main features. Some of
these have their own articles that go into the option in more detail.


==Power options==
===Generator===
* how to detemine power needed
* noise
* maintenance
* cost
* service life (often very short)
* 2 strokes and starting reliability
* the Cult of the Listeroid
* connecting to mains wiring

===Torch===
[[Battery]] torches tend to turn out to have flat batteries. [[Nicad
battery|Rechargeable batteries]] are worse in this respect, with quite
high self discharge rates.

Wind-up and shake torches don't need batteries, so are more likely to
work when they haven't been used in ages. They don't run long on a
charge, but can be useful to see to get another power source running.

[[LED Lighting|LED]] torches give out less light and light of lower
CRI, but run longer, are much less prone to bulb failure and are far
more robust.


===Gas lighting===
Despite being historic technology, gas lighting has some advantages
over electrical power. The main one is its long term reliability,
which is hard to match using elecrical kit. Gas lights can be expected
to work for decades without attention or failure.

Gas cylinders don't discharge in storage, so power is always there
ready to go. This contrasts noticeably with rechargeable batteries,
which are prone to either
* being flat when wanted if not left on trickle charge
* having limited life if left on trickle

A small camping lantern will produce more light than a 60W incandesent
light bulb for several hours at maximum brightness. If longer run time
or less light is required they can be turned down and give really long
run times, 10 hours or more depending on cartridge size.

The quality of the light is quite good, and much better than the low
CRI and high CCT types of electric lighting, such as LEDs and
[[Fluorescent Lighting|cool white fluorescent tubes]].

Gas lights produce a lot of heat due to low efficiency, and with
suitable care this can be used to cook or heat water. Even a small
camping gas light will put out around 400w of heat, which is enough to
cook on.

The high heat output means it should be put somewhere it can't be
knocked over in use. Hanging from the ceiling is often practical.

Putting foil round half the globe produces nearly twice the level of
forward light.

Cost per volume of gas varies widely for different cartridge types.
High gas cost lights can be uneconomic purchases, even if cheaper
initially.


===UPS===
'''U'''ninterruptible '''P'''ower '''S'''upplies provide a mains feed
that's not interrupted in the event of a power cut. The switchover to
internal [[battery]] is instant.

Large whole building units are available, but nearly all UPSes sold
are plug-in items intended to run one or a few low power appliances,
typically a computer system. Small cheap units may only manage minutes
of backup time.

To avoid disappointment, the required capacity of UPS should be
calculated before purchase, otherwise its likely to fail to deliver
the run time wanted.


===Laptop===
A laptop is often a practical way to get computer time during power
loss.

Where TV is wanted to sedate the kids, a laptop with a USB TV card can
be cheaper than a UPS to run the main TV, and of rather more use.

Extra batteries can give more run time. As well as expensive Li-ion
laptop batteries, laptops can be run off [[Lead acid battery|lead
acids]] with higher capacity and lower cost per hour, or an [[iron
carbon battery]]. Manufacturer's instructions should be followed in
such cases.


===[[Lead acid battery]], charger, invertor===
A good option for people that already have most or all of the parts.
However the necessary bits and leads need to all be to hand when the
power cut happens, and the battery must of course be charged and
ready.


===Candles===
Though basic, candles are a workable way to provide occasional
lighting. £1 buys a lot of tea lights, but not a lot of light level.

Candles are associated with significant fire risk, so its only
sensible to use some means to keep the candle safe in use. Wall
sconces are effective, placing the candle high up out of reach,
especially of young kids.

Always keeping candles and matches in the same place makes finding
them in the dark easy. Finding them in a new location can be a
hopeless task in the dark.


===[[Emergency Lighting|Emergency escape lights]]===
Non-maintained lights will light up automatically when mains power
fails. (Maintained units are designed for a slightly different job.)

Run time typically 1-3 hours, typical cost £15-20.

[[Fluorescent Lighting|Fluorescent]] units generally give more run
time due to the much higher efficiency of fluorescent tubes.


===Rechargeable torch===
These are left permanently on trickle charge. Some can be set to come
on automatically when power goes off. Available light output and run
time vary.

Fluorescent torches generally give better run time, since the
[[Fluorescent Lighting|fluorescent tube]] is much more energy
efficient than the [[Filament Lamps|filament bulb]].

All share one defect, limited [[battery]] life, and will require
[[Nicad battery|re-celling]] after so many years. Cells with higher
capacity can give longer run time if required.


===[[Iron carbon battery]]===
The home made iron carbon battery can provide plenty of power at any
chosen voltage during a power cut. These are stored dry, and water is
added to activate them. Because of this, shelf life is indefinate.

Construction cost is trivial, they're easily replenished after use,
and can be built to any size for any load requirement. Very large
batteries are quite constructable.


===Luminaire backup pack===
Mains [[Fluorescent Lighting|fluorescent lights]] are available with a
battery backup pack built in which will light the tube when mains
fails. Be aware that battery operation is usually at much reduced
power. While popular in commercial premises, this is not one of the
cheaper options for domestic use, expect to pay anywhere in the region
of £80 or so. They also aren't generally styled for domestic use, but
this issue is easily sidestepped with [[Fluorescent Lighting|trough
installation]].


===12v battery & 12v lights===
[[Fluorescent Lighting|Fluorescent lights]] give several times the run
time per light output than [[filament Lamps]]. A practical option
where mains voltage isn't needed.

Its possible to feed 12v wiring to every room, and add a relay that
switches a 12v lighting system on when mains fails. This may be an
attractive option when carrying out work that permits running new low
voltage wires, such as major redecoration, rewiring, installing a
wired network, etc. See [[Low Voltage Wiring]].

A [[Lead acid battery]] requires a few minutes of maintenance every
couple of years to last well.


===Glowsticks===
Low light output and high price, but long shelf life, completely safe
to give to kids and keeps them amused.

Glow in the dark tabs can be added to door handles to help small
children navigate the dark.


===Paraffin lamp===
Old fashioned pressurised paraffin lamps (Coleman, Petromax etc) are
much cheaper to run than gas canister lamps, but a little knowledge &
time is needed to get them started. They're also not the safest
lighting option.


===Nothing===
Most people choose no back up power, and are quite happy to sit in
quiet for once. It can be a nice break in a hectic life, and quite
refreshing.


==Choice==
The usual question that's posed when choosing is 'What do you want
power for?'
* lighting
* ch/hw
* tv
* computer
* freezer
* cooking
* etc

What will that cost, and is it worth it? Now, more realistically, what
will do?


==Services==
===Cooking==
If power for cooking is needed, as well as the above options it can be
provided by any of:
* disposable charcoal BBQ tray
* wood/coal fire
* gas stove, either mains, bottled gas or camping canister type
* paraffin stove
* and maybe self heating instant meals

If considering these options, bear in mind that old fuel cookers such
as paraffin types can sometimes produce significant CO, and will
require proper ventilation or use outdoors.

===Phone===
Wired phones connected direct to the line should continue to work in a
power cut. Not all companies keep as much reserve run time at the
exchange as BT.

Mobile phones may stop working as most nearby cell towers have no
backup power source. A mobile with a flat battery will of course be
dead - obvious, but sometimes overlooked.

Cordless phones stop working if the base unit doesn't have a built in
[[Nicad battery|rechargeable battery]]. Those that do should continue
to work for a fair time if the battery is serviceable.

===Internet===
Dialuppers using a land line should have no problem for a while.
Wireless mobile net access will suffer the same fate as mobile phones,
and usually stop working.

Broadband services require power to the modem to work, otherwise net
access stops. Any routers will also need power if you want them to
work.

===TV===
[[TV aerial]] systems that include an [[Aerial amplifier|amplifier]]
will play dead during a power cut.

Set top boxes and anything else the aerial signal runs through will
also want power providing, or won't co-operate. However its not hard
to connect the [[Cable for TV aerials|aerial lead]] direct to the TV
to just get the 5 main channels.

===Computers===
Desktop systems and CRT monitors are both power hungry. Cheap plug-in
power backups won't run these for long, and in some cases won't run
them at all. Laptops are more practical.

Desktop systems with a CRT monitor on a UPS suffer a particular issue:
if the monitor is off when power is lost, switching it on tends to
glitch the backup power, which often resets the computer or shuts down
the UPS. This is due to the high initial current consumption of the
degauss circuit in nearly all CRT sets. Even a 1kVA UPS can be caught
out by this in some cases.

CRT monitors can be modded to sidestep this problem by putting the
degauss circuit on a switch, and normally leaving it off, but few
would bother for domestic use.


==Business use==
When using backup power for commercial premises, its helpful to
estimate how much business is lost in one power cut, and roughly what
this value adds to over say a 10 year life of a power backup system. A
quick calculation shows that UPSes are a no-brainer for many
businesses.

Bear in mind that power cuts are in practice due to [[Circuit faults|
on-premises faults]] as well as supply outages, and that getting an
electrician generally takes many hours.


==Connecting to house electrical circuits==
Care should be used in doing this, as its quite possible to kill or
injure a linesman if the right safeguards aren't in place. Integrating
the backup power source with the whole house wiring is more involved
than most DIYers are willing to do. Running an extension lead from
power source to appliance is a simpler option.


==Wiring Design==
Its possible to choose what appliances you want to work in a power
cut, and provide a separate circuit to run them, possibly with a UPS
to keep the circuit alive for a while. Very few of us go that far, but
some will wish to at design time.


==See Also==
* [[Special:Allpages|Wiki Contents]]
* [[Special:Categories|Wiki Subject Categories]]



[[Category:Electrical]]

On 2008-07-31 18:34:55 +0100, Frank Erskine
said:

On Thu, 31 Jul 2008 18:10:26 +0100 (BST), "Dave Liquorice"
wrote:

A BT provided wired phone will work for a considerable time from the
exchange batteries or genset.

Indeed. I still use proper phones with dials :-)

Number please, caller.

On Thu, 31 Jul 2008 23:52:50 +0100, Andy Hall wrote:

A BT provided wired phone will work for a considerable time from the
exchange batteries or genset.

Indeed. I still use proper phones with dials :-)

Number please, caller.

That was a handle not a dial...

Ask a youngster to make a phone call on a phone with a dial and they are
stumped.

--
Cheers
Dave.

In article 48924243@qaanaaq,
Andy Hall writes:
On 2008-07-31 18:34:55 +0100, Frank Erskine
said:

On Thu, 31 Jul 2008 18:10:26 +0100 (BST), "Dave Liquorice"
wrote:

A BT provided wired phone will work for a considerable time from the
exchange batteries or genset.

Indeed. I still use proper phones with dials :-)

Number please, caller.

Reminds me of a story I heard when I was working for GPT, 15
years back. A telephone exchange engineer was out on a long-term
assignment in India (IIRC) with his family, as often happened
when a large network infrastructure was being installed.

His kids got chatting to some local kids, and were talking
about the new phone technology daddy was installing.

"You'll be able to lookup someone's number, lift the receiver
and dial anwhere in the world."

The Indian kid replied:

"We don't need to do that. We just pick the receiver up and
ask to be connected".

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 2008-08-01 01:44:04 +0100, (Andrew
Gabriel) said:

In article 48924243@qaanaaq,
Andy Hall writes:
On 2008-07-31 18:34:55 +0100, Frank Erskine
said:

On Thu, 31 Jul 2008 18:10:26 +0100 (BST), "Dave Liquorice"
wrote:

A BT provided wired phone will work for a considerable time from the
exchange batteries or genset.

Indeed. I still use proper phones with dials :-)

Number please, caller.

Reminds me of a story I heard when I was working for GPT, 15
years back. A telephone exchange engineer was out on a long-term
assignment in India (IIRC) with his family, as often happened
when a large network infrastructure was being installed.

His kids got chatting to some local kids, and were talking
about the new phone technology daddy was installing.

"You'll be able to lookup someone's number, lift the receiver
and dial anwhere in the world."

The Indian kid replied:

"We don't need to do that. We just pick the receiver up and
ask to be connected".

That's a lovely story.

On the theme of GPT, I can remember planning and making a visit to
their site in Coventry. The address was New Century Park. It
sounded impressive and high tech with a name like that. Until one got
there. What they had omitted to mention was *which* century.

I suppose nowadays they have the three sausages on the roof.

wrote:
On Jul 31, 3:34 am, wrote:


Oh, iron carbon batteries are he
http://www.wiki.diyfaq.org.uk/index....carbon_battery

Somewhat surprising that there is just one hit on the entire web for
"Iron carbon battery". And that link is the interesting but confusing:

http://www.wiki.diyfaq.org.uk/index.php?title=Special:Random

So does that count as a googlewhack?

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

On Thu, 31 Jul 2008 23:52:50 +0100, Andy Hall
wrote:

On 2008-07-31 18:34:55 +0100, Frank Erskine
said:

On Thu, 31 Jul 2008 18:10:26 +0100 (BST), "Dave Liquorice"
wrote:

A BT provided wired phone will work for a considerable time from the
exchange batteries or genset.

Indeed. I still use proper phones with dials :-)

Number please, caller.

No - that's for phones _without_ dials.

:-)
--
Frank Erskine

In article 4892a2f1@qaanaaq,
Andy Hall writes:

On the theme of GPT, I can remember planning and making a visit to
their site in Coventry. The address was New Century Park. It
sounded impressive and high tech with a name like that. Until one got
there. What they had omitted to mention was *which* century.

GPT barely made it into the new century (renamed Marconi by
then), before going bust, so it wasn't a problem for long.

I suppose nowadays they have the three sausages on the roof.

I don't know what's happened to that site. It does look like
it's become Ericsson's now, and still called New Century Park.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 2008-08-01 09:29:09 +0100, (Andrew
Gabriel) said:

In article 4892a2f1@qaanaaq,
Andy Hall writes:

On the theme of GPT, I can remember planning and making a visit to
their site in Coventry. The address was New Century Park. It
sounded impressive and high tech with a name like that. Until one got
there. What they had omitted to mention was *which* century.

GPT barely made it into the new century (renamed Marconi by
then), before going bust, so it wasn't a problem for long.

I suppose nowadays they have the three sausages on the roof.

I don't know what's happened to that site. It does look like
it's become Ericsson's now, and still called New Century Park.

Just found it. It appears that they closed that site and transferred
to another close by.

wrote:

Oh, iron carbon batteries are he
http://www.wiki.diyfaq.org.uk/index....carbon_battery

Interesting, but curiously lacking in details of actually making the
thing. I assume one simply dips the carbon and steel electrodes in a pot
of salty water and obtains a voltage across them? How salty should the
water be?

Pete

In article ,
Huge writes:

You should be running software to monitor the UPS and gracefully shut down the
machine when the batteries start to run down.

APC provide a (vast, poorly documented, hideous) piece of software for their

Been there, tried that. It was responsible for more system downtime
than the mains failures, completely defeating the object of running
the UPS! Oh, and you forgot mention security vulnerabilities.
Maybe it got better in the 10 years since I last tried it?

Solaris normally has no problem just pulling the power cord
(particularly a server which is not very busy because most of its
clients lost their power already), so I ditched the software and
just let system die when battery ran flat. That always worked fine!

UPS's, but I strongly recommend the Open Source Network UPS Tools, instead;

http://eu1.networkupstools.org/

http://www.csociety.org/~delpha/winnut/

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In article ,
Huge writes:
On 2008-07-31, wrote:
On Jul 31, 3:34*am, wrote:
Another one for your welcome input.... an intro to the backup power
options

OK, version 2... and hopefully the last version.

Sorry, but would it be worth mentioning that many gas hobs will not operate
without mains power, the gas is cut off as a safety measure if the igniter
circuit is unpowered?

Could expand into consideration of appliances which will run
without electricity, if you are in an area particularly prone
to power cuts.

I have a Main gas multipoint water heater which still gives me
infinite hot water when the power's off, and I did have gas
wall heaters, some of which work with no electricity.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 1 Aug 2008 14:00:46 GMT, Huge wrote:

On 2008-08-01, Pete Verdon d wrote:
wrote:

Oh, iron carbon batteries are he
http://www.wiki.diyfaq.org.uk/index....carbon_battery

Interesting, but curiously lacking in details of actually making the
thing. I assume one simply dips the carbon and steel electrodes in a pot
of salty water and obtains a voltage across them? How salty should the
water be?

Ahh, some googling leads me to find that these are more usually called "iron
air" batteries.

And here's how to make one;

http://www.miniscience.com/projects/airbattery/

Where do you get the magnesium electrodes?

Mg is probably banned by the guvmint in this country.

--
Frank Erskine

Frank Erskine wrote:
On 1 Aug 2008 14:00:46 GMT, Huge wrote:

On 2008-08-01, Pete Verdon d wrote:
wrote:

Oh, iron carbon batteries are he
http://www.wiki.diyfaq.org.uk/index....carbon_battery
Interesting, but curiously lacking in details of actually making the
thing. I assume one simply dips the carbon and steel electrodes in a pot
of salty water and obtains a voltage across them? How salty should the
water be?
Ahh, some googling leads me to find that these are more usually called "iron
air" batteries.

And here's how to make one;

http://www.miniscience.com/projects/airbattery/

Where do you get the magnesium electrodes?

Mg is probably banned by the guvmint in this country.


No problem:

http://www.balancemotorsport.co.uk/products.asp?recnumber=21627

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

On Aug 1, 1:44*pm, (Andrew Gabriel) wrote:
In article ,
* * * * Huge writes:
On 2008-07-31, wrote:
On Jul 31, 3:34*am, wrote:

Another one for your welcome input.... an intro to the backup power
options

OK, version 2... and hopefully the last version.

Sorry, but would it be worth mentioning that many gas hobs will not operate
without mains power, the gas is cut off as a safety measure if the igniter
circuit is unpowered?

Could expand into consideration of appliances which will run
without electricity, if you are in an area particularly prone
to power cuts.

I have a Main gas multipoint water heater which still gives me
infinite hot water when the power's off, and I did have gas
wall heaters, some of which work with no electricity.

Thanks - will mention that.


Pete Verdon:

Interesting, but curiously lacking in details of actually making the
thing. I assume one simply dips the carbon and steel electrodes in a pot
of salty water and obtains a voltage across them? How salty should the
water be?

Thanks for pointing that out, I didn't realise more explanation was
needed. Yes, its as simple as that, with several cells hooked in
series. Salt concentration? I don't know, I just stuck a pinch in and
it was fine. Its not critical.


Another poster:

these are more usually called "iron
air" batteries.

And here's how to make one;

http://www.miniscience.com/projects/airbattery/

That's something different, related but different. And I note the
author seems to have had a lot of trouble getting a most simple cell
to work, has chosen some fairly inappropriate materials for it, and
given it a wrong name.


NT

On 1 Aug 2008 17:01:52 GMT, Huge wrote:

On 2008-08-01, Frank Erskine wrote:
On 1 Aug 2008 14:00:46 GMT, Huge wrote:

On 2008-08-01, Pete Verdon d wrote:
wrote:

Oh, iron carbon batteries are he
http://www.wiki.diyfaq.org.uk/index....carbon_battery

Interesting, but curiously lacking in details of actually making the
thing. I assume one simply dips the carbon and steel electrodes in a pot
of salty water and obtains a voltage across them? How salty should the
water be?

Ahh, some googling leads me to find that these are more usually called "iron
air" batteries.

And here's how to make one;

http://www.miniscience.com/projects/airbattery/

Where do you get the magnesium electrodes?

Frank, no offence, but is Google not working at your house?

I never use Google. :-)

--
Frank Erskine

On 2008-08-02 09:54:47 +0100, Huge said:

Ah. Well, I'm afraid if you want to employ me to do searches for you, you'll
have to pay my standard consultancy rate. )

The secret here is to price yourself out of the market. That way you
can't be accused of being uncooperative.

On 2008-08-02 14:22:54 +0100, Huge said:

On 2008-08-02, Andy Hall wrote:
On 2008-08-02 09:54:47 +0100, Huge said:

Ah. Well, I'm afraid if you want to employ me to do searches for you, you'll
have to pay my standard consultancy rate. )

The secret here is to price yourself out of the market.

I suspect I already am. )

Charm is another way ;-)

Andrew Gabriel wrote:

Been there, tried that. It was responsible for more system downtime
than the mains failures, completely defeating the object of running
the UPS! Oh, and you forgot mention security vulnerabilities.
Maybe it got better in the 10 years since I last tried it?

The modern versions of powerchute ain't so bad these days.

Alas my UPSs have RS232 serial connections rather than USB, and at the
time I had that particular problem I did not have enough serial
connections to spare for the UPS!

Solaris normally has no problem just pulling the power cord
(particularly a server which is not very busy because most of its
clients lost their power already), so I ditched the software and
just let system die when battery ran flat. That always worked fine!

Yup, most of my boxes seem to cope if that does happen.

--
Cheers,

John.

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