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Use the car as a temporary generator during black out ?

T

Tony P.

Jan 1, 1970
0
How difficult/expensive would it be convert an old yard tractor
(10hp) into a mobile generator for use in case of blackouts and
where would one find the necessary components?

That would probably work. But here is the secret - in any generator the
driving engine is rarely the most expensive part.

I'll bet you could find a power plant/generator pair where the power
plant is shot for cheap.
 
T

the Wiz

Jan 1, 1970
0
Is there such a device that you can plug into your car and is capable
of turning the car's DC 12V power into household 110V AC ? Please
don't laugh if this is a stupid idea, I am just wondering if the power
generated by the
small alternator on a running car would be enough to drive a force air
furnance during black out ?

My neighbour is buying an expensive Honda generator as a backup power
supply.
Since I can't afford to do the same and black out is not uncommon in
my area,
I am thinking if the alternator on my three cars can do the same trick
and
power at least the furnance during a winter black out ?

Appreciate if you can share your knowledge / experience.

Getting the generator is the easy part. Getting it connected to your house in a
safe manner can be much harder and potentially more expensive.

Most furnaces are hard-wired to the breaker/fuse panel - there is no cord you
can unplug and plug into the generator. Making a "suicide" adapter with a plug
on each end is not a good way ;-)

=========================

There are also non-electric ways to heat, light and cook.

A 22,000 BTU kerosene heater can heat 800 to 1000 sq ft on 3 to 4 of gallons of
kerosene per day.

The heater is about $120, kerosene is about $1.75/gallon.

A windup/solar am/fm radio (FreePlay) is about $70.

Camp stoves (Coleman) are under $100 and propane cylinders for a week's cooking
might be $10.

================

I'm not an off-grid person, I just happen to be prepared for the most likely
local problems.

I bought a kerosene heater in 1999 used it for the first time in January 2000
(during an ice storm - 36 hours without power is the longest so far).

I also have a older Coleman stove and lantern (left over from camping with the
kids) that use liquid "stove fuel" (basically low octane unleaded gasoline) and
my wife has several (mostly decorative) oil lamps - but they always have a
little fuel in them. Cooking on a liquid fuel stove is something of an art, but
I make great omelets ;-)

Oh yes, the home network and DSL have over an hour of backup from a small UPS.
There's also a car charger for the laptop. I have been known to use the laptop
by the light of an oil lamp ;-)

More about me: http://www.jecarter.com/
VB3/VB6/C/PowerBasic source code: http://www.jecarter.com/programs.html
Freeware for the Palm with NS Basic source code: http://nsb.jecarter.com
Drivers for Pablo graphics tablet and JamCam cameras: http://home.earthlink.net/~mwbt/
johnecarter at@at mindspring dot.dot com. Fix the obvious to reply by email.
 
A

Ad absurdum per aspera

Jan 1, 1970
0
It's not a completely silly question but you may conclude that this
isn't the best approach either.

The gadget that converts 12-ish V d.c. into 120V a.c. is called a
"power inverter." Punching that term into your favorite search engine
should yield plenty of websites about them. People use 'em to run
*small* 120V appliances in their car or sailboat or wherever. Doing
this is pretty inefficient, so the inverter sucks a lot of input
current and gets nice and hot.

Small ones (few hundred watts steady-state, a bit more than that peak)
are ubiquitously available for as little as $30, but those are best
thought of as a way to let the kids play video games in the back seat,
or perhaps for you to run handheld power tools at a jobsite.

Bigger ones can provide as much as a few kW steady state, but we're
now talking about prices that start well into three figures and run
into the four-digit range, especially if you want gourmet 120V
comparable to what the power company delivers, rather than "close
enough for government work" stuff.

The big ones also drain a battery in a big hurry, and are really
happier with a jumper-cable-style or (robustly) hardwired connection
than with the cigarette lighter outlet. The usual recommendation is
that you keep your car running while using them and/or employ a
separate, deep-cycle (marine-type) battery.


Your proposed application would need one of the huskier ones -- a
residential furnace often has a surprisingly substantial motor, 3/4 or
even 1 hp; and motors usually aren't too happy with either
undervoltage or trashy waveforms. Some advise allowing as much as 3x
the steady-state current draw at startup, so check the peak as well as
the steady-state specs of the inverter.

You might well decide that either there's a cheaper way to get AC in a
power outage or there's a better emergency way to keep the place
warm...

Cheers,
--Joe

PS. Also, educate yourself on how to properly hook up and use a
generator or other alternative AC source so you don't throw it into
the teeth of an overload... or (eeek!) energize a line that somebody
assumed to be dead. (Yeah, we all know what they say about "assume,"
but accidents happen somehow...)
 
D

Daniel Rudy

Jan 1, 1970
0
And somewhere around the time of 02/18/2004 13:53, the world stopped and
listened as JW contributed the following to humanity:
Is there such a device that you can plug into your car and is capable
of turning the car's DC 12V power into household 110V AC ? Please
don't laugh if this is a stupid idea, I am just wondering if the power
generated by the
small alternator on a running car would be enough to drive a force air
furnance during black out ?

My neighbour is buying an expensive Honda generator as a backup power
supply.
Since I can't afford to do the same and black out is not uncommon in
my area,
I am thinking if the alternator on my three cars can do the same trick
and
power at least the furnance during a winter black out ?

Appreciate if you can share your knowledge / experience.

What you have asked is not a stupid question, but alot of people have
thought along the same lines that you have. Yes, and no. It depends on
how much electrical power the furnace needs in order to start and run
the blower. If your alternator/battery can supply the power, then
great. Otherwise, you may want to invest in a real generator.
 
S

Spajky®

Jan 1, 1970
0
Is there such a device that you can plug into your car and is capable
of turning the car's DC 12V power into household 110V AC ? Please
don't laugh if this is a stupid idea, I am just wondering if the power
generated by the
small alternator on a running car would be enough to drive a force air
furnance during black out ?

something like this?
http://www.dynawatt.com/mobil.htm

-- Regards, SPAJKY ®
& visit my site @ http://www.spajky.vze.com
"Tualatin OC-ed / BX-Slot1 / inaudible setup!"
E-mail AntiSpam: remove ##
 
C

Chris Lewis

Jan 1, 1970
0
According to Bert Hyman said:
[email protected] (Andy Hill) wrote in
You'll want to check that again.

Indeed.

Most of the forced air furnaces I've seen use 1/4 or 1/3HP blower motors,
occasionally 1/2HP.

Even a very poorly efficient 1/2HP shouldn't be more than about 7 or
perhaps 8A. A gas generator should be at least double that to drive
the blower, and an inverter, probably triple.
 
A

Andy Hill

Jan 1, 1970
0
Bert Hyman said:
[email protected] (Andy Hill) wrote in


You'll want to check that again.
Sometimes when one pulls numbers out of one's *ss, they stink a bit. OK,
overstating the case a for a residential furnace. Still strikes me as a
marginal idea, at best.
 
B

Bert Hyman

Jan 1, 1970
0
[email protected] (Andy Hill) wrote in
Sometimes when one pulls numbers out of one's *ss, they stink a
bit. OK, overstating the case a for a residential furnace. Still
strikes me as a marginal idea, at best.

For a ->true emergency, it might be OK. But, an inverter with enough
oomph to handle the motor starting loads would still be a big
purchase. If you're serious about this, spend the bucks and get a
real generator and a real transfer switch.

All this has a certain immediate interest to me since I was awakened
at 4AM today by the shriek of my CO detector as it died from a power
outage. Power's back on now (I called home and the answering machine
picked up), but next time, who knows?
 
A

Art Todesco

Jan 1, 1970
0
Actually, maybe you overstated for newer blowers. However, some
of the older ones can be that high. My old furnace, replaced
about 15 year ago and built in 1970, ran pretty close to 10 amps.
 
R

Robert Hancock

Jan 1, 1970
0
I'd guess that the full-load or startup amperage on the motor could be that
high, but I doubt many furnace blowers would take that much current once
they were running..
 
C

Chris Lewis

Jan 1, 1970
0
According to Robert Hancock said:
I'd guess that the full-load or startup amperage on the motor could be that
high, but I doubt many furnace blowers would take that much current once
they were running..

The usual plate ratings on motors are "worst case full load" (delivering
full rated power under worst case manufacturing tolerance and supply voltage).

An efficiently matched motor and blower will be pulling "full load"
(not necessarily "worst case", but close) amps all the time. This goes
for pumps and compressors too.

Startup surge is 2-3 times that (and not listed on the plate).

In other words, a 10A blower motor _will_ pull close to 10A continuously.
20-30A startup surge.
 
K

KLM

Jan 1, 1970
0
Is there such a device that you can plug into your car and is capable
of turning the car's DC 12V power into household 110V AC ? Please
don't laugh if this is a stupid idea, I am just wondering if the power
generated by the small alternator on a running car would be enough to drive a force air
furnance during black out ?
When there was a huge ice storm that knocked out the grid in Quebec
and Ontario a few years back I mused about the same problem, how to
get the furnace running without power and avoid the freeze damage to
my home, any home.

This is a thought experiment. I have a natural gas central heating
system. The thermostat and gas valve system works off a small 24Vac
transformer. The fan motor is 1/2hp 115Vac. Its not too hard to
jury rig a stationary exercise bicycle to turn the furnace blower fan
and get the air circulation going. If I hook up a 12 Vdc car battery
to a small 115Vac inverter thence to the 24V transformer can I get the
furnace going and the house heated in an emergency? Can the furnace
valve system work off 24Vdc (two car batteries)? The power draw on
the battery to run the 24Vac parts is minimal so it shouldn't be
necessary to use the car to recharge the battery often.
 
B

Bill Vajk

Jan 1, 1970
0
KLM said:
On 18 Feb 2004 13:53:31 -0800, [email protected] (JW) wrote:
When there was a huge ice storm that knocked out the grid in Quebec
and Ontario a few years back I mused about the same problem, how to
get the furnace running without power and avoid the freeze damage to
my home, any home.
This is a thought experiment. I have a natural gas central heating
system. The thermostat and gas valve system works off a small 24Vac
transformer. The fan motor is 1/2hp 115Vac. Its not too hard to
jury rig a stationary exercise bicycle to turn the furnace blower fan
and get the air circulation going. If I hook up a 12 Vdc car battery
to a small 115Vac inverter thence to the 24V transformer can I get the
furnace going and the house heated in an emergency? Can the furnace
valve system work off 24Vdc (two car batteries)? The power draw on
the battery to run the 24Vac parts is minimal so it shouldn't be
necessary to use the car to recharge the battery often.

Consider permanently replacing the blower motor with a 24Vdc
unit and a transformer/rectifier for ordinary use. A sturdy
bank of car batteries can power your heating plant often
enough to keep a house from freezing for several days. A
small inverter (400 watts is less than $40 at Sams Club)
can power the control system.

OTOH it doesn't take a very large generator to run a furnace.
Natural_gas/propane fired is advised.
 
J

James C. Reeves

Jan 1, 1970
0
| An efficiently matched motor and blower will be pulling "full load"
| (not necessarily "worst case", but close) amps all the time. This goes
| for pumps and compressors too.
|
| Startup surge is 2-3 times that (and not listed on the plate).
|
| In other words, a 10A blower motor _will_ pull close to 10A continuously.
| 20-30A startup surge.
| --
| Chris Lewis, Una confibula non set est
| It's not just anyone who gets a Starship Cruiser class named after them.

That's interesting. My oil-burner furnace is on a 15 amp circuit breaker. The
largest draw seems to be greatest when the oil pump fires up, not when the
blower starts up. I don't think the typical furnace blower motors are even
close to 10A running.
 
D

Don Kelly

Jan 1, 1970
0
James C. Reeves said:
| An efficiently matched motor and blower will be pulling "full load"
| (not necessarily "worst case", but close) amps all the time. This goes
| for pumps and compressors too.
|
| Startup surge is 2-3 times that (and not listed on the plate).
|
| In other words, a 10A blower motor _will_ pull close to 10A continuously.
| 20-30A startup surge.
| --
| Chris Lewis, Una confibula non set est
| It's not just anyone who gets a Starship Cruiser class named after them.

That's interesting. My oil-burner furnace is on a 15 amp circuit breaker. The
largest draw seems to be greatest when the oil pump fires up, not when the
blower starts up. I don't think the typical furnace blower motors are even
close to 10A running.
Your oil pump likely has a heavier starting load than the blower. This
depends on the fluid and the type of pump/blower.
Your breaker is designed to handle short term overloads (as are fuses). It
will typically have an inverse time overcurrent characteristic. That is- the
time to trip is inversely proportional to the current (within limits) so
that short term high inrush currents can be handled. Otherwise you would be
plagued with unnecessary trips and never get a motor started unless you
wrapped a string around its shaft and started it as a top. A motor may draw
3-7 times rated current on starting. Look at the full load current listed
on the nameplate rather than the "power" listed. It is more meaningful.
 
D

Don Kelly

Jan 1, 1970
0
KLM said:
When there was a huge ice storm that knocked out the grid in Quebec
and Ontario a few years back I mused about the same problem, how to
get the furnace running without power and avoid the freeze damage to
my home, any home.

This is a thought experiment. I have a natural gas central heating
system. The thermostat and gas valve system works off a small 24Vac
transformer. The fan motor is 1/2hp 115Vac. Its not too hard to
jury rig a stationary exercise bicycle to turn the furnace blower fan
and get the air circulation going. If I hook up a 12 Vdc car battery
to a small 115Vac inverter thence to the 24V transformer can I get the
furnace going and the house heated in an emergency? Can the furnace
valve system work off 24Vdc (two car batteries)? The power draw on
the battery to run the 24Vac parts is minimal so it shouldn't be
necessary to use the car to recharge the battery often.
 
D

Don Klipstein

Jan 1, 1970
0
When there was a huge ice storm that knocked out the grid in Quebec
and Ontario a few years back I mused about the same problem, how to
get the furnace running without power and avoid the freeze damage to
my home, any home.

This is a thought experiment. I have a natural gas central heating
system. The thermostat and gas valve system works off a small 24Vac
transformer. The fan motor is 1/2hp 115Vac. Its not too hard to
jury rig a stationary exercise bicycle to turn the furnace blower fan
and get the air circulation going. If I hook up a 12 Vdc car battery
to a small 115Vac inverter thence to the 24V transformer can I get the
furnace going and the house heated in an emergency? Can the furnace
valve system work off 24Vdc (two car batteries)? The power draw on
the battery to run the 24Vac parts is minimal so it shouldn't be
necessary to use the car to recharge the battery often.

The AC output of automotive inverters should be good enough for that.
The usual automotive inverter output is what they call a "modified sine
wave", which is more like a "modified square wave". The RMS value of the
output is 120 VAC or reasonably close. The waveform goes like 3/8 cycle
positive, 1/8 cycle zero, 3/8 cycle negative, 1/8 cycle zero.
The RMS voltage of the 60 Hz (or fundamental frequency) component alone
will be a little short of 120 VAC (or tal RMS voltage), and lamps that use
ballasts may run a little dim. Motors will be not quite full blast and
may give noisier vibrations from the harmonics but will basically work,
and should not have trouble unless they barely work with true sine 60 Hz
full 120 VAC. I imagine a motor will heat up a little more with the
different waveform with "slightly wrong" RMS voltage of fundamental
frequency compinent alone, although this should only be a big deal if the
design or condition of the motor and/or the equipment using it is already
marginal.
DISCLAIMER - NO WARRANTY BY ME, especially for monetary amounts in
excess of fees that I get from you for making this post. :)

- Don Klipstein ([email protected])
 
J

Jim Land

Jan 1, 1970
0
---------
The problem will be "how long can you drive the fan effectively" 2
minutes? 5 minutes? What condition are you in? A nominal figure for a
human is (was? ) about 1/7 HP continuous. Estimated air flow less than
10% of normal. --

And who is going to stay up all night to ride the bicycle periodically to
keep the furnace working?

I suggest a more practical thought experiment would be to power the furnace
blower from the same 115vac inverter that runs the thermostat and gas
valve, keeping the 12vdc battery charged running the car engine.

Oh, and if you're enchanted with pedalling a bicycle to save energy, hook
an alternator to it and charge the battery. And don't forget the body heat
you'll generate pedalling... that'll warm the house too. Or at least it'll
warm you....
 
A

Andy Hill

Jan 1, 1970
0
Bill Vajk said:
OTOH it doesn't take a very large generator to run a furnace.
Natural_gas/propane fired is advised.
Hmmm. That's an interesting idea. Who are the quality names in NG and/or
propane-fired gensets?
 
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