Petrol Generator to Power a Cement Mixer
Pat
would be need to power an electric cement mixer. Am about to start
building a house and I hope to do the base myself. We don't have
electricity yet so I was thinking about buying a generator. Can anyone
give me advice. all replies will be appreciated.
Hendy7
"Pat" <mchugh_...@emc.com> wrote in message
news:4e85ee95.04061...@posting.google.com...
Christian McArdle
>> Can anyone give me advice. all replies will be appreciated.
And don't forget how useful it would be for the millions of other jobs apart
from running the mixer. I would strongly recommend getting a 110V version
and running 110V tools. You may find it an idea to get one cheap on eBay and
sell it when you've finished. You may even make a profit!
Christian.
N. Thornton
Look on the ratings plate on the mixer, tell us what the current
consumption is in amps. Your gen will need to supply that plus a
generous margin for starting.
But as was said, a more powerful 3kVA or even 5kVA machine will run a
lot more besides.
I cant see the sense in going 110v though, maybe someone else will
comment on that.
Regards, NT
Grunff
Others have answered your genny question - but can I ask - why do you
want to mix the base by hand? Buying ready mixed concrete is far more
cost effective, even if you costed your time at nothing.
--
Grunff
Will
>On 15 Jun 2004 12:47:49 -0700, big...@meeow.co.uk (N. Thornton) wrote:
>
>>
>>Look on the ratings plate on the mixer, tell us what the current
>>consumption is in amps. Your gen will need to supply that plus a
>>generous margin for starting.
>
>Yes, I find my 4kVA Honda will not restart my 2kW compressor unless
>the air tank is fully discharged first, runs fine once its going
>though even with 80psi in the tank.
>
I would suggest that there is something wrong with your
compressor. Starting under load is a recognised problem with electric
motors, so much so, that all the compressors that I have seen
decompress the pump part of the unit after it cuts out, to alleviate
it.
--
Regards,
Will.
N. Thornton
With many loads if youre caught short you can use a series load to
start the motor at reduced power: but that wouldnt work for a
compressor where you need the full power output at start.
Regards, NT
Pat
for the dead work that I need to do by hand (Engineer isn't too gone
on this bag of mortar that you can buy from the readymix companies).
The deadwork is quite substantial.... i.e. in 1 corner I have to bring
it up 1.75 metres. I will indeed be getting ready mixed concrete for
the floor area and foundations.
I will check the plate on the mixer and get back with what it says.
Have been told that a 3.5 KVA would be sufficient. There is a big
difference in price betweeen 3.5 KVA and 5KVA.
Dave Liquorice
> I cant see the sense in going 110v though, maybe someone else will
> comment on that.
Most small gennies have 110/240 outlets anyway. As for any benefit it
really depends on how the generator is wired and earthed. But I don't
want to open *that* can of worms again...
--
Cheers new...@howhill.com
Dave. pam is missing e-mail
Dave Liquorice
> Others have answered your genny question - but can I ask - why do
> you want to mix the base by hand? Buying ready mixed concrete is
> far more cost effective, even if you costed your time at nothing.
Not mention that you are talking a *serious* amount of concrete for a
base, read lots of tonnes. Back of fag packet, 30cm thick base, over
a 10 x 10m area is 30m^3... An ordinary site mixer would take
forever, I'd be worried about the joins between each batch and getting
consistenacy of mix across the base.
Christian McArdle
> base, read lots of tonnes. Back of fag packet, 30cm thick base, over
> a 10 x 10m area is 30m^3...
30m3 is 5 standard concrete mixer trucks.
Christian.
use...@isbd.co.uk
>
> I will check the plate on the mixer and get back with what it says.
> Have been told that a 3.5 KVA would be sufficient. There is a big
> difference in price betweeen 3.5 KVA and 5KVA.
It must be a big mixer if it's taking 3.5kVa, that's 5hp which sounds
a lot to me for a concrete mixer. Maybe I'm wrong though.
(OK, I know 3.5kVa isn't 3.5kW but the power factor can't be all that
bad can it?)
--
Chris Green
Dave Liquorice
>> Back of fag packet, 30cm thick base, over a 10 x 10m area is
>> 30m^3...
>
> 30m3 is 5 standard concrete mixer trucks.
Flipin 'eck! Is my maths about right? I guess a base 10 x 10m is quite
large but even half that, for a 5m (16') square house, is still a lot
of concrete. Are bases 30cm (12") thick?
Christian McArdle
It sounded right to me, although I always imagined house foundations being
trench things, rather than rafts.
When I was considering concrete for my conservatory and shed base, I
calculated it would need an entire truck. A house would need much more.
Christian.
Tony Bryer
> Flipin 'eck! Is my maths about right? I guess a base 10 x 10m is quite
> large but even half that, for a 5m (16') square house, is still a lot
> of concrete. Are bases 30cm (12") thick?
I've lost the beginning of the thread but if you're not driving HGV's on
them, no. Domestic floor slabs are generally 100mm.
A useful tip, which I found out too late, is that if you're not putting
a polythene dpm under the slab put a polythene sheet (of any thickness)
there anyway. It saves losing a lot of concrete and grout into the
hardcore and makes finishing the slab a lot easier.
--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk
Free SEDBUK boiler database browser http://www.sda.co.uk/qsedbuk.htm
Dave Liquorice
>> Have been told that a 3.5 KVA would be sufficient. There is a big
>> difference in price betweeen 3.5 KVA and 5KVA.
>
> It must be a big mixer if it's taking 3.5kVa, that's 5hp which
> sounds a lot to me for a concrete mixer.
No 3.5KVA genny to start the mixer. Motors need significantly more
power to start than to run. Rough rule of thumb: genny kVA = motor kVA
* 2. So the mixer is probably rated around 1.2kVA.
N. Thornton
At a density of 1.2 - 1.6 thats 36 - 48 tonnes. What fun they'll have :)
Regards, NT
N. Thornton
Pat
about my sanity if I was doing that. Engineer is looking for 150mm
floor over an area of 222sq m. I know its big but we wanted a 2 storey
but planning said no way. Its just the mortar for alot of dead work.
Good point on the hardcore taking extra concrete. Engineer wants a
sand blinding bed.... must try and get some cheap crap sand for that.
Have a 1.2Kw generator that just doesn't seem to be driving the mixer
as well as it should. Gets really mad at me if I fill it more than 3
quarters. If I was to buy a new generator I'd like it do be of use for
other tools etc. Not much good with the power and voltages etc. Can
someone explain the 110V Vs 230V
Thanks for all your replies..... very much appreciated
Christian McArdle
230V is obviously the same as household electrics, with a neutral (0V) and
live (230V).
110V uses two lives at anti-phase to give a maximum of 55V to earth, making
it fundamentally safer when working outdoors on a building site. You'll find
the most building sites use 110V. You may find a generator with both 230V
and 110V outputs, which is the best of both worlds. Most contractors used to
working on building sites will have 110V tools, although some of the later
indoor trades (such as plumbers) might be on 230V.
http://www.tooled-up.com/Product.asp?PID=27097
http://www.toolstation.com/search.html?searchstr=generator
Christian.
N. Thornton
If you add an RCD theres no real safety difference (without one there
is). 240v is compatible with far more kit than 110, unless you have a
building co that kitted up with all 110 before 240 RCD'ed became
permitted.
BTW Which complains, the gen or the mixer?
Regards, NT
Rick Dipper
I have a petrol cement mixer, old but works, I was going to eBay it
for 100 quid and up, for 100 you can have it. It in corwen, north
wales.
Rick
Dave Liquorice
> 230V is obviously the same as household electrics, with a neutral
> (0V) and live (230V).
Er not quite. On a generator you have two phases 180 deg apart and
230v between them. Only if one of the windings of the generator is
bonded to earth (as in large copper stake hammered in to the ground)
do you get the unbalanced system you describe.
> 110V uses two lives at anti-phase to give a maximum of 55V to earth,
Only if there is a center tap to the windings that is bonded to earth.
Other wise the two phases float, either can contact "earth" with no
problem but if one does the other is at 110v wrt to earth.
Owain
110V big yellow round plugs
230V big blue round plugs
:-)
Owain
Pat
> I have a petrol cement mixer, old but works, I was going to eBay it
> for 100 quid and up, for 100 you can have it. It in corwen, north
> wales.
>
Cheers Rick but unfortunately I am in the Rep of Ireland. Sorry for
busting in on this UK DIY site.
The Genny complains a bit.... if too much goes into the mixer
sometimes it will just stop..... plus it doesn't seem to be turning
the mixer as fast as it should.
Dave Liquorice
> The Genny complains a bit.... if too much goes into the mixer
> sometimes it will just stop..... plus it doesn't seem to be turning
> the mixer as fast as it should.
Hasn't got enough grunt, you need a bigger one... Look at the mixers
rating plate take the power and double it to get a ball park figure
for a generators rating then be generous. So if it comes out at 2.4kVA
and you have a choice of 2.5 or 3kVA gennes go for the 3kVA one.
N. Thornton
> The Genny complains a bit.... if too much goes into the mixer
> sometimes it will just stop..... plus it doesn't seem to be turning
> the mixer as fast as it should.
Sounds like genny underrated then. But... have you had it serviced?
engines can lose a lot of power through off ignition or valve timing,
dirty plugs, clogged air filter, dirty jets, falling comperssion, etc.
Regards, NT
N. Thornton
Just thought...
IIRC the gen's a 1.2kVA one? If so, if you plug a 1kW heater into it
it should be as happy as pie. If it struggles and falters then
somethings amiss with it. It can be expected to drop in speed very
slightly, but thats all.
Regards, NT
Pat
Have been pricing a new 3.5KVa and it works out at about 550 Euro
think that is about 350 GBP. Not sure if I need to spend that kind of
money. Am thinking of what other uses it would have. My other option
for the mixer is to get a tractor powered one second hand. Am lucky
enough to have a tractor so it might be economical...... will have
alot of other work for it. Am just weighing up the advantages of the
new genny and don't think its a good investment. Anyone argue
differently?
Thanks for all your replies!!!!
g.harman
If the tractor is suitable then it is possible to get generators that
fit on the linkage and run from the PTO .
That could be another option.
Might be worth enquiring in an agricultural machinery supplier or
scanning the list on some farm auctions.
G.Harman
Dave Liquorice
> If the tractor is suitable then it is possible to get generators
> that fit on the linkage and run from the PTO .
> That could be another option.
IMHO getting a bigger generator to power the mixer is much more
versatile than a PTO mixer that can only mix.
However I don't think running the tractor to get a couple of kW of
power would be particularly fuel efficient. Of course if the tractor
is burning red diesel the economics are very much different compared
to white diesel or petrol...