inverter for 1500w air compressor
Submitted: Tuesday, Nov 04, 2003 at 16:18
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gunzo
hello
I own a HJ60 diesel landcrusier with a duel battery set up and do 99% of my 4x4 driving is on sand, accessing surfing and fishing locations between Hawks Nest and Forster (Myall lakes area) in NSW. On these regular weekend and holiday trips I will be on and off the sand 3 to 4 times a day.
My tyres are 16x285x75 and using my fathers $400 12v aircompressor the tyres take over 6mins each to pump from 12psi to 30psi , more than 25mins! each time off the beach.
Looking at a 12v air compressor comparrison in 4x4 monthly, I noted that even a top of the range $1600 12v compressor will not peform much better...! Am I destined to spend hours each weekend I spend up the coast waiting for my tyres to inflate.?
I looked into endless airs "fan belt" driven compressor, this unit would pump my tyres up 10x faster than the best 12v compressor! and would price up at less than $1000 (unit +piping+tank+accessories) but install space is a problem with a/c , power steer,radiator reserve, etc and also a hassell to do myself.
So down to the local hardware I go and
check out the specs on some 1500w 240v 6 to 8 amp air compressors (only $150 ) and their cfm ratings suggest that these small 24L portable units will pump about 5 to 6 times faster than the $1000+ 12v compressors. and I can get a 1500w inverter for around $600 or a 2000w for 2 or 300 dollars more .
My questions are; 1) Will the batteries handle it.?
2) Will I have to keep the engin running?
3) The duel batteries have a 60amp isolator switch/(connector?),the amp draw will be around 135 amps from the compressormay be more, is this a problem.? as the alternator is probably only hooked up to the start battery and charges the secondary battery through the isolator(when switched"on")
4) Has anyone seen or installed a similar setup drawing this many amps/watts.? When I scearched the
forum on
inverters I could only find reference to low watt or long use items.
Any advice or coments would be much appreciated.
Thanks
Scott.
Reply By: GaryInOz (Vic) - Tuesday, Nov 04, 2003 at 16:45
Tuesday, Nov 04, 2003 at 16:45
Just a few random thoughts.....
Have you considered the possibility of using a 12 volt motor to drive the compressor? Something along the lines of a small winch motor?
It does seem pointless and very inefficient to go from 12 V to 240 V simply to turn a shaft to a compressor. The start up current on a typical 240 V motor is about 5 times its normal running current, and you would need to factor this in with your inverter choice. Sems like you are trying to spend big bucks to save yourself small bucks.
There are a selection of medium to larger 12V compressors available (one of whose name escapes me at the moment) which would seem to fill you needs. What you really need is a medium sized compressor connected to a 30-40 litre tank which gets filled as you are driving, rather than trying to generate large quantities of air at the time of airing up.
Other options...
Modify a "Christie" stationary generator by hanging the compressor directly on the front instead of the alternator.
AnswerID:
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Follow Up By: GaryInOz (Vic) - Tuesday, Nov 04, 2003 at 19:06
Tuesday, Nov 04, 2003 at 19:06
Ibelieve the name of the compressors was Clisbyavailable from Big Balls Offroad. Capable of decent L/min and quite quick.
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Follow Up By: GaryInOz (Vic) - Tuesday, Nov 04, 2003 at 19:19
Tuesday, Nov 04, 2003 at 19:19
The Clisby's are either 1/3 or 1/2 HP which equates to about 20-30 amp at 12 Volts. Much better than the 165 amp option and considerably smaller than CO2 tanks. At 55 secs from 8-35 psi in 55 secs I think that would answer your problems totally (5 mins to do all tyres).
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Follow Up By: GaryInOz (Vic) - Tuesday, Nov 04, 2003 at 19:22
Tuesday, Nov 04, 2003 at 19:22
I should proff read, err....proof read befor I post................
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Follow Up By: gunzo - Tuesday, Nov 04, 2003 at 20:50
Tuesday, Nov 04, 2003 at 20:50
the clisby soundes inpressive but im sceptical of the claim of a 35inch tyre inflated from 8 to 35 in 55 seconds withits 2.5cfm and 35 amps and at what pressure is the2.5 cfm delivered?
4x4 monthlys accesory gide compares 9 compressors, the best performers,(Flash air, Super pump and Twin tongue) all took over 2/12 minuts (over 150 seconds) on each 31x10.5x15inch tyre. 2 were JUST under in amps and cfm yet unlimited rating compared to 10 or 20 mins
on clisby. The Flash air unit tested at 3.12cfm@30psi and a wopping 65amp draw yet this unit also took over 2/12 mins. how can the clisbys performance be so much better????????????
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Reply By: Member - Bob - Tuesday, Nov 04, 2003 at 16:58
Tuesday, Nov 04, 2003 at 16:58
Scott,
there are only 3 options for you:
i. compressor with its own petrol motor (disadvantage is weight)
ii. endless air (disadvantage is space in engine bay)
iii. take cylinders of nitrogen or CO2 (disadvantage is refilling cyls)
Forget about 12 volts,
inverters etc. Grossly inefficient, expensive etcBob
AnswerID:
36199
Reply By: srowlandson - Tuesday, Nov 04, 2003 at 16:59
Tuesday, Nov 04, 2003 at 16:59
If speed is what your after, checkout the New Air-up Co2 Systems.
Refills about $15-20 a fill, dual bottle system is the best.
We have one, and you can't beat it for speed of airing up, and ease of re seating beads. Will operate air
tools with ease, and they have a bracket to mount the tank on the spare wheel carrier.
http://www.offroadshop.com.au/air-accessories/
Steve
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Follow Up By: Bonz (Vic) - Tuesday, Nov 04, 2003 at 18:45
Tuesday, Nov 04, 2003 at 18:45
hear hear...at $800 roughly setup cost its the go for you methinksLaterally Literal
Seriously Cerebral
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Reply By: Member - Eskimo - Tuesday, Nov 04, 2003 at 17:16
Tuesday, Nov 04, 2003 at 17:16
A standard 1500 or 200 watt inverter is not any good. A 240 motor will take approx 6/7 times full load current to get it going. A compressor has a top and bottom dead centre and this is where the starting current is used. Ask the experts like Jaycar for which inverter will suit that size motor and compressor...and a humble warning....dont expect to be able to afford the inverter to suit.
A belt driven comp is good I believe.
Has any one ever thought of using a cylinder of industrial air or nitrogen ... a regulator is a must. A standard BOC cylinder holds about 2000 psi while my dive cylinder holds about 300 bar (or a bit over 400 psi)
Does any one have any figures on how many tyre fills (275 x 16) you can get out of BOC "D" size cylinder???Wow! am I cute
If yer ain't fishing, Yer ain't livin
Richard
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Follow Up By: ToyMotor - Tuesday, Nov 04, 2003 at 22:00
Tuesday, Nov 04, 2003 at 22:00
I often used my dive cylinder to pump up tyres before I got a decent compressor, (incidentally most dive shops will fill to about 200-220 bar, which is 3000 - 3300 psi, 300 bar [4,500 psi] is probably the
test pressure) You get a few fills even from an "empty" cylinder. The advantage with CO2 is of course the much lower pressure in the cyl., and the much larger volume of gas per cylinder, as it is in liquid form in the cylinder.
Cheers
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Follow Up By: GaryInOz (Vic) - Tuesday, Nov 04, 2003 at 22:56
Tuesday, Nov 04, 2003 at 22:56
My objection to carrying any sort of gas is the fact that you have a charged cylinder (potential missile when heated) somewhere in the vehicle that is not adequately strapped down. CO2/N2 isjust as lethal (asphyxiation) as O2 is (combustible gas). The only really safe "gas" is air as it will not really change the dynamics of a fire or survival in the event of a serious accident.
YMMV
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Follow Up By: srowlandson - Wednesday, Nov 05, 2003 at 06:23
Wednesday, Nov 05, 2003 at 06:23
An advantage of Co2 is the bottle isn't under the same pressures as other bottles such as a scuba tank. If the head is knocked off, it isn't a missile, you clud hold it in your hand, as the pressures are not great.
We carry ours on a bracket on the rear door. Safe and sounds outside the vehicle.
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Follow Up By: Member - Eskimo - Wednesday, Nov 05, 2003 at 07:46
Wednesday, Nov 05, 2003 at 07:46
ToyMotor,
My dive tank is marked TP465 bar and the
shop fills it to 300 bar. Its a steel tank and although heavy than alloy the air lasts a lot longer. Also smaller.
As I carry oxygen every day and have been doing so for the last 35plus years, and my work colleagues have and do the same, and the fact that I have not personally met anyone (and nor have my work colleagues), who has had the top of a high pressure tank knocked off I consider the possibly of it happening very very unlikely if proper storage and fastening methods are employed.Wow! am I cute
If yer ain't fishing, Yer ain't livin
Richard
FollowupID:
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Reply By: JohnH - Tuesday, Nov 04, 2003 at 19:04
Tuesday, Nov 04, 2003 at 19:04
As eskimo said, I looked at the BOC type of option, the regulator was a bit pricey, around $300 but the bottles are fairly cheap second hand and pressure tested. The query I had was volume of the cylinder. I think you could manage quite a few refills and for $10 - 20 is worth it I think. All you need to do is establish the voulume in litres of air that your tyres need and then these fellas can work it all out for you. The volume is the hard part. If you figue it all out let us know, I think it's the best option personally.
Good Luck.
JohnH.
AnswerID:
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Follow Up By: Member - Eskimo - Wednesday, Nov 05, 2003 at 10:20
Wednesday, Nov 05, 2003 at 10:20
johnh you could use a second hand oxygen regulator from an oxy/acetylene set if it will deliver up to say 40 psi.
BUT ONLY FOR AIR USE...OXY AND OIL OR GREASE DO NOT MIX...IE. DO NOT RE-USE THE REGULATOR FOR ANY OTHER USE.
Wow! am I cute
If yer ain't fishing, Yer ain't livin
Richard
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Reply By: Time - Wednesday, Nov 05, 2003 at 07:44
Wednesday, Nov 05, 2003 at 07:44
Why not buy and install a second "standard" 12V unit and run the two units at the same time, cut the 25 mins in half! Sounds like a lot less hassle to me.
Cheers
Buggerlux
AnswerID:
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Follow Up By: Wazza (Vic) - Thursday, Nov 06, 2003 at 06:10
Thursday, Nov 06, 2003 at 06:10
You're onto it Buggerlux.
I bought a Blue Tounge compressor, and then got an ARB fitted under the bonnet when I had the diff locks put in. The Blue Tongue sat around the shed for a bit, and then I mounted it behind the back
seat. Both compressers are plumbed together, and the Blue Tongue works through a relay taking power from the ARB's pressure cutout, so it can't work unless the ARB is running first. Result:
Exactly 2 minutes to fill a 285/75/16 from 18psi to 38psi.
There are second hand compressors (ARB, Blue Tongue, etc) around all the time for about $250 harldy used. A few Air fittings ($40 ?) and you are pumping.
There is one in the Trader Section of Explor Oz now:18 months old. Hardly used.
Price: $250
State: NSW City:
Sydney Suburb: Pagewood
Name: Bart
Phone: xxxxxx
Submitted: 09 Oct 2003
Cheers,
Wazza
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Reply By: Tony - Wednesday, Nov 05, 2003 at 11:34
Wednesday, Nov 05, 2003 at 11:34
A mate of
mine had a 60 series with "no" room under the bonett, made up a removable bracket that held a A/C compresser and used a ockky strap to tension it, worked a treat, about 2 min to fit up and no time to pump up tyres at a fast idle.
The only other mod was a double pully to run the belt off.
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Reply By: Coops (Pilbara) - Wednesday, Nov 05, 2003 at 11:35
Wednesday, Nov 05, 2003 at 11:35
Gunzo
I too have 285/75R16's and face a similar problem. One way I counteract is to pump tyres temporarily to 25 psi (this is done rather quickly) and then make my way to the nearest servo at a leisurely pace. You would probably have more access to servos than I also and this might get you around the problem. Other than that I have friends who use a fitting on scuba cylinders, which works a treat too.Allyn
Where to next ?
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Reply By: chrisfrd - Wednesday, Nov 05, 2003 at 13:55
Wednesday, Nov 05, 2003 at 13:55
I have fitted an E-Air to an 80 series turbo-diesel for a club-mate of
mine.
We fabricated the brackets with a mate doing all the welding (electronics is my forte - not welding!) We removed the useless thermo-fan and fitted dual electric units (Davis-Craig) and re-engineered the whole belting system to attach the EA unit atop of the alternator, using an idle-pully and some tensioning points for two smaller belts to drive the alternator and EA unit.
All looks very nice, costed up to be around $300 in brackets, pully wheels, bearings and such.... And he is getting a 40L receiver made up that will bolt directly to the inside of the bullbar.
There's plenty of wasted space in those things. The thing I'm trying to get across is that there are many ways of skinning a cat, it's just a matter of practicing some basic engineering philosophies and making everything up to suit.
Personally, I would never carry cylinders and such, just because they are in the way, they are heavy, cumbersome and potentially stealable (if bolted to the spare wheel that is). KISS... That's the way.....
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Reply By: gunzo - Wednesday, Nov 05, 2003 at 23:37
Wednesday, Nov 05, 2003 at 23:37
Thanks for all the responses ,youve all talked me out of the inverter/240v compressor option.
Ive found the unit I think Ill go with from an old
forum posting, an Oasis 12v winchmotor connected to a auto air conditioner compressor (
york) and pumps a very respectable 9cfm @ 50psi (the 24v dose 17cfm @ 50psi) the amp draw however is 120 to 180 amps but as tyre inflation times will be dramaticaly reduced to less than 5 mins for all 4 tyres the load shouldnt be to much for the batery.
The unit costs around $1000 australian dollars. see
http://www.oasisoffroad.com/trailheadAirCompressor.html
and so far it is the only unit of its type ive been able to source (there in America)
I hope they can air freight me one , I called them this morning (in US) but there not available to contact till monday 10/11 (there at a trade show).
I called arb and opisite lock but they hadnt herd of this type of compressor
nor were they interested in helping me source one from Australia, dose anyone know of any retail
places in Australia who sell these powerful 12v compressors.?
Id rather buy in Australia if I could.
Also has anyone seen one of these things working? ,have a look at the site and tell me what you all think.
Thanks
scott
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Follow Up By: Member - Bob - Thursday, Nov 06, 2003 at 11:25
Thursday, Nov 06, 2003 at 11:25
Gunzo,
Fedex or Express Mail for something as heavy as a compressor is going to be a lot of dollars. Also allow for customs fees and GST ($50 plus 10% of invoice cost). I'd be very surprised if you landed it for less than $1200.Bob
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Follow Up By: Brimo - Saturday, Nov 08, 2003 at 16:38
Saturday, Nov 08, 2003 at 16:38
120-180 amps for 5 mins! hope you have a bloody good battery and be sure to use some monster size cables and good quality connectors on the thing if you want to avoid a melt down. A smaller compressor and a receiver would save you a heap of hassle.
Regards
Brimo {a sparky who knows a bit about electricity:-) }
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Reply By: Matt M - Thursday, Nov 06, 2003 at 18:12
Thursday, Nov 06, 2003 at 18:12
Sounds like alot of expense and alot of work, when a little petrol compressor would do the job nicely!!
Yeah they can be a little weightly but the most is the little briggs and stratton motor, the reservoir could even be mounted under the sill near the chassis rails and utilise a QD for the mounted motor and compressor? That way it could be semi mounted in the vehicle and removed when not needed. The air tanks could then also be fitted with a tyre valve fitting, so that they can be replenished when you can from a servo compressor, allowing a reserve supply on the vehicle even if the compressor isnt on board.
But it that is too much, fitting of one of the top heavy duty 12 pumps with the reservoirs mounted would allow for a large reserve capacity, this really being the problem with inflation times. Then the compressor, using a ARB cutout can just happily run away, topping up the tank when you are back on the road waiting for the next deflation/inflation!!
Its all about reserve capacity if the huge CFM pumps are out of the question, so look for tanks!!!!
Goodluck!
Matt.
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Reply By: Wazza (Vic) - Saturday, Nov 08, 2003 at 08:34