Strange electrical question...

A friend of mine procured an air-compressor from a piece of medical equipment (he's in the business). This is a 110V compressor.

How do we install this in his J10 to produce on-board air?

Is there some kind of 12V to 120V transformer? Can I get it at Radio Shack?

I am asking, because if I can help him to get it working, he'll give me one for my XJ...

any decent electronics store will have an automotive power invertor that converts 12vdc to 120vac, just make sure you get one for the appropriate wattage.

I guess I am looking for something that I can have hardwired, full time. I have seen a lot of inverters that you plug into the dash hole, or clip onto the battery terminals.. They all have receptacle oriented power distribution.

Has anyone seen an inverter that can take a wire nut..? We wanna mount a switch on the dash...

The only thing stopping you from making a plug in one work is a little wire a spst relay a switch and a fuse. There is no reason the higher rated inverters will not work but I can tell you right now that one that plugs in to your lighter socket is not big enough. You can get these from any auto parts store but remember you get what you pay for. If you do not now how to wire it I would be glad to go over it with you. Let me Know.

Joe

Do you have any suggestions for an adequate inverter..?

http://www.donrowe.com/inverters/xpower_small.html

I will be calling on your knowledge once this moves out of conception mode.. Thanks

Home Depot carries power inverters...they can get them any size you want. The only problem is...the inverter will cost more than a good 12VDC compressor if you need over 600 watts...at 120 volts thats only 5 amps. The compressor should be tagged with current consumption info...either MCA amperage (minimum circuit ampacity) or the rated amp draw (remember that when the compressor starts under load it will momentarily need at least an additional 40% more current than the rated amp draw) the other info may be wattage consumption Eg: 1200W. To figure amperage draw divide wattage by voltage...the same 40% rule applies during start up under load.

Hope this helps. Dawg

xjwoody said:

Do you have any suggestions for an adequate inverter..?

http://www.donrowe.com/inverters/xpower_small.html

I will be calling on your knowledge once this moves out of conception mode.. Thanks

Click to expand...

you need to give us the specs (power consumption) on that compressor first.
basically, how many amps or watts does it draw (max)? this will be for 120 VAC obviously.

once you have this number, THEN you can begin to choose which inverter you want to buy.
i believe you made mention of a "wire nut" earlier. i really hope you dont use wire nuts for your automotive wiring connections. they are really meant for household light duty purposes only. (even then i stay away from them when i can)
do yourself a favor and go out and get a (even from radio shack if u like it there) wire cutter/stripper/crimper tool and a box of el cheapo crimp connectors--even THOSE will be 100% better than (GASP) wire nuts.
if you want to do it right, be sure to go with proper gauge wire for the install job and use crimp and HEATSHRINK electrical connections.
let us know how much juice this thing sucks, and we'll help you choose an inverter and proper wire to install it.

if you have any questions, please ask.


CaptTrev

Xjwoody, I’m running a 1,000 watt continuous/ 2,000 watt peak inverter in the cargo area of my XJ. It runs a ½” drill and a 5 hp/30gal air compressor without any problems, I’m assuming that’s the type of power you are wanting. I did the whole thing on the cheap; inverter was $70 at Sam’s and used a set of jumper cables (4 ga wire) to wire it directly off of the battery. Look at the ratings on the inverters very carefully; they should have a continuous and peak rating. What most places sell as a 1,000 watt inverter is actually 500 watt continious/1,000 watt peak. Large electrical motors (like drills, compressors, etc) take a lot of juice initially to get started and need a large buffer. BTW my system is fine for electrical motor driven stuff, but its not “clean” enough for computers and such. The nice modified sine wave stuff is really expensive. I haven’t figured out how to post pictures here yet, PM me with an email address if you want to see the install.

Yeah - most inverters carry two ratings - surge and continuous. I have a 800/400W hardwired in on the right side of the transmission hump on my 88 - it doesn't run a great deal of stuff (I'll sort that out later) but it does come in handy on long road trips.

A note on inverters - check the lit to make sure it doesn't have any trouble with a purely inductive load! If it is mentioned, make sure to have a small resistive load (like a low-watt light bulb) to plug in at the same time. Motors are inductive loads, and some inverters don't like the feedback that results from a running motor - be warned.

So, you will need to know nominal current draw at startup, nominal current draw while running, and volts * amps = watts. If power specs are listed in watts, you've already got the numbers you need.

Got any more of those little compressors? I could use one or two if I could get my ratty little paws on them...

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