HI, ive done a stupid thing, i cut the alligater clamps off the 12 volt compressor wires to fit an anderson plug but i forgot which one is red and black. i have no tools or meters at the moment. ANY IDEAS please CHEERS FROM PETER.
KevinC said
05:00 PM Dec 21, 2020
I doubt there are too many electronic components in your compressor, so just connect it to 12v and see if it runs. Possibly run backwards or not at all if the polarity is wrong.
Tony LEE said
05:23 PM Dec 21, 2020
Usually the wires have a coloured stripe or raised ribs on one of the wires to denote which is which
Whenarewethere said
05:28 PM Dec 21, 2020
Just run it very briefly to see if you have a vacuum, or most likely no air at all.
While at it cut most of the wire off as the wires are too thinner gauge to start with.
If it's a decent compressor is will draw about 30amps.
What is the compressor's duty cycle? You don't want to cook it.
As a very rough guide you will loose about 1% of the compressor's capacity for every metre of power & air hose & every connector.
A useful guide for airflow at different pressure. Most manufacturers say litres at 0 psi (well actually 1 atmosphere) & maximum pressure at 0 litres, both useless statements. Ideally they should state SCFM Standard Cubic Feet per Minute. CFM is also a meaningless statement without an S in front.
Can you match the cutoff cable/alligator clamps to the remaining cable.
Maybe the shape or angle of cut may give you a clue.
Ken
cobberdog said
06:20 PM Dec 21, 2020
no stripe or raised on wires, i tried to match the cuts but they both seem pretty straight, it says 45 amps on the compressor, the wires are quite thick ( its an old THUMPER from supa center ) i just put it to an old battery in the garage turned it on but the both wires got very hot after about 10 seconds so i turned it off.
landy said
10:02 PM Dec 21, 2020
Not sure if this will work or not but it might be worth a try, see if either wire has continuity back to the compressor's frame with your multi meter. if you have continuity on just one wire it is probably negative.
dorian said
05:45 AM Dec 22, 2020
I can't believe the "suck it and see" responses in this thread. If the compressor's polarity doesn't matter, then why are the wires colour coded?
I would do what "landy" suggests. Alternatively, if the compressor has a fuse, test for continuity with the positive lead.
outlaw40 said
06:21 AM Dec 22, 2020
dorian wrote:
I can't believe the "suck it and see" responses in this thread. If the compressor's polarity doesn't matter,then why are the wires colour coded?
I would do what "landy" suggests. Alternatively, if the compressor has a fuse, test for continuity with the positive lead.
they aren't that's cobberdogs problem .
Whenarewethere said
06:27 AM Dec 22, 2020
If it's an old compressor the cylinder has probably corroded from water. When you compress air, let's say typically 90psi, you end up with 6 times the water content in the air. Most of which will end up in the tyre & the remainder in gaps in the cylinder & then it will corroded over time.
outlaw40 said
07:41 AM Dec 22, 2020
At the end of the day its only a DC motor isn't it ... " Simply put, DC motors can turn in either direction (clockwise or counter-clockwise) and can be easily controlled by inverting the polarity of the applied voltage. Strictly speaking, the motors can actually create a force in either direction " the only stipulation i would give is when turned on if its not blowing air dont let it keep running as the compressor head would not be set up to SUCK air so continued running may damage it , a short burst to determine if its blowing air wont hurt it .
-- Edited by outlaw40 on Tuesday 22nd of December 2020 07:45:46 AM
Whenarewethere said
08:00 AM Dec 22, 2020
A couple of seconds either way won't hurt. People put the wrong clamp on the wrong terminal all the time. Even I have done it! That's why I like Anderson plugs.
You are more than likely to get no air with polarity the wrong way as that is how the valve is set up. It's a simple flap so air can't go backwards.
If the motor is stalled, don't keep trying. Put the thing apart. My ARB compressors you can pull them apart & buy new parts, although in the long run probably not worth it.
travellinglew said
08:26 AM Dec 22, 2020
It is a simple DC motor and will work on either polarity as reversing the polarity is how a DC motor direction is controlled. As for the pump side of it, the motion on the pump is a simple in and out and again motion. (up and down if you prefer) It will pump air no matter what direction the motor is spinning. I would be surprised if their is any electronics within the pump that would be upset by the direction of the current. A search online for the pump diag. may help
Lew
Dougwe said
12:25 PM Dec 22, 2020
cobberdog wrote:
HI, ive done a stupid thing, i cut the alligater clamps off the 12 volt compressor wires to fit an anderson plug but i forgot which one is red and black. i have no tools or meters at the moment. ANY IDEAS please CHEERS FROM PETER.
I did the same with my TJM pump and fitted to Anderson plug and found it works even better with car running. I don't think it's the best of pumps though.
Luckily I noticed no + or - markings on wires so marked + before cutting. Worked well.
cobberdog said
12:29 PM Dec 22, 2020
thanks every-one, after running a few seconds on a battery out of my 4wd, the wires got hot so i reversed them and tried again and the wires didnt get hot , so i assumed this may be the correct way around. ive put an anderson plug on and plugged it into the dual battery , IT RUNS , hope it works out in the bush inflating 4wd tyres. thanks again . Peter.
Moose2 said
12:59 PM Dec 22, 2020
Whenarewethere wrote:
If it's an old compressor the cylinder has probably corroded from water. When you compress air, let's say typically 90psi, you end up with 6 times the water content in the air. Most of which will end up in the tyre & the remainder in gaps in the cylinder & then it will corroded over time.
So is there a solution to stop this happening?
Whenarewethere said
03:11 PM Dec 22, 2020
Yes, & it is not difficult.
An air tank will remove some moisture if the tank is cold, only for the first few minutes, water will condense on the tank walls, but only some. If you can't mount the tank on end for easy draining make it removable, or get a block welded on the bottom to install a drain valve, quite a few do this.
The hoses all unclip on my setup & all the compressors are on quick release brackets for maintenance.
The only thing I haven't put in yet is a desiccant dryer, working on that one (refrigerator dryers are too large), which would be mounted after the moisture trap.
Find out the duty cycle of your compressor, & half the time so the compressor lives longer. Manufacturers are too optimistic.
Moisture trap. I have replaced the ARB connectors with Euro connectors & all the blue hose is rubber inside, 8 or 10mm ID, orange ARB hose is 7mm ID.
Moisture after one tyre on a humid day.
Air tank can easily be removed to drain.
Heat sinks to reduce temperature at the most effective point, when it's hot straight out of the compressor, also fan cooled. The hose connector at a compressor will get dangerously hot, I can actually hold mine without burning myself.
Internal heat sink. The cooler you can get the air the less moisture the air can hold, so more water is condensed. The water trap can only remove condensed water.
After cooler, which goes before the moisture trap, preferably before the air tank. You could even stick it in a bucket of water for better cooling, or fan cooled.
HI, ive done a stupid thing, i cut the alligater clamps off the 12 volt compressor wires to fit an anderson plug but i forgot which one is red and black. i have no tools or meters at the moment. ANY IDEAS please CHEERS FROM PETER.
Just run it very briefly to see if you have a vacuum, or most likely no air at all.
While at it cut most of the wire off as the wires are too thinner gauge to start with.
If it's a decent compressor is will draw about 30amps.
What is the compressor's duty cycle? You don't want to cook it.
As a very rough guide you will loose about 1% of the compressor's capacity for every metre of power & air hose & every connector.
A useful guide for airflow at different pressure. Most manufacturers say litres at 0 psi (well actually 1 atmosphere) & maximum pressure at 0 litres, both useless statements. Ideally they should state SCFM Standard Cubic Feet per Minute. CFM is also a meaningless statement without an S in front.
Maybe the shape or angle of cut may give you a clue.
Ken
I would do what "landy" suggests. Alternatively, if the compressor has a fuse, test for continuity with the positive lead.
they aren't that's cobberdogs problem .
If it's an old compressor the cylinder has probably corroded from water. When you compress air, let's say typically 90psi, you end up with 6 times the water content in the air. Most of which will end up in the tyre & the remainder in gaps in the cylinder & then it will corroded over time.
At the end of the day its only a DC motor isn't it ...
" Simply put, DC motors can turn in either direction (clockwise or counter-clockwise) and can be easily controlled by inverting the polarity of the applied voltage. Strictly speaking, the motors can actually create a force in either direction " the only stipulation i would give is when turned on if its not blowing air dont let it keep running as the compressor head would not be set up to SUCK air so continued running may damage it , a short burst to determine if its blowing air wont hurt it .
-- Edited by outlaw40 on Tuesday 22nd of December 2020 07:45:46 AM
A couple of seconds either way won't hurt. People put the wrong clamp on the wrong terminal all the time. Even I have done it! That's why I like Anderson plugs.
You are more than likely to get no air with polarity the wrong way as that is how the valve is set up. It's a simple flap so air can't go backwards.
If the motor is stalled, don't keep trying. Put the thing apart. My ARB compressors you can pull them apart & buy new parts, although in the long run probably not worth it.
Lew
I did the same with my TJM pump and fitted to Anderson plug and found it works even better with car running. I don't think it's the best of pumps though.
Luckily I noticed no + or - markings on wires so marked + before cutting. Worked well.
So is there a solution to stop this happening?
Yes, & it is not difficult.
An air tank will remove some moisture if the tank is cold, only for the first few minutes, water will condense on the tank walls, but only some. If you can't mount the tank on end for easy draining make it removable, or get a block welded on the bottom to install a drain valve, quite a few do this.
The hoses all unclip on my setup & all the compressors are on quick release brackets for maintenance.
The only thing I haven't put in yet is a desiccant dryer, working on that one (refrigerator dryers are too large), which would be mounted after the moisture trap.
Find out the duty cycle of your compressor, & half the time so the compressor lives longer. Manufacturers are too optimistic.
Moisture trap. I have replaced the ARB connectors with Euro connectors & all the blue hose is rubber inside, 8 or 10mm ID, orange ARB hose is 7mm ID.
Moisture after one tyre on a humid day.
Air tank can easily be removed to drain.
Heat sinks to reduce temperature at the most effective point, when it's hot straight out of the compressor, also fan cooled. The hose connector at a compressor will get dangerously hot, I can actually hold mine without burning myself.
Internal heat sink. The cooler you can get the air the less moisture the air can hold, so more water is condensed. The water trap can only remove condensed water.
After cooler, which goes before the moisture trap, preferably before the air tank. You could even stick it in a bucket of water for better cooling, or fan cooled.