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12v Compressor into 12v socket

Posted: Wed May 04, 2005 10:41 am
by Mick G
Just bought a new Bushman Max Air compressor and am wondering if there are any down sides to replacing the 2 battery clips with a cigarette socket connector and then obviously plugging that into a socket in the rear?

Cheers

Posted: Wed May 04, 2005 11:22 am
by Tas_Dean
How much current does the compressor pull? It SHOULD have a rating plate on it. Remember that a cigarette lighter socket is rated only to ten amps (and in reality most aren't good for that!), and if it's a factory plug in the rear then it's probably only got very small wiring.
You can get better accessory sockets than lighter sockets, that give a reliable connection (and they will mount in place of a lighter plug!)

Cheers, Dean

wire

Posted: Wed May 04, 2005 11:44 am
by Toy80Diesel
I wouldn't trust that socket to have the amps you need.

Install a wire from the battery, fused at the battery, similar to the wire people install for amplifiers in their cars. Use something of decent amp carrying capacity and then fit a socket in the rear, maybe even one of those similar to cigarette lighter ones, its smaller but handles more amps.

You wont regret doing this, it will come in handy if you get a fridge that needs direct power. (i.e. without ignition) or a higher powered sound system.

Re: wire

Posted: Wed May 04, 2005 12:55 pm
by Tiny
Toy80Diesel wrote:I wouldn't trust that socket to have the amps you need.

Install a wire from the battery, fused at the battery, similar to the wire people install for amplifiers in their cars. Use something of decent amp carrying capacity and then fit a socket in the rear, maybe even one of those similar to cigarette lighter ones, its smaller but handles more amps.

You wont regret doing this, it will come in handy if you get a fridge that needs direct power. (i.e. without ignition) or a higher powered sound system.


have seen plugs melt and burn out from running a fridge, low current draw......if you dont want lift the bonnet everytime, run decent wire to one of those round earth 240v socket, and rewire the comp with the other end of them

wire earth to the neg on 240v and active to the 240v earth

Posted: Wed May 04, 2005 1:07 pm
by -Scott-
Your average cigarette lighter socket can't handle a 100W spotlight for extended periods, and I expect an air compressor to pull significantly more current.

Cheers,

Scott

Re: wire

Posted: Wed May 04, 2005 1:11 pm
by -Scott-
Tiny wrote:
Toy80Diesel wrote:I wouldn't trust that socket to have the amps you need.

Install a wire from the battery, fused at the battery, similar to the wire people install for amplifiers in their cars. Use something of decent amp carrying capacity and then fit a socket in the rear, maybe even one of those similar to cigarette lighter ones, its smaller but handles more amps.

You wont regret doing this, it will come in handy if you get a fridge that needs direct power. (i.e. without ignition) or a higher powered sound system.


have seen plugs melt and burn out from running a fridge, low current draw......if you dont want lift the bonnet everytime, run decent wire to one of those round earth 240v socket, and rewire the comp with the other end of them

wire earth to the neg on 240v and active to the 240v earth


DO NOT use 240V mains plugs and sockets for 12V.

I know Tiny wasn't saying this, but I think it needs to be made crystal clear. There is a similar style of plug and socket available for low voltage DC applications - I'm not sure where you get them, but they would be suitable for your compressor.

Some other alternatives are Anderson plugs (common in the caravanning world, I think some are rated in excess of 50 Amps) or Hella make something similar to a cigarette plug which is supposed to be more reliable.

Cheers,

Scott

Re: wire

Posted: Wed May 04, 2005 8:50 pm
by Rainbow Warrior
NJ SWB wrote:
DO NOT use 240V mains plugs and sockets for 12V.

I know Tiny wasn't saying this, but I think it needs to be made crystal clear. There is a similar style of plug and socket available for low voltage DC applications - I'm not sure where you get them, but they would be suitable for your compressor.

Cheers,
Scott


The reasoning behind this is someone may get a nasty surprise when they plug the 3 pin plug hanging out of your Chescold or Waeco into the 240v outlet in the garage.

Most 240v stuff won't give a stuff if plugged into 12v
This is the reason Tiny was using a round earthpin plug I suspect, though they are no easier to buy than the proper 12v article.

Posted: Wed May 04, 2005 9:18 pm
by mickyd555
240 V gear is designed to be used for AC switching, 12V car electrics is DC. the switch gap needs to be larger in DC than AC, therefore, using 240 V rated stuff in ya car is not gonna do you any good at all. use the proper gear or youll find it will fail you at the wrong time

Posted: Thu May 05, 2005 5:35 am
by Rainbow Warrior
mickyd555 wrote:240 V gear is designed to be used for AC switching, 12V car electrics is DC. the switch gap needs to be larger in DC than AC, therefore, using 240 V rated stuff in ya car is not gonna do you any good at all. use the proper gear or youll find it will fail you at the wrong time


Depends a bit on what your load is really, I've used 240v switches quite often and only had one occasion where the contacts welded on and that was pretty close to the max ampage of the switch rating.

I've had my 1700w inverter isolated through a parralleled 55A 3 phase isolator for 3 years now, no problem, it can pull up to 200A on full load, but would never be switched at that ampage of course. It's plugged in by a 32A 3 phase plug too, with no meltdown.

Re: wire

Posted: Thu May 05, 2005 8:42 am
by Tiny
NJ SWB wrote:
Tiny wrote:
Toy80Diesel wrote:I wouldn't trust that socket to have the amps you need.

Install a wire from the battery, fused at the battery, similar to the wire people install for amplifiers in their cars. Use something of decent amp carrying capacity and then fit a socket in the rear, maybe even one of those similar to cigarette lighter ones, its smaller but handles more amps.

You wont regret doing this, it will come in handy if you get a fridge that needs direct power. (i.e. without ignition) or a higher powered sound system.


have seen plugs melt and burn out from running a fridge, low current draw......if you dont want lift the bonnet everytime, run decent wire to one of those round earth 240v socket, and rewire the comp with the other end of them

wire earth to the neg on 240v and active to the 240v earth


DO NOT use 240V mains plugs and sockets for 12V.

I know Tiny wasn't saying this, but I think it needs to be made crystal clear. There is a similar style of plug and socket available for low voltage DC applications - I'm not sure where you get them, but they would be suitable for your compressor.

Some other alternatives are Anderson plugs (common in the caravanning world, I think some are rated in excess of 50 Amps) or Hella make something similar to a cigarette plug which is supposed to be more reliable.

Cheers,

Scott


sorry, should explain myself better, as ya say, they are "similar" to a 240v socket, and are not :lol: :lol:


the point is that there are many options to run your comperssor, but a ciggie plug is not one of them

Posted: Thu May 05, 2005 9:38 am
by Mick G
Cheers for the input guys. A direct and decent connection to the second battery is in order.

Mick