Wiring up my BIG PUMP compressor

Post by **vanbox** » Thu May 10, 2007 5:29 pm

i have just taken delivery of my new BIG PUMP PX07 compressor from pro bag. and i have to say

ITS HUGE.

the only concern and question i have is this.

it states in the wiring setup to run 15mm cable through a 100A fuse. the compressor draws at max approx 60A on startup. is that size cable overkill? (compressor will be behind seats of a GU cab chassis, distance approx 2m max)

where abouts would i have the switch to turn it on and off?

the scary thing is though, the compressor has a + and - lead out of it, now they are only approx 5mm in diameter. the instructions say to connect the 15mm cable direct to the 5mm.

is that right???

thanks

PAUL

p.s thought it would be better here than auto elec. more opinions

Post by **mickyd555** » Thu May 10, 2007 5:38 pm

got any pics of this thing?? it sounds like overkill but if its that big it might be a good idea?

Post by **vanbox** » Thu May 10, 2007 5:40 pm

just edited it then.

cheers

PAUL

Post by **mickyd555** » Thu May 10, 2007 5:44 pm

take a pic of that silver label on the top of the pump.

Post by **vanbox** » Thu May 10, 2007 5:48 pm

Post by **gtir300** » Thu May 10, 2007 5:55 pm

I have this compressor that I bought off Hobzee (his Ebay store) its 3/4hp and 3cfm isn't it?????

cant be right on the 15mm cable, as you say the pump fly leads are only 5mm. That said cable size will depend on voltage drop (linked to length of cable!)

After 9months I still have this compressor in a plastic toolbox with twin 6mm cables approx 1.4m long, i then alligator clip to the battery put compressor in front of truck and run a 10mm blue nylon airline to all 4 tyres. Its still quick in this guise but i will fit up in the engine bay with air tank alongside the chassis soon.

I used a resettable circuit breaker (40amp i think) as the compressor pulls 30-35amp on startup.......looks like they have changed their specs tho, i will check mine tonight.

Post by **gtir300** » Thu May 10, 2007 5:58 pm

Check this link

http://www.users.bigpond.net.au/rta8925 ... essors.htm

thats the spec for your compressor! May be worth a phone call to Pro-bag to confirm! (and reprot here

)

Post by **vanbox** » Thu May 10, 2007 6:40 pm

looks like they have changed their specs tho, i will check mine tonight.

gtir300 that would be good thanks.

how much was the circuit breaker? might be a better option then fuses = $$$$ can u get 12v ones? from supercheap or something else?

a call to probag will be the safest option though. so will prob do it tomorrow without some more opinions from here.

Post by **360 scout** » Thu May 10, 2007 7:54 pm

I've been running one of these compressors for about 12 months just run 5mm cable to the relay doesn't get hot & no trouble on start up .

Post by **nicbeer** » Thu May 10, 2007 8:00 pm

maybe 15 amp cable not 15mm ??

Post by **vanbox** » Thu May 10, 2007 8:01 pm

are u using a relay? (30A) or a heavy duty solenoid like the diagram shows?

ill ring probag to confirm, but everyone so far seems to think the requirements are overkill. ESPECIALLY because the fly wires from the comp are tiny (5mm).

where abouts in that wiring diagram would the on/off switch be? in the power supply TO the pressure switch?

Post by **vanbox** » Thu May 10, 2007 8:02 pm

maybe 15 amp cable not 15mm ??

good thought, but i imagine it would need to be more than 15Amp. however 15mm cable should be good for several hundred amps

Post by **Shadow** » Thu May 10, 2007 9:33 pm

vanbox wrote:
maybe 15 amp cable not 15mm ??
good thought, but i imagine it would need to be more than 15Amp. however 15mm cable should be good for several hundred amps

it probably means 15mm squared, as in the cross sectional area of the cable.

that would make the cable with a copper diameter of 4.4mm, overall diameter(including shielding) about 7mm

Post by **vanbox** » Thu May 10, 2007 9:45 pm

it probably means 15mm squared, as in the cross sectional area of the cable.

that would make the cable with a copper diameter of 4.4mm, overall diameter(including shielding) about 7mm

thats the most logical explanation so far. thats the approx size of the wires from the compressor.

that sort of gauge wire wont be able to carry 100A would it? cause thats the fuse they recommend. ill get a circuit breaker though.

Thu May 10, 2007 9:50 pm

you would want a wire that can carry atleast 60 amp continuous and able to handle 100 amp peak

Post by **bigcam** » Thu May 10, 2007 9:51 pm

shadow bet me to it its 15mm^2.

cross sectional area, go to jaycar and get cable rated to 80 amp or so shoudl be sweet (8 guage would be plenty)

Post by **Shadow** » Thu May 10, 2007 9:55 pm

vanbox wrote:
it probably means 15mm squared, as in the cross sectional area of the cable.

that would make the cable with a copper diameter of 4.4mm, overall diameter(including shielding) about 7mm
thats the most logical explanation so far. thats the approx size of the wires from the compressor.

that sort of gauge wire wont be able to carry 100A would it? cause thats the fuse they recommend. ill get a circuit breaker though.

100amp fuse doesnt mean the compressor will draw 100amp continuous.

It only draws an 80amp kick at the start, and then settles to probably about 30amps running.

Thus, the cable doesnt need to be rated to 80amps at all, rather, a 40/50amp cable would be enough.

A 2 amp cable can carry 80amps, just not for very long.

Post by **vanbox** » Fri May 11, 2007 7:03 am

alright sounding good now.

would i still use a 100A circuit breaker like they recommend? and if possible ill try and get some 80A wire to cover the initial "kick" of 60A.

what size relay should i use? they list a solenoid but now i know it doesnt need to be that heavy. do they make relays of 80A or so?

my question about the fuse and wire is that if the fuse is rated higher then the cable, wont it melt before the fuse goes?

Post by **maverick01** » Fri May 11, 2007 8:57 am

i have just fitted a big red compressor in the stoage system of my patrol SWB and between the pump and the air tank i would recommend using braided line or stainless line as i keep melting the standard air line most shops will say to use. Mkae sure the compressor gets a good air flow as these type of pumps get hot quickly.

Post by **Shadow** » Fri May 11, 2007 9:18 am

vanbox wrote:alright sounding good now.

would i still use a 100A circuit breaker like they recommend? and if possible ill try and get some 80A wire to cover the initial "kick" of 60A.

what size relay should i use? they list a solenoid but now i know it doesnt need to be that heavy. do they make relays of 80A or so?

my question about the fuse and wire is that if the fuse is rated higher then the cable, wont it melt before the fuse goes?

well your fuse is designed to protect the cable and car from fire.

so if your going to use a 100amp fuse, you really should have 100 amp cable.

The alternative is, if you have 40amp cable, run a 40amp slow blow fuse. This will allow the pump to pull brief surges of much higher amperage, but will still protect your cable (and car) from fire.

Dont know if they make a "slow blow circuit breaker".

That said, i know in House applications, they use cable much the same for the mains supply to the house, which is rated at upwards of 80amps, so i think 15mm^2 cable is probably rated as high as 80 amps if not 100amps anyway.

Post by **Shadow** » Fri May 11, 2007 9:21 am

http://www.energy-solutions.co.uk/cable_conductor.html

This table indicates youd need 50mm^2 cable to carry 105amps at 60degrees C. now 50mm^2 cable is a diametre of 8mm (conductor) so probably about 12mm with shielding.

Post by **Shadow** » Fri May 11, 2007 9:25 am

if it was me, i would be using bigger cable since your running it into the vehicle and quite far (if its going behind the rear seats, id suggest it would be closer to 3metres or more).

Id grab some 50mm^2 cable, you might aswell do it right the first time.

even if it is overkill, you can then comfortably plug in other accessories back there, like fridge or lights etc.

http://www.powerstream.com/Wire_Size.htm

this site suggests youd need something witha diametre of 7.4mm 1guage, or 43mm^2.

Post by **... rick** » Fri May 11, 2007 2:35 pm

If it were me wiring this up in my car after spending $xxx on it, I would be following the directions to a tee to avoid any future possible warranty claims/disputes.

Post by **gtir300** » Sat May 12, 2007 1:18 pm

Sorry for delay in replying vanbox, the sticker on my compressor says 35amp circuit breaker (same as the link i posted to boss air suspension!!)

I bought the circuit breaker from an auto electrical wholesalers, it wasn't much I think $20 easily covered it!

Post by **ausoops** » Sat May 12, 2007 2:45 pm

dont even think about using 50mm2 for an air compressor, some winches don't even need 50mm2.
just use some 6mm2, 60A is maximum draw for the motor under locked rotor about 1/2 second if that, the running current would be no more than 75% of that. by all means use a large circuit breaker or fuse. with auto wiring the cb/fuse is only going to protect the cables from a short circuit not from overload. if your compressor is not going to be mounted in the engine bay then start thinking about bigger cable purely for voltage drop.

Sat May 12, 2007 5:27 pm

as for a relay what about a super crap dual battery solinoid it may be ok for that application

Post by **vanbox** » Sat May 12, 2007 6:04 pm

thanks for all the info guys. bought some gear today.

went with 4G wire rated to 120A to cover the 2m from engine bay to cab (i have a ute) so wont drop much voltage.

got me a 100A circuit breaker in place of a fuse (fuse and holder was same price) and a 200A dual battery solenoid to kick it into life.

havent wired it all up yet, just mounted the compressor today. waiting on all the air fittings to complete it.

thanks again for all your help.

PAUL

Post by **MUSS** » Sat May 12, 2007 6:06 pm

paul if you could mate keep this thred updated as i too have the same pump and am really keen to see other set ups...... more pics the better

Post by **vanbox** » Sat May 12, 2007 6:10 pm

yeh no probs. when its all finished ill have diagrams and pics for everyone. its costing me a bit just to wire it up, but im sure it will be worth it. got a BIG handful of air fittings on order and should be able to plumb it all next week sometime. cant wait!

PAUL

oh, does anyone know what the recommended air pressure to operate ARB lockers is? is there a safe range?

Post by **Shadow** » Sat May 12, 2007 6:45 pm

vanbox wrote:yeh no probs. when its all finished ill have diagrams and pics for everyone. its costing me a bit just to wire it up, but im sure it will be worth it. got a BIG handful of air fittings on order and should be able to plumb it all next week sometime. cant wait!

PAUL

oh, does anyone know what the recommended air pressure to operate ARB lockers is? is there a safe range?

85psi from what ive read on these forums.

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Wiring up my BIG PUMP compressor

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