Compressor and tank install - solenoid or relay?

[gtir300]

Finally got round to installing hard wiring in my Boss Air Compressor and Air tank, but I am stumped on the use of a metal bodied solenoid!

I bought the whole lot as a kit 18months ago, the solenoid supplied is suppose to be 100amp continuous duty - HOWEVER it only has one trigger point on the solenoid (think it may be a intermitterent type)

It is wired up to my custom rear fuse panel (supplied with fused battery cable from 2nd battery to rear of car).

I have a +12v ign supply through a dash mounted switch, this then runs through the air tank pressure switch and to solenoid.

Now the solenoid switches on, but when I turn off the dashboard switch, the compressor continues to run

From searching, I believe that the solenoid is actually an intermittment type (switches off after set time)

I have fitted a 150psi pressure relief valve, but want to put a pressure gauge in as a visual check - I therefore did not allow the compressor to run too long until I put the gauge in!

Am I right that this solenoid is an intermittent type??

If I use a continuous solenoid, I assume I need to have two +12V triggers (one to each trigger pole) to throw the solenoid in and out - is this correct??

OR

could I use a Narva 70amp (or 100amp) conventional 4pin relay instead (i prefer these over the solenoids!)??
If I use this, then I assume I can use one +12v ign switching supply and normal rocker switch?

What do you people think?

[beretta]

Good questin as I am about to install one of these. Got a pic or diagram of how you've wired it.

[Cossie]

The fuse near the battery is to protect your wiring and should be a suitable rating for your compressor. The fuse in the ignition supply line may not be necessary if its already a fused circuit, otherwise only needs to be 10amp max. The ignition supply wire doesn't need to be big, the compressor one does and needs to be suitable for your chosen compressor. A 40amp relay would probably suffice, I'd be surprised if the compressor is drawing more than that.

[-Scott-]

The fuse near the battery is to protect your wiring and should be a suitable rating for your compressor. The fuse in the ignition supply line may not be necessary if its already a fused circuit, otherwise only needs to be 10amp max. The ignition supply wire doesn't need to be big, the compressor one does and needs to be suitable for your chosen compressor. A 40amp relay would probably suffice, I'd be surprised if the compressor is drawing more than that.

Wot he sed will work well, but I'm obsessive-compulsive. If you don't add your own fuse to your switch circuit a short circuit in your relay supply wiring could cause you to lose power to more than just your compressor (depending on which circuit you tap into.) If you add a second fuse (smaller than the one already there) any fault in the relay wiring should only isolate the relay.

Not a huge issue, but something to consider.

[Bluey]

funny, i had the same problem with the solenoid that comes with the boss compressor system. i just figured it was a dodgey solenoid so i replaced it after it would turn off when i wanted it to

might need to investigate further

[gtir300]

I sent BOSS a query, they responded with this:

the black cable from the compressor goes straight to the big terminal on the solenoid (doesn't matter which one so long as its a big one), the other big one goes straight to earth. take a wire from your ignition (or a switch) to the pressure switch then to the small terminal on the solenoid. Make sure the solenoid is earthed.
We do not recommend having the compressor portable because of the high amp draw you could damage it unless you run large 4 gauge cable (approx 15mm) we suggest it is fixed in the vehicle. You will notice we use the earth cable as the way to turn it on, NOT the + cable as this must run straight to the compressor via whatever 80 or 100amp fuse you choose to use,this is to help prevent more power loss to the compressor.

I need to have a good look at it agian, but can see the above working. I'll let you know how I get on.

[Cossie]

You will notice we use the earth cable as the way to turn it on, NOT the + cable as this must run straight to the compressor via whatever 80 or 100amp fuse you choose to use,this is to help prevent more power loss to the compressor.

What a crock of shit!

[Bluey]

You will notice we use the earth cable as the way to turn it on, NOT the + cable as this must run straight to the compressor via whatever 80 or 100amp fuse you choose to use,this is to help prevent more power loss to the compressor.

What a crock of shit!

what he said

the only reason for this would be extremely bad contacts in the solenoid with excissive resistance. this would also mean the solenoid is most likely not working at all. as for 80-100 amp fuse, christ are they recommending a setup to burn cars down. the rating on the comp says something like 25A on startup, i use a 30A fuse

[gtir300]

well i tried it (all circuits safely fused) and it doesnt work surprise surprise It didn't feel right anyway doing it that way!

I have only ever used a 40 circuit breaker (manual reset) with 6mm auto cable and had the compressor in a make shift toolbox so it was portable....never had any troubles.

When I bought it it said 35amp breaker/fuse, I have noticed that they are now recommending a 100amp.................load of old toffee, would never put that in for a compressor!

After popping a 10amp fuse or two I ripped the solenoid out and temp wired a 40amp 4 pin relay in the usual way......it worked exactly as I wanted

Will buy a 70amp 4pin relay and swap over and tidy up all wiring at the weekend and finish the install.

[Hobzee]

Glad you got it sorted..

I was just alerted to this thread and could have solved a lot of questions earlier - apologies for not knowing about this.

None of the BOSS supplied solenoids are on timers nor do they need to be turned off. They are heavy duty on/off solenoids where by a trigger power turns them on and when the trigger supply is cut they then turn off. They are spring loaded and need the trigger current to fight against the spring to keep the main heavy circuit flowing. If it does not turn off then it is either not wired right in the first place and would have been on all the time to start with or the solenoid is faulty. I had my first faulty one reported to me only a week ago and we agreed to replace it free of charge. Haven't yet seen the faulty item so not yet even 100% convinced of the fault.

It worries me in general that not enough power gets to the compressors. I have plenty of pepole say they run extremely heavy wires and when I have a sneak peek at a Navrun or similar opportunity I see wire that is about 20% of what it should be. I am speaking very heavy welding or battery cable and then the compressors rock.

If any one continues to have solenoid concerns, please give me a PM or call on 0417 486 637 an I can explain how the solenoids ought to work.

Hobzee