What is the 20A pressure switch for in this diagram…is this different than the pressure switch on the tank? Does it have to be used?
http://static.hornblasters.org/diagrams/dgm-viair_dual_packs.pdf
That is the pressure switch on the tank.
so will my Viair 165-200 Pressure Switch w/ Relay be ok in this setup?
Are you running dual 480Cs like in the diagram?
If yes, just make sure that the relay is rated high enough for both.
Or you need 2 relays.
And yes, 165-200 is what’s listed in the chart.
yeah i just bought another 480c so ill have duals, and i was planning on doing 2 40A relays before the pressure switch…that should work…right?
Yep, I just looked at the diagram again.
You need 2 - 40 amp relays.
Sounds like you got a handle on it - good luck.
Whats a good guage wire to use for my main power to the compressor? What other size should i use for the rest?
4 GA - hasn’t failed me or anyone I’ve given tech support to yet…
holy crap 4 guage! how am i suppose to get a 4 guage wire hooked up to a 40amp relay?! Is there a smaller guage that will work or could i run two seperate power wires to each of the relays? how big of a wire would i have to go then?
This is geared towards the audio crowd, but amps is amps…
There is a chart based on load & length…should get you close.
http://www.knukonceptz.com/assets/pdf/PowerWireSpec.pdf
A suggestion would be to run 4ga to a distibution block and split into 2 - 8ga.
i dont need 8 ga wire for the rest of the wires of the relay that go to the pressure switch or compressor right?
That’s correct. You can use 14 or 16ga ‘primary’ wire from the hardware store.
thank you for all your help!
No problem
This is the only part of my own install that is actually started…lol
well it sure is a pain in the @$$. It starts to get fun when it comes to the horns tho.
Another note-
A safe & common practice is to fuse the 4ga as close to the battery as possible (within reason). A 100amp fuse would be plenty in your case, but this could be up to 150amp for 4ga cable. This fuse protects the WIRE between the battery & the D-Block in case of a short.
Then use a fused D-Block with appropriate fuses for each relay/compressor - usually slightly less than the rating of the relay & slightly more than the max draw of the compressor.
If you’re using 4ga, it helps to add a 4ga ground from your battery to the chassis. The stock negative battery cable is probably 8 or 6ga. Good luck to ya.
Yeah I have a pile-o-parts in my living room. K5LA no less…
I need to get out to the garage and test that baby out.
Maybe that’ll get me motivated!!