SPDT Relay contacts strong enough?

[shizzzon 461]

I'm planning on using some exotic wiring on being able to switch from 2ohm to 0.5ohm for competition via a switch so i do not have to rewire for an hour at every show.

 

I see some copper made 80A relays.

 

What i want to know is this, here is my scenario-

 

Maximum burping current draw can be up to 85A AC.

So i opted to use 2 80A relays per speaker in parallel for 160A of heat dissipation.

 

Since Relays only use 10AWG quick disconnects, will quick disconnects be sufficient enough for this wiring? 

 

I plan on running modded inserts for 4awg wiring off each terminal of sub to a junction block.  Then from there, 10awg to each relay pin, output to another junction box of 8awg wiring which goes to amp.

 

I would love to find some 5 pin SPDT high current relays that did not require quick disconnects so i could just use same wire awg throughout.

 

The main thing i'm concerned about is will these relays greatly restrict potential power coming out of the amp?

I've never measured output loss on these kind of high ampacity relays so do not know what to expect.

[95Honda 486]

If they are truly rated for that current, and you are running them in parallel, then you should be fine.  Insertion loss will be minimal.  As long as you don't switch them under a load the contacts will last forever for your application...

 

The terminals will probably be OK, just make sure you make a real tight connection so no heat builds up where this is little contact area....

[altoncustomtech 773]

The only thing I question is the quick disconnects.  

 

Working in the industrial world I work with lots of relays, motor contactors,  motor control centers, etc. and I don't think you'd have an issue if the rating wasn't being exceeded much or for very long.  If you want to keep your large gauge  wiring and have something that's guaranteed to handle the current with no problem look into a small contactor style relay.  It will have set screw terminals and they can be found with 12v coils in them.  The only problem is they're not cheap, but then again, if you wanna play ya gotta pay right?

 

 

Lemme look around at what's available in the industrial world and I'll post back up here with some options.

[shizzzon 461]

95honda-  that's what i'm thinking.. if it's rated for it.. then it should be fine.

 

I would never risk switching them while a load was present.  I'd probably be switching these literally like less than 60 times a year.

 

I guess what i could do is after wiring everything up and making sure it's wired right, i would just put the connectors back on the terminals and just solder the terminals on the relay.

 

 

I'm still open for what you can find Alton.

 

To do this, for my method of distributing the heat with 2 relays, it takes 4 relays per speaker to do it.

2 pairs in series.

[Quentin Jarrell 671]

http://www.drillspot.com/products/43136/white_rodgers_124-305111_dc_power_solenoid

 

I'm sure if you search White Rodgers will have something else that will work better.

 

 

Edited June 20, 2013 by Quentin Jarrell

[shizzzon 461]

I know about those but for this project, that's too much money for what use i'm using it for.

 

I will need a minimum of 10 of those, 2 per speaker, to wire and i don't see myself spending over $500 in relays for one use.

[///M5 2,833]

I use relays at home to fire a 15A 110V source.  Allows me to turn on a pro audio amp that has no on input.  If they can handle that load I don't see why you should even be concerned about yours.  I fire it with 12v so they should be fine in a car as well.  IIRC they were about $15 each, but I could be wrong there.

[shizzzon 461]

Im just afraid these quick disconnects will build up resistance overtime like how a 

Loose connection would do based on how they connect.  Im still considering soldering

Them on once i verify the wiring is right

[95Honda 486]

Soldering would be good.  Just be careful not to overheat if the base material is plastic.

 

You know, Parts Express has buyout Bosch type relays for about a $1 or 2 quite often, keep an eye out foe those.  Just parallel as many as needed.  You are also cutting down on your terminal resistance that way...

[nadcicle 77]

Shizzon, If you find some cheaper ones just make sure to look in to the tech specs on them as I bought about 4 of them once and once I received them they were 10amp open side 50 amp closed side. Apparently these go for much cheaper than a 50/50 and etc. First thing i thought of when you were doing this is to just find an industrial programmable plc that is capable of handling the higher amperage. It'd be pretty neat to have a switchable push button throw to handle all of your ohm swaps i think.