kill power to amp on fan failure

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Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=128278
Printed Date: June 11, 2024 at 8:48 PM

Topic: kill power to amp on fan failure

Posted By: girouardmatthew
Subject: kill power to amp on fan failure
Date Posted: August 18, 2011 at 10:26 AM

Hello,

I'm new to 12v. looking for some help wiring an amplifier enclosure. I have two amplifiers enclosed with 2 fans introducing air and 2 relieving air from the box. I want to know how to wire them so if the fans fail for some reason..or they break, they will kill power to amplifiers so they do not overheat and break.

Am I too concerned about wiring it this way..as in it is not necessary. I do have thermal protection but do not want to rely solely on that to save me. I have relays and stuff. understand them well. but am not sure how to take care of this problem.

Any help would be greatly appreciated.

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Take Pride In Your Work. Take the time to do it right. Ask millions of questions to do it the right way.

Replies:

Posted By: girouardmatthew
Date Posted: August 18, 2011 at 10:26 AM

I have a Mazes protege. 99.

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Take Pride In Your Work. Take the time to do it right. Ask millions of questions to do it the right way.

Posted By: oldspark
Date Posted: August 18, 2011 at 11:15 AM

Either:
Klixons (temp switches) on heatsinks etc (eg, normally closed types; open when over temp)
Else a vane switch (air stops, flap/vane closes and opens switch).

The latter is more preventative but needs bypassing to power on, and a filter (delay). Any air blockage triggers them.

Klixons are probably simpler and more reliable, but act once heated. But hence also trip for overloads.

Posted By: girouardmatthew
Date Posted: August 18, 2011 at 2:39 PM

is there a store I can get them or do I need to get them online? just needed it asap.

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Take Pride In Your Work. Take the time to do it right. Ask millions of questions to do it the right way.

Posted By: oldspark
Date Posted: August 18, 2011 at 9:23 PM

I'm curious why ASAP? Fans should not fail often.
And FYI, presume you have 2 fans at the intake, not one at each end?

For Klixons (a brand name that has become generic), see Jaycar, though you should find local equivalents.

But be aware, those switches mat not be high enough temperature wise for your liking.
And note the choice of NO and NC versions.

My last klixons were purchased for $1 each from a guy that imported them specifically for electronics - solar regulators, amplifiers etc, but I can;t find his website. His ranged from about 80°C to 140°C with inter-decade values (eg, maybe 96°C, 132°C, etc) and I think were usually normally on (NO) as you probably want.

Vane switches are usually DIY - a simple hinged blade or vane under spring pressure. When not blowing, they open a NC (normally closed) microswitch.

But decide what you want.
If measuring those fans, probably the vane switch.
If monitoring actual temperatures, then thermal switches.

There are also air-flow sensors as used with EFI....