Second switch for waterpump

HoneyBadger · 7 Mar 2017 at 10:48

Hi all,
Just need a sense check - what I'd like to do is add a second switch (vandal switch) to enable me to turn on the water pump

Am I right in thinking that if I tap into the ATX cable, replicating this and and not the whole system.

https://www.dazmode.com/store/uploaded/thumbnails/db_file_img_6007_800xauto.jpg

The switch, when 'on' will bridge the connection and just power the pump, when 'off' it would just work normally.

Is that right?

** Do Not Hotlink images **

whiterabbit · 7 Mar 2017 at 17:53

That's an ATX jumper. It will power anything connected to the PSU.

HoneyBadger · 7 Mar 2017 at 19:18

Ok, so how would I achieve just turning the pump in?

Holst1981 · 7 Mar 2017 at 19:42

It's difficult to do this from your pc psu.
As other than unplugging everything but the pump I can't think of any other way to do it.

I tend to use an old psu for leak testing and just power my pump from that, but it's more complicated than a switch.

If your handy you could do the following.

Add a switch into your pump power cable that has 2x3 poles. Common goes to the pump, position 1 to your pc psu. Position two to a separate 12v psu.
You don't want to plug an external 12v source into your pc psu. The switch lets you isolate the pump and power it separately.

Personally I would be worried about leaving the switch in the wrong position and not turning my pump on with the rest of the pc.

An alternative is to use a relay to disconnect your pump from your pc psu when you plug in a external 12v supply for the pump.
That should be easy enough to set up and is foolproof.
External 12v plugged in - only pump runs and rest of pc is disconnected.
External 12v unplugged - pump powered from pc psu.

new boy · 7 Mar 2017 at 20:08

Can I ask why?

Thekwango · 7 Mar 2017 at 21:36

new boy said:
Can I ask why?

guessing the only answer to this is that he wants to leak test? can't imagine any other reason for wanting to be able to power the pump separate from the rest of the pc

new boy · 7 Mar 2017 at 21:48

A 2nd hand decent-ish (FSP) PSU of ebay can be had for a fiver though :S that's the route I took.

Compared the cost of a loop, its nothing, and it will be needed again and again as you perform maintenance and/or change the loop.

Thekwango · 7 Mar 2017 at 22:25

new boy said:
A 2nd hand decent-ish (FSP) PSU of ebay can be had for a fiver though :S that's the route I took.

Compared the cost of a loop, its nothing, and it will be needed again and again as you perform maintenance and/or change the loop.

true. I have a couple of spare Compaq psu's from old machines I stripped down a couple of years back that'll serve the same purpose

HoneyBadger · 7 Mar 2017 at 23:10

Thanks all, particularly holst1981. Spare PSU's aren't an issue, I've got a SFF Strider and a Corsair RM1000i spare!

As you've guessed, I just wanted an 'easy way' of maintaining my loop going forward, I thought this would be easier than it actually is!

I remember my old z87 Impact had a button on it which essentially did what I'm trying to achieve, I'll have a ponder based on what holst1981 has put and report back in due course!