Pump relay
 

The general concensus is turning a pump on and off with a relay is bad news, and the reasoning is good. What I want to know is who has had a pump die on them due to this (I know you can't prove it for sure), especially if it was a higher quality pump such as Eheim or Danner. No doubt the life of the pump is shortened... but if it goes from 10 years to 5... well, you get my point.

I'm about to build my first watercooling setup and am going to use a relay. Also, so that I can turn the pump on without having to turn the computer on, I am also wiring in an on/off switch next to the relay so that I can bypass the relay if I want to. What I most likely will do is turn the pump on in the mornings and leave it on all day untill I go to sleep, regardless of the computer being on or off.


Well.. I was going to draw a little ASCII picture of the setup, but aparently, the spacing gets all screwed up... I can describe my plans in more detail if you want...

On a magnetic drive pump there is nothing you can harm turning the pump on/off. A magnetic drive pump is nothing more than electromagnet with north/south poles. The rotor/shaft has imbedded plates. When electricity is applied to the electromagnet the shaft begins to spin. Very simple design that is used in many applications that are turn on and off hundreds of times per day in some applications. So enjoy using a relay, I do.

Re: Pump relay
 

It's not a general consesus, it's still highly debated (case in point!)

Why don't you explain your view on the situation, then we'll try to come to a logical conclusion...:cool:

My Eheim 1048 has been switched on/off daily since new year. It is still going strong without any signs of problem...

... and as soon as the rest of my watercooling stuff arrives, I will be enjoying a relay I bought from DodgeViper :D :D

Here is an image of the relay Lord is talking about. I still have a few left.

http://forums.procooling.com/vbb/att...p?postid=25350

I don't have pics right now but I like relays I have a nifty one that is real easy to use. I post pics later today.

Yeah and I still want one of those web hehe

If people want to be more certain that their particular pumps can be regularly turned on and off, look for discussion of how well said pump works with aquarium "wave generators" as these devices require the pumps to be turned on and off hundreds of times a day. Indeed, the aquarium folk _Have_ come to some consensus on this and have seen that some pumps ar ebetter for this than others.

There is another problem with leaving the pump on all the time while shuting down your PC....

Heat

My ViaAqua 1300 required 20watts to run, most of which is heat. I left my running today for 1/2 hour and water temp reached 32C.

As for pumps in wave setups, I doubt (in my opinion) that turning in on once or twice per day will seriously affect the life span. Heat probably would.

Again, no proof, just my reasoning and opinion.

Here are the pics of the relay. The one end plugs into the power supply and the normal computer power cord plugs into the other side. On the bottom is where the pump plugs in and the wire plugs into a fan header.

http://community.webshots.com/photo/...40275517swzQDL

...that wire looks too short to reach a fan header lol

No prob it can be made longer but I have already had it hooked up so I know it's ok. Fragenstien has seen it hooked up and running also.

Personally I would use a solid-state relay over a mechanical relay. Less chance of something going wrong. No moving parts on a solid-state relay.

Not to sure that ppl need a relay at all?
My Eheim is wired straight to the mains plug on the comp psu (thru a service switch) so that when the wall skt is switched on then the pump starts before i go anywhere near the computer. I do have the service switch wired inside the case for testing/filling use but this is left in the "on" position so my pump is always switched on or off by the wall supply or in my case the multiplug thats plugged into the wall. Takes the doubt away completely, it seems to me, and the juice is flowing before the comp starts up which can't be bad.

Also, shouldn't relays be wired with arc suppression in the circuit to inhibit the back emf.

I'm not saying it's wrong to use a relay , just that it might be overkill :cool: ;)

Of course DC pumps are a different ball game:)