Wiring up a relay

[Ruahrc]

I am setting up a watercooler and would like it to be relay-driven. I looked at a site with an explanation but had some questions about it as the page wasn't too clear on what to do.

First of all my water pump is 3.4W, 110VAC powered. The relay I intend to use is Radio Shack Part# 275-218C, rated 5A at 240VAC, and a 12v trip coil. This relay will be able to handle the power required for my waterpump, right?

Now I had a question about the wiring. On the bottom of the relay there was 4 sets of 2 pins or leads. One was the 12V coil, another connected the relay to the plug that goes in the wall, and another connected the pump to the relay. I was wondering on how to wire the thing up. Do I take a +12VDC wire from a molex and have the relay "pass-through" it? Or do I need to hook up a +12 and -12V wire, one to each lead? Also about the wiring of the pump. From what I see it as, the relay basically sits in series between the pump and the wall outlet, and trips up only when 12V activates the coil, right? So why are there 3 power connect leads on the relay? In the end it seemed as if one set of leads was not used. This confuses me.

Any light on this subject would be greatly appreciated. (and soon to be rewarded with pics of my will-be-done watercooling system hehe)

Ruahrc

P.S. The website I was looking at can be found at: http://www.overclockers.com/tips242

[Xeroid]

I didnt find a Radio Shack Part# 275-218C on their web site. I did find this:
http://www.radioshack.com/product.asp?catalog%5Fn ame=CTLG&category%5Fname=CTLG%5F010%5F008%5F005%5F000&product%5Fid=275%2D218 (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F010%5F008%5F005%5F000&product%5Fid=275%2D218)

Is this the relay in question? If so, this relay requires +9.6volts d.c. and a ground to energise. Take a look at the wiring diagram:
http://www.radioshack.com/SupportGate.asp?SupportPage=%2Fsupport%5Fsupplies% 2Fd oc9%2F9525%2Ehtm (http://www.radioshack.com/SupportGate.asp?SupportPage=%2Fsupport%5Fsupplies% 2Fdoc9%2F9525%2Ehtm)

If this is your relay, then your 110v a.c. device could be connected in series with pins 4 & 5. Then when 9.6 volts d.c. is applied to pins 7 & 8 the relay will energise. This will cause pins 4 & 5 to close and thus conduct.

If this is not your relay, please post a hyperlink to it so I can take a look.

Mike



[This message has been edited by Xeroid (edited 07-04-2001).]