SPDT VS DPDT?

[wildman]

Ok trying to rewire the boat and need some help.<br /><br />I have a switch that when you flip up it turns on one set of lights, when you flip down it turns on a different set of lights.<br /><br />What kind of switch do I need to replace this?<br /><br />what is the difference between the DPDT and SPDT?<br />I know what they mean, but I dont understand the wiring.<br /><br />Thanks

 

[Paul Moir]

Re: SPDT VS DPDT?

S ingle<br />P ole<br />S ingle <br />T hrow<br /><br />D ual <br />P ole <br />D ual <br />T hrow<br /><br />Throws are the number of conducting, or 'on' positions the switch can be in. Poles are the number of switch circuits. A Dual Pole switch is like pressing two Single Pole switches at the same time.<br /><br />If the switch has a middle position, say "all off", you need a SP3T.<br />If the switch has only two positions, say on (one set of lights) and on (other set of lights) you need a SPDT switch.<br />If the switch has two positions, but only one on position and the other off, you need a SPST switch.<br /><br />Of course, you don't have to use the other poles, or the other throws, so you can use a DPDT switch in a SPST application, or a DPDT switch in a DPST application.<br /><br />So by your description, you need a SPDT switch or better (ie, a DPDT or a 3PDT or a... Just as long as it ends in DT)<br /><br />Clear as mud?<br /><br />SPDT:<br />

<br /><br />DPDT:<br />

<br /><br />SPST:<br />

 

[wildman]

Re: SPDT VS DPDT?

Yikes!<br /><br />Thanks for the great Info That makes it a lot easier

 

[18rabbit]

Re: SPDT VS DPDT?

Good stuff, Paul!<br /><br />Wildman – If you are using a single pole switch you should only be switching the voltage (+) for those lights…DO NOT switch only the ground (-). Personally, I would be using a double pole switch that makes/breaks both the power (+) and the ground (-) at the same time, electrically isolating the lights when “off”.<br /><br />EDIT: One more quick note about switches…unless you are matching the appearance of an existing panel, switches are less expensive thru online sources. There is no such thing as “marine grade” or “boat” switch. They are typically just switches that are either rate NEMA 4 (water proof) or 4X (waterproof and corrosion resistant). Try looking here: www.mscDirect.com