Fridge DC switch question - Page 2

ThePair · 06-16-2009, 08:47 PM

Quote:

Originally Posted by ferdoh

How about using a double pole switch. They are like 2 switches wiyh one lever. Run the fridge thru one and the fan thru the other. That way nothing can back feed and when the outside switch is off, you can still control the fan from inside!

Well, that would be because I didn't know these kinds of beasts exist!

So, it looks like a standard light switch, but has two independent lines in & out, and switches both at the same time? That would be exactly what I would want.

Off to go looking!

**ShrimpBurrito** · 06-16-2009, 10:11 PM

That's a good idea if you can find one that fits in your box. What kind of box did you get?

Ferdoh is referring to a double pole single throw switch, commonly referred to as DPST. Google will give you lots of info if you search DPST and switch. If you actually want two switches, to be controlled independently, but built together as one switch (and thus possibly fitting in the same space as your existing switch), you want a double pole double throw (DPDT).

Dave

ThePair · 06-16-2009, 10:41 PM

My box is a single gang, simple light-switch type external plastic all weather box. So, a DPST seems like it would be best, assuming I find one in a standard light-switch type format...which I think I can. Will stop by Lowes/HD in the next few days and see what they have available... There's an Ace HW not too far, too, if I need to visit there.

**ShrimpBurrito** · 06-16-2009, 11:20 PM

Let us know if you find one. I've never seen a DPST household light switch, but I've never looked for one, either.

Dave

Keith Wire · 06-17-2009, 05:54 AM

Sure they are available, we sell them at the hardware...

Here is a link...

http://doitbest.com/Electrical+dimme...sku-515730.dib

HTH, Keith

ThePair · 06-22-2009, 08:54 PM

Found one at Lowe's locally. Once I get it installed, I'll let you know how it works.

06-23-2009, 07:29 AM

If you have not made the change yet, why not look at the option of two switches one for fan and one for fridge. This way you can run the fridge closed at home on shore power and the fan on 12V to prepare for a trip. If I understand your system, the fan and fridge is connected after the switch so that any time either is running the fridge will be on 12V unless you have the diode installed. This may not be preferred. When I set up and pack my TM for a trip, I leave disconnected from shore power, turn Fridge to AC, and close. Then the night before we leave, I plug into shore power, Starts fridge, and flip external fan switch to run 12V fan. If I am not mistaken, the fridge works better on shore power if available.

ThePair · 06-23-2009, 09:24 AM

Quote:

Originally Posted by rumbleweed

If you have not made the change yet, why not look at the option of two switches one for fan and one for fridge. This way you can run the fridge closed at home on shore power and the fan on 12V to prepare for a trip. If I understand your system, the fan and fridge is connected after the switch so that any time either is running the fridge will be on 12V unless you have the diode installed. This may not be preferred. When I set up and pack my TM for a trip, I leave disconnected from shore power, turn Fridge to AC, and close. Then the night before we leave, I plug into shore power, Starts fridge, and flip external fan switch to run 12V fan. If I am not mistaken, the fridge works better on shore power if available.

With the double pole switch, I'll have the best of all worlds.

Outside switch on = fan on (regardless of inside switch) and fridge gets 12V power. Now, if the fridge is set to 12V, it'll turn on. If it's set to AC, it'll only go on if plugged into shore power (and it'll do that regardless of the switch status). So, to run your setup, I'd just do what you do: fridge to AC, unplug from shore power, and close up TM. Prior to leaving, Plug in, and flip switch. Fan will go on, fridge will cool off on AC, just like you're doing.

Outside switch off = fridge off if set to 12V (for parking when towing). Fan behavior will depend on the inside switch: If inside switch is ON, fan will remain on regardless of outside switch setting. Inside switch off means fan obeys outside switch.

Inside switch can turn on the fan regardless of outside switch setting, just like without any modifications.

It seems like it should be the best of all worlds. I just need to run one more wire out to the box, and put in the new switch--hopefully I'll get time today, then I'll try to remember to post pictures if anyone cares to see it.

06-23-2009, 04:22 PM

Yup. basically two switches, but in one housing.

Bob

TomNVenice · 06-24-2009, 12:31 PM

My original fridge fan blades were damaged by debris. I ordered one with a thermo switch for about $40. The fan runs only when conditions warrant it. The unit cools refrigerator coils in compartment behind the refrigerator. Used specifically for side vented refrigerator compartments.. Thermo-switch turns on when temperature goes over 100° and turns off when temperature is lowered to 80°.

It was a fairly easy install. It eliminates the need for a dipole switch.