Any "Sparkies" out there?

[jimyoung]

Can any of you electrical guys insert into this schematic the components needed to have the fan come on when the pump/compressor and go off with them as well?

   


The 2-knob control panel switches are a three position knob that is "Off" - "Fan" - "A/C" and the thermostat.  I want for the "Fan" position to turn on the fan as it does now and to cycle with the compressor when on A/C.


Thanks in advance for any help.
Capt'n Jim

[MacGyver]

If I am reading this right, you would need another relay. But I am unable to route it properly...... Might just be that at the moment I have too much on my mind though, which I do....

I will print it and take it to work and see if on a break I can route it. I dabble in this stuff, so cant say I am a very trustworthy person on it though. So far my success rate is like 70%.

Mac

[jgsharpe]

Good puzzle.  You should be able to take the black wire from terminal #4 and move it to terminal #3.  That parallels the fan with the compressor, so when the compressor turns on, the fan will be energized as well.  I think the potential weak links in this plan would be the current rating of the T Stat and switch, they would need to carry both the load of starting the compressor and the fan in this scenario.  If they are not not able to carry the load, they could fail.  McGyver's suggestion for a relay could enable the same result without loading the switch and tstat, using the T Stat to energize the relay that in-turn fires up the fan.

[jimyoung]

Thanks guys,
jgsharpe,
Good simple fix.... must admit that I thought about this one but from what I see if I do this I cannot run in the "fan only" mode.

Mac,
When the fog clears ( ) I would be grateful if you took a look at it again... I think that this is the way to go but don't know enough to know where to place it or what to relay "spec".

Again, thanks to both of you!

capt'n Jim

[jgsharpe]

Hi Jim, you're right, that removes the 'fan only' choice and makes it a 'fan and AC' position.  I thought that was what you were hoping for.  If you want to keep the fan only and add the fan and AC option I think you are looking at replacing the switch with one with another position and probably a double pole type.  Is that an option?  

Update - I just sketched a way to do this with an additional switch, a double pole / double throw type.  One position is 'normal', the other is 'Fan + AC'.  the 'normal' position means the three position switch you have now works normally.  The Fan + AC is the new mode that is just that.  This is a simple wiring mod, and you could de-install it at any time to get back to where you are now. 

Jim, drop me a note and I'll send you the sketch.  my email is jeff.sharpe@turner.com

[jgsharpe]

Hi Jim,  here's the schematic with the new switch.  Hope it's what you're looking for.  Give me a shout if you have any questions.  Jeff

[jimyoung]

Jeff,

This is even better than I was looking for since I can keep the "look" original and will not have to modify the thermostat mounting or location.  Thank you so much!

BUT!! After looking again at how I originally installed the A/C unit it will have to wait until I need to pull it out before I can get access to the terminal strip.  Since I am taking my trip starting this Saturday, and I can only easily access the fan switch and thermostat I am looking at your original thoughts and am curious.... Could I disconnect the red wire that connects to terminal 4 at the fan switch and run a new jumper wire from there (#4 on the fan knob) to the #2 terminal on the thermostat?  Would this give me the same results as moving the #4 to terminal #3?

Thanks again on this, as you can surely tell, even though I have rewired my entire boat at one point or another in the 20+ years I have owned her I am not too sure of myself when it comes to modifying the schematics and like to have someone more educated than I look over my intention. 

Thanks again.

Capt'n Jim

[jgsharpe]

Pretty close.  Instead, disconnect the Red wire from the switch (#4 at the switch) and reconnect it to the thermostat (#2 at the thermo).  That would be exactly the same as moving the black wire from #4 to #3 on the term strip.  (Do not disconnect the black wire from thermo #2, though, or you will kill the compressor.)

If you do this, you may be pushing the current rating on the thermo since it's energizing the fan and the compressor at the same time.  Not enough info on the schematic to know for sure.