Varying the speed of a Marine A/C Single-Speed Blower?

[JoLin]

Last year I installed a complete marine A/C unit in my boat, all by myself :joyous:.

I bought it from Flagship Marine in FL specifically because their units are 'old school'. There are no circuit boards or proprietary electrical components. Relays, transfomer, start capacitor, etc are all off the shelf parts that are easy to find and cheap to replace. The downside is that the blower motor they use is a single phase/single speed unit. Specifically this one...

http://www.emotorpro.com/DaytonPSCBlower-1TDR3.aspx

While blower noise isn't a huge problem, there are times I'd like to step it down to a lower speed. I've heard of controllers that can be wired in place to do this, but I don't know specifically what I'd need or exactly where to wire it in. In my case, input line (110) voltage is routed to the blower relay, then to the blower.

Whatever I use has to be off the shelf- I'm not confident about assembling my own controller. I want to mount it on the cabin sidewall near the t-stat.

Anyone know of a 2-speed, 3-speed or variable speed controller that would fit the bill?

 

[dannys2004glastron175mx]

What about this http://www.ebay.ca/itm/SPEED-CONTRO...632504?hash=item1c2c7029b8:g:Nl8AAMXQlrxRZwuX

 

[JoLin]

What about this http://www.ebay.ca/itm/SPEED-CONTROL...8AAMXQlrxRZwuX

Beats me. I dunno, will it work? I don't want to do anything that might kill the blower. I've looked at these, too, but I don't know if any is appropriate

http://www.emotorpro.com/speed-controls.aspx

I know we have some experts on this forum, so hoping someone can lead me to the right answer.

 

[gm280]

WOW JoLin, you are asking for a plug and play setup and that may not be that easy. To change speed in an AC motor, you have to change the amount of the AC wave that the motor sees. And that involves TRIACs and such electronic components. And since you don't want to deal with such things, you may be looking for a while. Have you thought about contacting the actual manufacturer of your AC unit and ask them about that? They may have an add on or can tell you who supports such a setup. I could easily build one for my own use, but that is just me and how I do things.

There are lots of AC variable circuits out there. But since you want a remote panel setup and have zero idea how your present system is wired, it would be a iffy situation to recommend any system. :sorry: :noidea:

 

[sam am I]

Yours is a PSC (Permanent Split Capacitor) motor, this (or similar) will work........


https://jet.com/product/detail/b660a...nzIBoC2BTw_wcB


Careful no to buy with other less expensive types of Thyristor (SCR/Triac) as some are made/designed ONLY for AC brush type motors (drill motor, etc), those won't work necessarily well for your app/motor.

 

[alldodge]

Agree changing the speed of a single speed more will take some doing. Would be easier to find the same frame size motor that is multi speed or a slower one.

Now if this is done then you will probably start another issue. The AC was designed for a given amount of air to move past the coil. Reduce this by a restricted (dirty) air filter, or by slowing the motor down and now the coil can freeze up.

 

[JoLin]

Now if this is done then you will probably start another issue. The AC was designed for a given amount of air to move past the coil. Reduce this by a restricted (dirty) air filter, or by slowing the motor down and now the coil can freeze up.

The Marine Air (I think it was Marine Air) unit in my 27' Four Winns had a low-med-high controller switch for the fan, in addition to the t-stat. Having planned and installed my own unit from scratch, I'm aware of the possibility of the coil freezing and would be looking out for it. Air and water flow were big considerations when I laid mine out. It's as good as the best installs out there.

Sam am I, I saw that Dart controller when I was searching and wondered if that might fit the bill. Are you sure? How about the controllers I linked to in Post #3. Would any of them work? I assume I'd wire the controller between the fan relay output and the fan motor input. Given the price I might put this idea on the back burner for a little while.

GM280, not being confident enough to build my own controller from scratch isn't quite the same as having zero understanding of how my unit is wired. Not only did I install it myself, I built the new 30-amp circuit to run it, complete with breaker panel and galvanic isolation. I'm not an electrician, but I can usually find my way around an electrical circuit.

 

[sam am I]

Sam am I, I saw that Dart controller when I was searching and wondered if that might fit the bill. Are you sure?

100%, I'd stake both Dodge and GM rep's on it!! I have none to offer, lost mine back somewhere in the 80's I think.

How about the controllers I linked to in Post #3. Would any of them work?

No, all claim to be "DC"

I assume I'd wire the controller between the fan relay output and the fan motor input.

Me too

Given the price I might put this idea on the back burner for a little while.

I'm sry

 

[gm280]

100%, I'd stake both Dodge and GM rep's on it!! I have none to offer, lost mine back somewhere in the 80's I think.




No, all claim to be "DC"




Me too



I'm sry

JoLin, first of all I apologies to you because I have no idea what anybody knows on these forums and since you asked about some thing simple, and therefore I assumed, wrongly I guess now, that you had no electronic background to build one.

My best suggestion now is to go to any Air Conditioner company, around where you live, and ask about a two or three speed fan. Lots of system these days have multiple speed fans and they achieve that by multiple windings, not circuitry. So there is nothing special other then a heavy duty selection switch. In fact my old AC fan that I kept when we had a new system installed, is a three speed fan. And I am building a special fan setup for the shop with a three speed selector switch for it. JMHO!

 

[JoLin]

Okay, GM280- I didn't think building my own variable speed controller was a simple task. I obviously don't have your background. I don't want to tear the system apart to replace the fan motor, so thinking of a different kind of change if possible.

sam am I - Don't know how I missed that (those controllers all being DC). Just careless. I bookmarked that Dart controller for future reference.

Thanks, all!

 

[sam am I]

sam am I - Don't know how I missed that (those controllers all being DC). Just careless

np, the forest often escapes me and I live in the damn trees!