Dimmer Switch for 1HP 220v pool blower motor?

[jb garage]

Any body have a suggestion?

1st world problem, but my spa blower is too powerful. Its only 1HP which is the smallest one the manufacturer makes. But the bubbles splash over the side of the spa and its hard to talk in there, kind of like the news guy covering the incoming hurricane.

I figured my options are;
-find a dimmer switch that could handle this load. Its not that many amps since it is 220v like maybe 4 I can look it up. Its in a shed, so protected from the elements
-drill holes in the 2" pvc pipe below the motor to let air escape before hottub (got this idea from a pool forum)
-add an additional valve to the air return to the hot tub with same purpose as above to bleed of air, would be more adjustable than drilling holes
-try to locate a different manufacturer blower of less than 1 hp

Thanks in advance for any suggestions -

 

[fitter30]

Dimmer will not work to vary the speed of the motor. If the motor is a permanent split capacitor motor a variable speed drive would work but they cost $100+. Drilling a hole in the pipe and using a pvc repair coupling cut in half then it could be side over the hole to vary the air ir flow and clamped to hold it in place.

 

[Innovate1]

Any body have a suggestion?

1st world problem, but my spa blower is too powerful. Its only 1HP which is the smallest one the manufacturer makes. But the bubbles splash over the side of the spa and its hard to talk in there, kind of like the news guy covering the incoming hurricane.

I figured my options are;
-find a dimmer switch that could handle this load. Its not that many amps since it is 220v like maybe 4 I can look it up. Its in a shed, so protected from the elements
-drill holes in the 2" pvc pipe below the motor to let air escape before hottub (got this idea from a pool forum)
-add an additional valve to the air return to the hot tub with same purpose as above to bleed of air, would be more adjustable than drilling holes
-try to locate a different manufacturer blower of less than 1 hp

Thanks in advance for any suggestions -

Rather than adding a point for air to escape you could try adding some blockage to the air line. Contrary to what you may think blocking the outlet of most common blowers or pumps will lower the load on the motor, not raise it. There is a limit since with very low flow there may not be enough cooling.

 

[Zeke]

It could be the noise of the blower itself and lowering the RPM might seem like a solution. To that, I actually don't have anything to add since the motor likely can't be controlled per fitter30's post.

 

[dave*99]

Since the blower is in a shed you probably have good access to the plumbing. Put a T in the air line and a valve on the T. Bleed off excess air through the T.

 

[Dingleburry]

easiest IMO would be to partially block the inlet

Like others have said, dimmer wont work.
AC motor speed is dependant on line frequency/number of poles.
DC motor speed dependant on voltage.
AFAIK you can change rpm with voltage in AC motors, but only rpm, what your doing is increasing slip, not changing actual speed, and these motors are purpose built. And i believe under no load on a bench test, they will spin at same rpm. Its only under load you see the speed changes.

My guess if you put a dimmer on there would be: youll reduce voltage, slip will increase, causing current to go through the roof, motor will overheat and either burn out or trip breakers/fuses/overloads.

Just my thoughts. Correct me if im wrong. Not a motor guy.

 

[gungatim]

pool or spa? most spa's, at least every one I've ever seen has an adjustment for the blower, meaning full on bubbles to bleeding the air gradually to completely off. does your setup not have an adjustment?

if it does, is it possible the adjustment is either not working, or it is plugged/blocked where it bleeds off? for example, in the house the spa tub will occasionally get the blown cellulose insulation the builder blew in there up into where the switch bleeds the air off due to who knows what and I've had to take a brush and clean it out a few times...just something to check. my outside spa has a similar adjustment but I've never not been able to turn it down/off.

newer models maybe have an electronic control, if yours does I know nothing about them...

 

[knobby]

Restrict the output on the blower restricting the input will likely overheat the blower while restricting the output will not.