Dimmer Switches

[scotchy]

Has anybody tried using a dimmer switch to limit the flow of their powerheads/pumps before? Just kinda came to mind and thought I'd ask.


Scott

[Gizmo]

I have the X10 Dimmers hooked up to my MaxiJet powerheads, it takes them to 50% flow at night and brings it back up during the photocycle. I would assume that regular dimmers would have the same effect. Note of caution though, dimmers get hot when they are dimming something because the energy not used is channeled through the dimmer to the neutral line. Make SURE it is overrated for your pumps, ie if the pump runs at 100W, use a 200W (thats just me).

[Rikko]

I don't think that works (safely?).. I did a bunch of research on that a while back and it sounded like powerheads are frequency-dependent and not voltage-dependent. To actually SLOW DOWN a powerhead requires a frequency dimmer - something that exists but appears to be far less common and more expensive. Choking back the voltage seems to act... differently.. though clearly Gizmo has it doing something I wouldn't have thought possible.

[BMW Rider]

Standard dimmer switches are not meant for use with motors. There are dimmer switches for fan motors that might work. They work differently from light dimmers, and are more expensive. The ones I have in my house have three speed options, not like the infinitly variable style of light dimmers. I'm not sure if they would do the job for a PH though.

[danny zubot]

Do you mean like a dimmer switch that you might find for a ceiling fan with lights on it? Or is that not safe either?

[BMW Rider]

The switch I'm thinking of is a wall mounted switch used to control the fan speed, not the lights on the fan. Similar to using the pull chain on the fan itself, except more convienient (the fan in my living room is 18' up, so the chains would have to be rediculously long, thus the wall switch). They should be available in the electrical section of most home building centers, or possibly with the ceiling fans in the lighting section. They are specifically designed to work with electric motors, and will indicate that on the switch or package.

Now for the catch, I don't know for sure that it will work for a PH, but it would be the best candidate for the job I think.

[Gizmo]

You can get "Industrial dimmers" or "electronic dimmers" if you are worried about frequency. All a power head is, is a motor. and a very low power consumption motor at that. I would never recommend trying to dim your 3000GPH Spa motor, just a bad idea. But as far as power heads go, I cannot see a problem using a standard home dimmer rated at say, twice the wattage of a powerhead. P.S. I've worked as an electrician for 4 years, we used standard home dimmers to control the speed of fan motors all the time.

[BCOrchidGuy]

The ones Ed is talking about are great, they actually turn off then turn on again at a very high rate of speed. They don't generate the heat of conventional voltage regulator dimmers. They are more expensive but they are much more reliable and safer for this application.

Doug