ECN Forum Forums Photo Discussion Forums Photos for General Discussion Can you identify this plug?

Sean wins the rubber chicken! It's from a 'swamp cooler.' http://www.wonderquest.com/swamp-coolers.htm

Used in arid areas, in many situations these low-power units replace energy-hog air conditioners.

They typically have three settings: fan only, low cool, high cool. The "low" and "high" are accomplished by changing the fan motor speed.

The fan motors come with plugs that match the female end that I posted. The motors are 120; one pin feeds the 'low speed' winding, while another pin feeds the 'high speed' winding. The pump plugs in to another receptacle. Both of these receptacles are inside the unit, mounted on the side of the control section.

From a code standpoint, you still need another disconnect on the outside of the unit. Simply unplugging the fan and pump will not turn off power to the control section. It would be most unfortunate, were the fan to operate while you were inside, changing the pump.

Industry standard? Yup! maybe not "NEMA," but many different manufacturers of the units, as well as the replacement parts, use these plugs.

Though, I really ought to take one of these plugs to the supply house, just to drive them nuts

Reno, you learn something new every day, I'd never heard of a 'swamp cooler' before.

Is there a risk of legionella with a unit like this?

Alan

ive had to rebuild several swamp coolers especially replacing these plugs we have hundreds of them here in palmdale were in the desert

We had one at a resort I worked at. It worked quite well, although we were in a pretty dry climate. I suspect it wouldn't work as well in more humid climates. The only servicing it required was the occasional cleaning, to remove the sediment (well water) from the rotating filter and water-recycling tray.

There are 5 settings, High and Low cool, pump only and High and Low vent. Cool setting runs pump and blower, Vent setting runs blower only.

Alan, while I am no germ guru, I would say "no." The unit continually receives new tap water ... chlorine and all! The main purpose of the unit is to make that tap water evaporate, and be mixed with the fresh air being supplied to the room.

Inside the unit is a shallow pan, that holds the 'supply' water. This level is controlled by a float and valve, not much different from what you find in a toilet tank.
The pump takes the water, and delivers it to the top of a 'pad.' I've called this pad a sponge, but that's not really correct; the bad does not absorb water at all. Rather, the pad material is more like a scotch-brite pad, or a 'waterproof' straw. As the water cascades down this pad, air is passed over it. This is where the water enters the air.

The holding pan can become an algae farm, especially if the unit is not used very much. Other than a bad smell when the unit does start up, I'm not aware of any particular health risk. In any event, there are productas available to deal with this problem, if it occurs.

The key difference between a swamp cooler, and a "chiller", is that the water is NOT recycled. The water makes a one-way trip through the cooler, and generally isn't in it very long.

I was going to guess a compressor plug (plugs a wiring harness to a sealed compressor unit).

And yes, I know what a "swamp cooler" is. Unfortunately I like in a high humidity area, and cannot effectively use one.

I have hooked up and serviced many swamp coolers while living in New Mexico. They are great as long as the humidity in the air is very low. If you have a high humidity day (not often in NM) they don't work at all. In arid climates they are a economical alternative to refridgerated air. On a standard ranch home, the cooler would typicaly mount on the roof above the center hallway, and vent straight down to a register with directional louvers. We would mount a steel box and run EMT up and through the roof to a WP box mounted on the side of the cooler. You would put your disconnect switch there, and then wire the unit. Every year, the pads need to be changed, the motor serviced, the pump and unit cleaned and every few years the bottom of the cooler coated with anti-corrosion compound. I have even seen big commercial units with 240V motors and more sophisticated controls, but anymore, at least in NM swamp coolers are being phased out. Refridgerated air systems are cheaper and more energy effecient than they were, and work much better. But in NM, in the 50's, 60's and 70's swamp coolers were the norm and many are still in use today.

Hmm, electrical connectors & swamps. I just can't help picturing a certain group of frogs and a loose neon sign......

Seriously though, I had no idea what a swamp cooler was either. I don't think there'll ever be much call for them here (well not unless global warming really takes a hold).

Ours used a belt of the scotch-brite material, that ran through a pan of water. Algae really wasn't a concern in that climate, although being a dusty area it would often get clogged with fine silty mud and require cleaning every other month.

Even so, it was a very effective and efficient cooling solution for the climate.