Calling all swamp cooler experts

OK kids, a new one on me, I have a swamp cooler down in the shop, last week it started to act up, it would run OK on high mode for about 5 min, then go into about 3/4 speed, (somewhere between high and low speed) I looked at the AC current and voltage, when it's running right it's 5.1 amps on low (motor and pump) and right on 10.1 amps on high, AC voltage is around 117 VAC, when it acts up on high it goes to 8.2 amps, AC voltage drops about 4 volts.

I replaced the motor, still the same problem, I replaced the wiring to the motor, (12 gauge solid) same problem, I replaced the switch, same problem, I replaced the pillow bearings on both sides and used good oil, same problem.

I checked the new motor, when this happens the motor is quite warm to hot, now.......WHAT the heck is going on?????????? This unit has run fine for about 8 years, now this pops up......It's about 100 degrees F in the shade so I need this running.

Any one?

If swamp cooler has a Riostat switch ? it maybe on it's way out, Not supplying enough voltage for fan/motor to run right
Is my Guess ? Possible combo Bad switch&motor

It's two position switch, low and high,(cool and fan only) switch contact only, and it's a new switch.

I did some web searching on your problem, it seems the "belt" needs adjusting to match the AMP draw on motor
Motor getting warm to hot, they say, is it's over amping ??

Well I checked the spec's on this cooler, on high the AC amp load should be 10.5 amps, this with the pump running, it is right on at 10.1 amps, when the cooler is set to high fan only it backs down to 9.5 amps.

When this problem happens it's on high cool and the AC load drops to 8.2 amps, the motor is quite hot at this time.

I have changed everything but the AC cord to the motor inside the unit.

Before this started the unit has run fine for 8 years, on the old motor, belt and AC supply.(in my first post I forgot to add a new belt was added)

So other then the sheet metal, motor power cord and squirrel cage fan everything is new.....I'm stumped.

I don't know what to tell you, other than could the wires to the motor be crossed
High on low side, low on high side ? Just offering up some suggestions from what i have gleaned from the web
Back in the day my Swamp Cooler consisted of a Fan blowing air over a Big block of ice placed in front of it
Now I have central air

I would try disconnecting one wire on motor (setup for single speed) run it like that see if motor over heats
it maybe energizing both sides at same time. Also does the NEW Motor have a larger shaft than old one ? (more speed more amps)
If you know the old motor still works, you can put it back in see what happens, from all the info I got from the web, the belt needs to have aprox. 1" inch of play, to tight or to loose motor can heat up.

Bad ground or neutral?

It's a royal pain in the backside to get to the motor to disconnect any wire there, let alone remove it and put the old one back..

New motor is specked the same as the old one, 1/2 inch shaft and same rotation speed as the old one, 3/4 horse power.

That is a Head Scratch-er "Alright" I have run out of possible solutions for it,
May have to get a H-Vac or Electrician to have a Look ? Hope you get it sorted out "SOON"

i dont know what a swamp cooler is but i do work on some ac are you getting good air flow?
a plugged filter or coil would be like running down the street with your hand over your face that would cause issues

Is there a capacitor on the motor???

Quote:

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Originally Posted by android fun

i dont know what a swamp cooler is but i do work on some ac are you getting good air flow?
a plugged filter or coil would be like running down the street with your hand over your face that would cause issues

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A swamp cooler uses water to wet down straw mat's buy using a small pump, a cage fan it turned by a motor to draw air through these wet mat's, the air drops about 20 degree's F in temperature, this cooler air is used to cool the living space or work area.

Swamp coolers are mostly used in hot dry areas, they are much cheaper to run the a normal AC unit.

This problem happens with or without the straw mats in place.

Quote:

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Originally Posted by wattso99

Is there a capacitor on the motor???

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Not that can be seen on the outside of the motors casing, this problem started with the old motor, new motor has the same problem.

This problem has me stumped, all electrical wiring and connections have been checked or replaced, new switch, new motor, new bearings, the wet mats have been thoroughly cleaned, new belt on the motor to the cage fan, so basically this is a new unit.

I can't figure out what could be causing the motor's to overheat, other then the local gravity has gotten stronger in that spot, and causing a higher then normal load on the motor trying to spin the cage fan.

Anything blocking the air in any way...??

Is there a squirrel cage or similar which may have lost a fin or two ? I would expect vibrations in that case but who knows...

Quote:

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Originally Posted by wattso99

Anything blocking the air in any way...??

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Nope, the air goes down, takes a right turn and directly dumps out into the shop, also opening a door or the roll up door does nothing.

Have you tried plugging the cooler into a different 110 vac outlet................

Your "Not" using a extension cord with it ? and try Loosening the "Belt" a Hair, apparently Pulley has to match motor
amp/voltage draw from all the info I have found on it. Don't know what else to suggest to solve your problem.

so normal operation is 10 amps

but your getting 8 amps and the motor is hot.
i am think the belt tension but that and are flow should increase amps not bring it down.
a slipping belt would cause less amp draw but not make the motor hot

this is just 120v so not like 3 phase and you lost a leg
i think maybe try a different plug in might be a power issue.

new thought



your new motor is it 220/120?
could it came wired for 220 and you hooked it up to the 110?
i have done that before didn't change the jumpers inside the motor head.

did you figure out the issue?

Quote:

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Originally Posted by steveOtoo

Have you tried plugging the cooler into a different 110 vac outlet................

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Yup...No change.

Quote:

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Originally Posted by auggie

Your "Not" using a extension cord with it ? and try Loosening the "Belt" a Hair, apparently Pulley has to match motor
amp/voltage draw from all the info I have found on it. Don't know what else to suggest to solve your problem.

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Nope, no extension cord.

Same pulley as the old one, new belt, and it's tightened to spec for the unit.

Quote:

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Originally Posted by android fun

new thought



your new motor is it 220/120?
could it came wired for 220 and you hooked it up to the 110?
i have done that before didn't change the jumpers inside the motor head.

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New motor is 110-125 VAC, same as the old one, and no way to connect it to 220, it's 120 only.

Quote:

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Originally Posted by android fun

did you figure out the issue?

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Nope, and some professional electrician friends stopped by yesterday and looked at everything, all the way out to the main service panel, tightened all connections and even traded out the breaker for that circuit, it still does the same thing.

What they suggested is that the air is somehow restricted through the mats, causing a higher load then usual, we are going to town on Tuesday, will get new mats, and a new pulley for the motor, the new pulley is just to see what happens.

well to test can you pull the mat out and run it?