How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Phil Your Own Question
Phil
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 7596
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
23932409
Type Your HVAC Question Here...
Phil is online now
A new question is answered every 9 seconds

I have an evaporative cooler which uses an Evirotech VSM57

Customer Question

I have an evaporative cooler which uses an Evirotech VSM57 variable motor.
On startup the fan rotates the wrong way.The
unit Has a controller not a remote. Any suggestions ?
Submitted: 1 year ago.
Category: HVAC
Expert:  BillyHvac replied 1 year ago.

Hello.

This is indicative of a burned thermistor in the motor end bell. Generally this is only resolved by replacing end bell or motor.

Customer: replied 1 year ago.
I replaced the motor and it still has the same problem.
Nothing has changed.
Expert:  Phil replied 1 year ago.

Hello,

You have eliminated the motor as a cause, that leaves only the printed circuit card or the ECM motor driver. Look over the link below and tell me which one your system uses.

http://www.enviro-tec.com/pdf/iom/ENVIRO-TEC_G3PWM_SingleSpeed.pdf

We can go from there.

Customer: replied 1 year ago.
The motor is connected to a Tekelek 297.
It is a variable speed motor.
Expert:  Phil replied 1 year ago.

Thanks

If you do not have a variable speed wall switch or a two speed wall switch, and just the Tekelek controller by itself, then the odds are nearly 100% that the Tekelek 297 has failed.

http://www.actrol.com.au/Products/Air-Conditioners--Heating/Evaporative-Coolers/Tekelek-Evaporative-Cooler-Parts/

..........

Please remember to rate my service before you leave today. It is how I earn a living, and does not increase your charges.

If you need anything else, just let me know. You can continue asking follow-up questions at no additional cost.

Customer: replied 1 year ago.
The unit has a variable speed wall switch/controller as well.
Expert:  Phil replied 1 year ago.

Thanks,

Tell me if you have a multi meter to check the resistance changes out of the wall switch controller as you change the setting from off to high speed slowly... if the controller is good it will change from infinite ohms when set to OFF, and increasing ohms as you gradually change the speed setting.

You can buy a $30 ohm meter to do that if you like at all hardware stores.

If that checks out OK we need to replace the 297 unit.

If the variable speed controller does not provide a gradual change in resistance as you move the setting from OFF to high speed, then all you need is a new variable speed wall switch/controller.

...............

Please remember to rate my service before you leave today. It is how I earn a living, and does not increase your charges.

If you need anything else, just let me know. You can continue asking follow-up questions at no additional cost.

Customer: replied 1 year ago.
i have a multimeter. Will test it tomorrow.
How if that being faulty cause the motor to turn
the wrong way ?
Expert:  Phil replied 1 year ago.

Good question. A bad speed control will probably not cause the motor to turn the wrong way, but it is the least expensive of the parts involved, and is worth eliminating as the cause even if the probabilities are low.

Customer: replied 1 year ago.
The ohms on the controller changed
with changes to the controller dial.
It went from a high ohm reading to
zero ohms at the high speed end
of the dial.
Expert:  Phil replied 1 year ago.

Thanks,

The wall switch speed controller is most likely OK in this case, that leaves the larger 297 module as the only remaining suspect.

If you appreciate my input so far, and wish to continue with virtually no time limit, rate my work positively... we can go from there. The company only pays me if you rate positively, lacking that I can spend days with a customer at my own expense, without any compensation.