Control of an 220V AC office fan 2

[JohnStorm]

Hello, I am trying to find a method of using a thermocouple to switch on a 220V AC office fan at a preset temperature. Are there any simple inexpensive design solutions to this? Any help would be appreciated, Many thanks

 

[dpc]

You need a line voltage thermostat, or a pilot-duty thermostat with a relay. This will be much simpler than trying to interface a thermistor.

Check Honeywell or Square D. Thermostat must be hp rated for the appropriate motor size

 

[JohnStorm]

Thankyou for the information dpc!

 

[jbartos]

Suggestion: Visit

http://www.electric-flight.org.uk/data/thermostat.htm

(for electronic thermostat)

http://www.lodgingac.carrier.com/Files/LodgingAC/Local/US-en/52cp-1w.pdf?SMSESSION=NO

(wiring diagram)

http://freepoolheat.com/woodburner/

(for a furnace)
etc. for more info

 

[JohnStorm]

The dc fan thermostat circuit looks quite good, I'll probably have to look at dc fans rather than A.C. Looks like controling a.c. fans could be expensive and beyond something I could attempt.
Thanks for your help jbartos

 

[redtrumpet]

http://hbctradeline.honeywell.com/C...sp?FAM=Therm_Line_Volt&ITEMLIST=129521,129523

 

[inventer]

most any scrap or recycle yard will have old junk airconditioning or electric heaters all have on off switches that work a 110 v or 24 v electromagnet to close the circuit (i just bought one it was 2 bucks at the scrap yard) a three phase switch will work for you will only be using 2 of the lugs you will need a power supply (witch should be near the switch somewhere) and a thermostat that will cure your problem for about 5 or 10 bucks at the most good luck if you need ? my email is lostinventer@hotmail.com

 

[HalfData]

I don't know about your expenses but accuracy is a definte factor when using a line voltage thermostat. Depending on the model, you might get a vague idea what the temperature is. The bi-metalic strip is carrying the full load of the current, in your case, the 220 volt fan (depending on the size) would use less current than a 117 volt one, but whatever current is present, can throw the line voltage one off. Add to this, poor calibration, slow reaction and wide temperature swings are common so you might end up waiting or getting a larger power bill for whatever you use the fan for, cooler room for example.


If you want accuracy, get a electronic line-voltage thermostat (ELVT). In these units, a lightweight thermistor senses the temperature while semiconductors control current to the heater. ELVTs are more precise, better calibrated and have lower temperature swings (technically called hysteresis). These have greater accuracy, and the temp is reflected in the dial, which indicates temperature settings with actual numbers, and might be worth the cost for the possible extra comfort. Hope this helps.

I'm new and hopefully electrical forum will be shown after this post, since I'm in a few selected forums.