Pattaya / Looking to buy a simple step-down-transformer for fan.

[moonseeker]

I am looking for a simple step-down transformer for a small exhaust/extraction fan. Thank you. MS>

[oncearugge]

Why would an exhaust/extraction fan need a step down transformer ?

Where was the fan sourced from ?

[lopburi3]

And if it is 120v is it not also 60Hz? Transformer will not change Hz.

[oncearugge]

And if it is 120v is it not also 60Hz? Transformer will not change Hz.

If 120v it was surely not bought locally !

[Langsuan Man]

lopbui3 is trying to tell you that motors are controlled by Hz and not just voltage. Using a transformer will slow the motor down and it will eventually burn up

Using a 60Hz motor in 50Hz duty.
w) It will turn 20% slower.
x) Cooling will drop dramatically.
y) The load's horsepower requirements will drop, possibly dramatically.
z) V/f will increase possibly causing a large increase in current draw.

source: http://www.eng-tips.com/faqs.cfm?fid=1224

Save yourself some money and purchase the correct exhaust fan, they can be purchased for much less than an inefficient transformer

[NanLaew]

Ahhh... the TV 'lectricians union have spoken. If the transformer was for a fridge, air conditioner, large fan motor or other large inductive load then yes, using a transformer is an expensive solution that will eventually end in failure but a small extractor fan? It will last for ages.

The OP wants a transformer so he can try Santi hardware opposite Foodland on Klang or Amorn in the basement at Tukcom.

[lopburi3]

At the risk of both not operating properly and additional electrical/fire hazard. In a lifetime overseas have seen far too many transformer failures to be comfortable using for no valid reason - and at first post (only post) this does not sound like one I would want to use.

[chickenslegs]

http://www.thailandguru.com/electricity-220volts-thailand.html

This is a useful source of information. Scroll down a few paragraphs to find comments on using 110v appliances in Thailand.

[Wonka]

You can use a triac regulator. About 200 Baht for a 1600 VA.

Or a variac (aka vario transformer) . About 1500 Baht for a 250 VA.

Or a capacitor in serial connection with the motor. Very cheap, but you may need to experiment a little. (And be skilled enough to mount it safely )

If you come to Bangkok, you can find these things in the Ban Mor area. Amorn group doesn't have any of this.

You can safely disregard the comments about frequency, just be sure you have enough momentum (torque) to start the motors, also when they are aging.

Be aware that some transformers you can buy here are badly designed. Too thin copper wire and big losses. The variacs you can find are ok quality.

[moonseeker]

Thank you all, especially Wonka.

I need to slow down a extractor fan / Panasonic, the ones used in bathroom ceilings to a lower speed, for a special application. I have an identical installation with a step-down transformer a friend brought me from Europe, works great and without any humming noise. Then I got one with an electronic regulator as sold on LAZADA, works great, but quite noisy.

So, to keep it simple. I need a solution to control the speed of such a fan, preferably over the full range. Was hoping it was available here, too. Again, Thanks a lot. MS>

[lopburi3]

You want a small variac transformer rather than a step-down type. They should be available. You could probably use a normal 3 speed fan control from a fan repair shop for your need.