I found out belatedly that Thermador VTN 600 cfm blower (not VTR600)
for HT30HQ hood has no adjustable speed feature, just on and off. I'd
like to conver it into adjustable. Can you help me on this?

---

Request for Question Clarification by sublime1-ga on 24 Mar 2004 20:21 PST

thanks4info...

You could probably get an electrician to install a 'rheostat'
or 'potentiometer' for a reasonable fee. A rheostat or 
potentiometer is basically a variable resistor used to change
the voltage or current delivered to an appliance.

Does this sound like a workable option for you?

sublime1-ga

---

Clarification of Question by thanks4info-ga on 24 Mar 2004 21:19 PST

Is rheostat or potentiometer normally available at an electrical
supply store? Is it different from "variable speed control"? What
should I ask for? Does amp matter (the blower has 4.3 amp rating)?
Hope that this clarifies my question. Thanks.

---

Request for Question Clarification by sublime1-ga on 24 Mar 2004 22:52 PST

thanks4info...

Yes, a rheostat or potentiometer would be available from
an electrical supply store, or perhaps even Home Depot.

It would be the same as a variable speed control. It all
depends on the application. The lighting dimmer mentioned
by hlabadie-ga is a typical example, though you will need
a higher-rated one. The formula is Watts = Amps x Volts,
so a dimmer switch operating 4 60-watt bulbs would have
to handle 240 watts/110 volts = 2.182 amps. Yours needs
to handle 4.3 amps. At 110 volts, that's 473 watts. You
may find that the potentiometer you need is rated in watts
rather than amps, in which case you should find one that
is rated for at least 500 watts, since, at 115 volts, the 
wattage would be 494.5, and at 120 volts it would be 516.

An electrician should be able to locate the proper unit,
but if you plan to install it yourself (perhaps with 
guidance from the staff at Home Depot), the information 
above should be all you need to work with.

Let me know how else I can be of help, or if you arrive
at the conclusion that you have what you need, let me know,
and I'll post a formal answer.

sublime1-ga

---

Clarification of Question by thanks4info-ga on 25 Mar 2004 13:04 PST

Sublime1-ga

Thanks. It was quite helpful. I will get the part tonight and try out.

---

Clarification of Question by thanks4info-ga on 25 Mar 2004 13:45 PST

Speed Controls, Lutron
... FS5F WH LUTR SPEED CONTROL, 14.90 ea. ... BX Cutters Siemens
Breakers Simkar Fluorescents
Lenses Sockets Smoke Detectors BRK Speed Controls Lutron Square D ... 
www.electricsupplyonline.com/prod/ speed_controls-lutron.php - 34k -
Cached - Similar pages

Lutron FS5F is what I am going to try. Am I on the right track?

---

Request for Question Clarification by sublime1-ga on 25 Mar 2004 15:43 PST

thanks4info...

Gee, I don't know. This is not the sort of item I would
risk buying over the internet, sight unseen. The page
you referenced doesn't have a picture of the FS5F, nor
do I see a wattage or amperage rating. Personally, I 
prefer to deal with a human being to help me narrow 
down the best device with the appropriate rating for
the task. Buying an item like this over the net is
more of a hit-or-miss proposition, and returning 
the item if it's not just right would be potentially
expensive and difficult.

Especially if you're going to do this yourself, you
may be better able to determine what will look good
and install more easily by seeing the units in a
store, where you have the option of returning them
easily if the installation doesn't work out.

That's my take on it, anyway.

sublime1-ga

---

Clarification of Question by thanks4info-ga on 26 Mar 2004 15:38 PST

I got the part from an electrical supply store and it worked. Thanks for your help.

thanks4info...

I'm glad you were able to achieve a successful outcome with my
assistance. As indicated, I will therefore post a formal answer
to close the question, summarizing from our dialogue:

------------------------------------------------------------

You could probably get an electrician to install a 'rheostat'
or 'potentiometer' for a reasonable fee. A rheostat or 
potentiometer is basically a variable resistor used to change
the voltage or current delivered to an appliance.

A rheostat or potentiometer would be available from
an electrical supply store, or perhaps even Home Depot.

It would be the same as a variable speed control. It all
depends on the application. The lighting dimmer mentioned
by hlabadie-ga is a typical example, though you will need
a higher-rated one. The formula is Watts = Amps x Volts,
so a dimmer switch operating 4 60-watt bulbs would have
to handle 240 watts/110 volts = 2.182 amps. Yours needs
to handle 4.3 amps. At 110 volts, that's 473 watts. You
may find that the potentiometer you need is rated in watts
rather than amps, in which case you should find one that
is rated for at least 500 watts, since, at 115 volts, the 
wattage would be 494.5, and at 120 volts it would be 516.

An electrician should be able to locate the proper unit,
but if you plan to install it yourself (perhaps with 
guidance from the staff at Home Depot), the information 
above should be all you need to work with.

This is not the sort of item I would risk buying over 
the internet, sight unseen. The page you referenced 
doesn't have a picture of the FS5F, nor do I see a 
wattage or amperage rating. Personally, I prefer to 
deal with a human being to help me narrow down the 
best device with the appropriate rating for the task.
Buying an item like this over the net is more of a 
hit-or-miss proposition, and returning the item if 
it's not just right would be potentially expensive 
and difficult.

Especially if you're going to do this yourself, you
may be better able to determine what will look good
and install more easily by seeing the units in a
store, where you have the option of returning them
easily if the installation doesn't work out.

I didn't need to search in regard to this topic, as
I was an Electronics Technician in the US Navy, and
am familiar with the subject.


Please do not rate this answer until you are satisfied that
the answer cannot be improved upon by way of a dialog
established through the 'Request for Clarification' process.

sublime1-ga

You would be familiar with a rheostat in the form of a "dimmer"
switch, used to gradually raise or lower the intensity of a room
light, or on any ordinary three speed (high-medium-low) window or
table fan.

hlabadie-ga

thanks4info-ga:

Depending on where you plan on mounting the speed control/switch, this
might do the trick for you:

http://www.growinglifestyle.com/article/s0/a245242.html

You should be able to source this through Home Depot, True Hardware,
and just about any other major hardware chain in North America. At a
rating of 5.0 A @ 120 VAC, it can handle your 4.3 A @ 120 VAC blower
motor. You will need to mount it in a wall-box of course.

A better option would be to contact an authorized Thermador dealer to
see if you can buy Thermador's variable-speed control instead; it is
equipped with a an adjustable minimum speed setting so that you cannot
go below a minimum exhaust air flow when you have the fan turned on.
Safer that way.

Regards,

aht-ga
Google Answers Researcher

This will probably do the trick as well:

http://www.acehardware.com/product/index.jsp?productId=1286893

Regards,

aht-ga
Google Answers Researcher

Be careful when making   ANY !!!!  modifications.  Warranty will be voided

To emphasise kitchenman's comments:  BE VERY CAREFUL!!.

It is very possible that the single speed motor CANNOT be varied in
speed.  If for instance it is what is called an "induction" motor, it
will run at constant speed until the rheostat cuts the voltage so much
that the motor simply stalls out.

Also, if you are going to try using an electronic rheostat, check the
plate on the motor.  It will list the power consumption of that motor
in watts.  The rheostat should handle at the very least that much
power and preferably two or more times that power for reliability.