Tomm,
Yes, it sure does. I have done that in the past, and even snaked a temp wire
into a coil when winding it then pulled it out later on. The hottest spot in
each coil is in its center and mid ways of each coil. This being for the
primary and each scecondary. The coolest coil will be the outer one, and the
hottest closest to the core. There is a long drawn out formula to supposedly
determine this where you use the thickness of the insulation between layers and
between each coil along with the hot resistance. I found though that it isn't
as exact as they say it is because there's just too many variables involved,
and one coil can be different than another even though the math says it's not
so. What I'm wanting to do is get a good average of temp say for one model
transformer. There are some purchasers who want to know the hottest a
transformer will get including using the temperature of the enviroment where it
is to be installed. I found that using the temp estimating formula just
dont jive with the real world though, and am looking for ways to measure this
and get a good average. Then new designs can be built using this data to where
it would be more thruthful in what the actual loaded temp is. I'm writing a
transformer program to calculate power transformers, and the temp part I'm
wanting to modify, or not include if I cant figure out the fudge factors. Any
ideas?
Best,
Will
*********** REPLY SEPARATOR ***********
On 1/29/06 at 4:29 AM KD7QAE wrote:
>Will,
>
>It would be much simpler to make a jig to load the xfmr and wait until
>the temp on the outside stabilized then switch over to an ohmmeter to
>read the hot resistance of the coil in question. Comparing the cold and
>hot resistance will give you a good average temp of the coil under
>test. knowing the outer temp is good because you can now do a simple
>estimation of hot spot by taking the difference between the average and
>the outer temp (assume it is the coolest) and add that to the average to
>get the hot spot temp. Make sense?
>
>Tomm
>
>Tomm
>
>Will Matney wrote:
>
>>We had discussed using the new infrared aimable thermometers for this.
>You aim the laser dot and read the temp. I was thinking Rich Measures was
>going to try this out using a Fluke model. If it was a sucess, I would
>like to know the outcome. I myself though of using one to check the coil
>temperatures on transformers running under full load. The outter coil temp
>can be used to extrapolate the internal temp at the mean radius of each
>coil this way. Has anyone tried this with any success yet?
>>
>>Best,
>>
>>Will
>>
>>
>>*********** REPLY SEPARATOR ***********
>>
>>On 1/28/06 at 8:00 PM Bill Turner wrote:
>>
>>
>>
>>>ORIGINAL MESSAGE:
>>>
>>>At 11:35 AM 1/28/2006, Gary Smith wrote:
>>>
>>>
>>>
>>>>Top of my one of my 3cx800 a7's reads 73 degree at idle in standby
>>>>Temp of tube key down 145 degrees. 1kw in rtty out.
>>>>
>>>>
>>>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>
>>>The top of the tube is not especially critical. It's the seal
>>>wherever metal meets glass or ceramic that counts. If you can reach
>>>that with the tube operating, fine. Many rigs you can't.
>>>
>>>73, Bill W6WRT
>>>_______________________________________________
>>>Amps mailing list
>>>Amps@contesting.com
>>>http://lists.contesting.com/mailman/listinfo/amps
>>>
>>>
>>
>>
>>
>>_______________________________________________
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>>
>>
>>
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