Heat dispation of large current solid state relays
Heat dispation of large current solid state relays
(OP)
I have 400 VAC 30 to 80 Amp aplication (the solid state is rated 600 VAC 125 Amp) Which I plan to use with 3 (phase) resistance furnaces (5 heat treatment furnaces).
Since I have refrigerated coolant (24°C)already going to the furnaces, I would like to use fluid cooled heat sinks.
The supplier recommends 0.14 K/W (+ fan) heat sink.
I found "Fisher Elektronik" fluid coolers they show the heat disipation on a graf on one side Q[W] on the other Vw[l/h], based on a 26°c inlet.
with values which vary from 1200 to 2200 Q[W]
How do I calculate or convert these values to see if the dispation is sufficent.
How is it possible that fan cooled heat sinks seem to disipate more heat than fluid cooled ones?
If you know a better fluid heat sink supplier, or a little conversion program pls inform me.
Best regards
Billy
Since I have refrigerated coolant (24°C)already going to the furnaces, I would like to use fluid cooled heat sinks.
The supplier recommends 0.14 K/W (+ fan) heat sink.
I found "Fisher Elektronik" fluid coolers they show the heat disipation on a graf on one side Q[W] on the other Vw[l/h], based on a 26°c inlet.
with values which vary from 1200 to 2200 Q[W]
How do I calculate or convert these values to see if the dispation is sufficent.
How is it possible that fan cooled heat sinks seem to disipate more heat than fluid cooled ones?
If you know a better fluid heat sink supplier, or a little conversion program pls inform me.
Best regards
Billy





RE: Heat dispation of large current solid state relays
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You should be able to get a thermal resistance far below 0.14W/K with a liquid cooled heatsink.
You should be able to calculate your losses in the SSR for your operating condition, or the SSR datsheet will give worst-case losses for FLC. The alternative method is to work back from the maximum acceptable die temperature for the silicon assuming you have data for the thermal resistance of the SSR package and determine the maximum acceptable thermal resistance for the heatsink. Can you post a link to the SSR data sheet? That would help a lot.
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Sometimes I only open my mouth to swap feet...
RE: Heat dispation of large current solid state relays
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or
http://www
Or Wakefield.
http
Both these sites will have a technical section for calculations too.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Heat dispation of large current solid state relays
Thanks for your support.
Billy
RE: Heat dispation of large current solid state relays
htt
or
http://www.wakefield.com/pdf/thermal_tutorial.pdf
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Heat dispation of large current solid state relays