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| Mountain_man Member Since: 09 Dec 2011 Location: Right side of Offas Dyke Posts: 756  
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After some advise for recommissioning my pressure washer. A while back I had problems with it constantly cutting out after a few minutes. I was able to cure this by removing the thermal cutoff which was something similar to one of these
http://www.ebay.co.uk/itm/KSD-9700-Tempera...188e6e93f# This cured the issue and all was great for a year or so until now I find the starter capacitor has broken down as a result of excessive heat. This was to be expected I guess and I can get another pretty easily. One of these in fact http://www.ebay.co.uk/itm/ITALFARAD-80uf-C...3aa2ba619f Obviously I would like to put the thermal protection back into the circuit but appear to have lost the one I removed. Now for the query. Does anyone have any idea for a good starting point for the cut off temperature to protect the motor in future since there appears to be a large range available i.e. 40-150 degrees? I don't want it constantly cutting out again but neither do I need another melted capacitor due to excess heat. I am thinking somewhere around 100-120 degrees might work. Has anyone got a more informed opinion? |
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17th Aug 2015 7:35pm |
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| Silver Back Member Since: 11 Jun 2015 Location: Lincolnshire Posts: 405  
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I would have thought 80 celsius would be a maximum. Above that and PVC insulation tends to break down and becomes less effective, potentially becoming dangerous with prolonged use.
Have you tried any web resources by the manufacturer? Sometimes their web sites have the original documentation which may have something listed in the machine's specification. |
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17th Aug 2015 7:41pm |
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| Mountain_man Member Since: 09 Dec 2011 Location: Right side of Offas Dyke Posts: 756
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Thanks fo rthe reply. I have done extensive web searches to no avail. I was kind of thinking about sitting in a sauna at 90 degrees and thought a plastic capacitor should surely be able to stand a bit more heat than me
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17th Aug 2015 7:49pm |
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| K9F Member Since: 12 Nov 2009 Location: Bournemouth Posts: 9610 
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80 uF Motor Start Capacitors can be had a hell of a lot cheaper than the one you linked. Not having the original thermal cut out you're stuffed really unless you have a circuit diagram for your washer or access to a diagram where the details may be shown. As above I would have thought ballpark 80 degrees would suffice. May be a trial and error process. I would buy a couple of capacitors Justin.....'just in' case.
 If you go through life with your head in the sand....all people will see is an ar5e!!
Treat every day as if it is your last....one day you will be right!! |
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17th Aug 2015 7:51pm |
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| apt100 Member Since: 05 Mar 2015 Location: Derbyshire Posts: 1547 
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According to the manufacturer, the max temp for that capacitor is 85C (which is a very common rating for caps etc), if that helps.
http://www.italfarad.com/menumotorieng.htm |
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17th Aug 2015 7:57pm |
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| Mountain_man Member Since: 09 Dec 2011 Location: Right side of Offas Dyke Posts: 756
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Thanks for that K9F
I have the original circuit diagram but it is very simple and has no details. HOWEVER I have just realised (via the power of google) that the 25/85/21 on the side of the capacitor means min temp -25, max temp 85 degrees and a damp heat duration test result of 21 days. So I guess both of you were spot on.
I have also found planty of 80UFs for sub £10 but linked to that one as it is the same model and size exactly as the one I removed. I am going to try a cheapo one and a new 85 degree thermal switch and see what happens. If it cuts out all the time I guess I can up the temp by 10 degrees and see how long it lasts this time Thanks for advice, much appreciated EDIT.... cheers for that, I had just reached the same conclusion |
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17th Aug 2015 7:57pm |
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| Mountain_man Member Since: 09 Dec 2011 Location: Right side of Offas Dyke Posts: 756
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Nope, it is 90 degrees C in a sauna.
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17th Aug 2015 8:15pm |
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