Electrolytic capacitor ESR confusion

[valley001]

I am in the process of recapping a Fluke 332D.  Once cap has failed on it so far and I would rather not chase bad caps over the next 10 years so I have decided to simply replace as many of the electrolytic as I can (reasonable?)

Three of the caps are 450v 8uf +50/-10%.  I found KEMET PEG124YF2100QL1 450v 10uf however the quoted ESR is 5.7 ohms.  Is this a normal ESR figure for this type of capacitor?  My noob impression is that ESR should be less than an ohm.  I just want to be sure I install a cap that will work properly.  Thanks in advance for the education. 

[helius]

High voltage, low capacitance devices have high ESR as a result of their physical construction. That is perfectly normal.
I would probably not replace all capacitors at once because there is a risk of damage with any kind of rework.

[valley001]

High voltage, low capacitance devices have high ESR as a result of their physical construction. That is perfectly normal.
I would probably not replace all capacitors at once because there is a risk of damage with any kind of rework.

Is this risk lower than a cap going sideways?  I worry about a sideways cap taking out other more unobtainable parts. 

[Jay_Diddy_B]

Hi,

Less than 1 is a simplification.

A lot of commonly encountered values will be less than 1 , but if you look at the Kemet datasheet:

https://www.mouser.ca/datasheet/2/212/KEM_A4011_PEG124-1104316.pdf

You will see that some low capacitance and higher voltage electrolytic capacitors are more than 1 ESR.

The Kemet part you have chosen is probably better than the part that was used originally.

Do you have a method foe measuring ESR?


Regards,

Jay_Diddy_B

[valley001]

Thanks everyone for chiming in.  I use one of those cheap component testers for measuring ESR.