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Burning up Condenser

Posted: Fri May 01, 2020 4:57 pm
by Josh.bedell
(Sorry for the delay, Josh! Cal_Gary)

My truck keeps burning up Condensers. What should the voltage be set to?I can't find it in my manuals.

Re: Burning up Condenser

Posted: Mon May 11, 2020 10:08 pm
by Kaegi
are they chinese? its about 50/50 they work more than 20 miles anymore. I would try to find NOS. old condensers and a long piece of copper sheet metal insulated with paper then inside filled with resin. they new ones are one tiny finger nail size piece of copper floating in resin. total joke.

Re: Burning up Condenser

Posted: Wed May 13, 2020 10:34 am
by HingsingM37
I have found that even the NAPA points and condenser sets along with distributor caps for various applications have diminished in quality. Hard to find decent old school tune up parts. I guess the demand just isn't there anymore to rate anything more than cheap imports.
I recommend the Pertronix kit. I have been running mine 8 years no issues.

Re: Burning up Condenser

Posted: Wed May 13, 2020 2:42 pm
by RMS
you could also cram two 12v condensers in there if you cant find a decent 24v. cap would need a bit of clearancing to fit

Re: Burning up Condenser

Posted: Wed May 13, 2020 6:04 pm
by John Mc
RMS wrote:you could also cram two 12v condensers in there if you cant find a decent 24v. cap would need a bit of clearancing to fit
If you are nosing around for a replacement, the modern term for a condenser is a capacitor, though both terms are still used.

There is a decent chance that condenser from a 12 V vehicle is already rated for a lot more than 12 volts (the rating may be noted on the condenser). The key is to get one with a voltage equal to or higher than the original and a capacitance of equal value to the original (usually measured in microfarads (abbreviated mfd or uF) or picofarads (pF). Adding two capacitors in parallel does nothing to their voltage rating, but it does add their capacitance together (a 100 volt 10 mfd capacitor in parallel with a 100 volt 50 mfd capacitor gives you the equivalent of a 100 volt 60 mfd capacitor).

NOTE: if you connect two capacitors in series, the total capacitance will be LESS THAN the smallest of the two series capacitors. (Using the numbers from the example above, a 10 mfd and a 50 mfd capacitor connected in series is the equivalent of an 8.33 mfd capacitor.) They can handle more voltage this way, but I forget the formula for calculating that. The calculation gets a little funky if the two have different capacitances.

Re: Burning up Condenser

Posted: Thu May 14, 2020 1:21 am
by just me
Funny we are discussing capacitors here. I'm working on a system today that appears to be a failing (internally grounded) capacitor. Only difference is it is a 14.4 milliFarad capacitor! (Biggest one I've had to deal with) only weighs 300 lbs.

Re: Burning up Condenser

Posted: Thu May 14, 2020 5:55 am
by John Mc
just me wrote:Funny we are discussing capacitors here. I'm working on a system today that appears to be a failing (internally grounded) capacitor. Only difference is it is a 14.4 milliFarad capacitor! (Biggest one I've had to deal with) only weighs 300 lbs.
Is that some power factor correction capacitor in some industrial application that had a lot of inductive loads?

Don't you wonder how we ended up with a unit of measure so big that all most anyone sees in normal use his micro (one millionth) and pico (one millionth of a millionth) versions of that unit?

Re: Burning up Condenser

Posted: Thu May 14, 2020 12:18 pm
by just me
Well, a coulomb is fairly stout also. And since the two are related 1 to 1 it stands to reason. The weird thing is they when they were first described.
Some pretty smart feller's back then.

Re: Burning up Condenser

Posted: Fri May 15, 2020 4:50 am
by just me
It is the DC Link capacitor in a traction inverter for a Light Rail Vehicle.

Re: Burning up Condenser

Posted: Sat May 16, 2020 7:04 pm
by Josh.bedell
Thank you everybody for the input. I'm thinking over the 2 12 volt capacitors and the pertronix system.

Re: Burning up Condenser

Posted: Tue Jun 02, 2020 4:05 pm
by PoW
Two like-value caps in series will give only half the capacitance value of one. Your points will suffer, if not the overall running.

All ignition caps are made to withstand much higher voltages than found in any vehicle electrical system so don't worry about that part.

PoW

Re: Burning up Condenser

Posted: Wed Jun 03, 2020 3:00 am
by NAM VET
when I had my truck worked on a year ago up in NC, at Charles Talbert's shop, one of the things he did was to put in a Pertronix. I never want to have to pull my distributor again, nor have to work down in that chasm to fiddle with it. Works for me. HC

Re: Burning up Condenser

Posted: Sat Jul 11, 2020 11:40 pm
by QCIM37CDN
RMS wrote:you could also cram two 12v condensers in there if you cant find a decent 24v. cap would need a bit of clearancing to fit
:?: They aren't 24 volt condensers, the M37 shares its condenser with several other 6-12-24 volt applications. When guys convert a civvy power wagon from 6 to 12 volts, the condenser stays the same. The M38 jeep (24v) shares its condenser with the 6v CJ's, as well as the M37. They aren't a voltage specific item, and the old ones rarely fail. New ones are crap, but you can easily find NOS ones on eBay.