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United States - Member - Donald here, Campbell Lighting Co. Engineering Fields - Retired Engineers / Mentors - New Member

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52 Mfd Capacitors

03/06/2008 12:50 AM

I have a fairly large quantity of Dry film type 52 uf power factor correcting capacitors that make a loud hummmmmmmmmmmm..

These were a manufacturing error, and Thank God they replaced them with quiet ones..

Now, it seems a shame to just throw em out, I mean they all work, they are just loud.

I figured people could use these where the sound wouldn't bother anything, like outdoor lighting wall-packs: (these 52 uf can be used on 100 and 150 watt HPS to reduce the amperage in half.

Also, what's all this talk about "Capactor Banks" Could these be used for that purpose?

Just wondering, as I am sitting on 2000 pc of perfectly working, loud capacitors, and I have No use for them in my light fixtures

Donald

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#1

Re: 52 mfd capacitors

03/06/2008 5:22 AM

Hello Campbell Lighting

The reason the factory replaced those capacitors is that they were faulty.

In my experience, noisy capacitors mean that there is something incorrect inside.

Whatever the actual fault, because they are noisy, means vibration internally to create the noise you can easily hear, outside the capacitor container.

Vibration = Mechanical work = Heat and fatigue fracture early in the life of the capacitor, which the factory knows.

That's why you got those free replacement capacitors from the makers or their distributors..

Sure they seem OK, apart from the loud buzzing, but that is not what it's all about.

Now I'm wondering why the factory or distributor did not, as a condition of supply of replacements, insist the faulty units be sent back to them or their distributor, at the Cost to the Factory, because that is normal procedure, to prevent such action as you are proposing.

Now I know everyone likes a bargain, but if you sell or give away those capacitors, one or more may eventually explode, with consequences of equipment damage or personal injury.

I'm sure you would not want to be responsible for any accident resultant from your selling or giving those capacitors away, would you.talk to the factory, explain that you want to return the faulty units, at their cost, and if they value their reputation, they will be eager to pay freight, and receive back, those faulty capacitors.

After all, they don't want to be embroiled in a large Lawsuit, if something goes wrong later, do they.

Kind Regards....

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#3
In reply to #1

Re: 52 mfd capacitors

03/06/2008 2:03 PM

Hello...

I really appreciate that warning for sure!

Actually we have used this exact type of capacitor in over 100,000 light fixtures, and some caps were louder than others, and we have never had a single capacitor blow up.

I have seen many small capacitors blow out, and sounded like a small firecracker.

This might be a great new topic, how capacitors fail..

As a matter of fact, we have been selling light fixtures of this same style for 19 years now, and I cannot honestly say we have ever had a single capacitor failure, much less had one explode.

Thanks Donald

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#2

Re: 52 Mfd Capacitors

03/06/2008 8:49 AM

That's a great answer. I've seen a cap blow up that was humming. I don't know what the electrolite is made of, but I'm s ure I don't want it on me.

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#4

Re: 52 Mfd Capacitors

03/07/2008 4:45 AM

You could make a big humming machine.

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#5

Re: 52 Mfd Capacitors

03/07/2008 10:16 AM

I've only seen caps explode when they experience an overvoltage of large proportions. I think it's because of the static forces at work inside the cap. However as mentioned before if the plates inside are moving, the dielectric material(s) could easily fail thus creating a short circuit inside. I'm sure there are many other ways they could fail but the ones I've seen aren't pretty. I'll bet the company replaced those caps because they have a high failure rate and it will cost the company much less to replace the caps instead of paying for litigation.

On the bright side you might be able to sell the metal inside the caps for a good price!?

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