Do capacitors and transformers have a shelf life?

[hal1]

Last year when my AC went out (the fan worked but no action from the condenser outside) I figured, what the heck, lets run down to ACE and pickup a capacitor, figuring that if it wasn't the capacitor then it wasn't something I was going to be able to fix myself anyway. (yes, I know of the precautions about capacitors). - Bamm, perfect, a $17 fix for what Acme HVAC would have charge me $250 to come out for.

So now, knowing how cruel Phoenix summers are to A/C components, I got a spare capacitor. I was thinking the same thing about getting a spare transformer to have on hand too.

So, do capacitors and transformers have a shelf life? I figured, for $17 each, can't hurt

 

[cvairwerks]

Sorta...depends on types and storage conditions. Cool and dry helps transformers, as heat can degrade the varnishes on the windings as well as the wire coatings. Heat is detrimental to any caps other than some of the mica caps and large industrial caps.

Neither item survives getting submerged or being wetted down often.

 

[hal1]

Sorta...depends on types and storage conditions. Cool and dry helps transformers, as heat can degrade the varnishes on the windings as well as the wire coatings. Heat is detrimental to any caps other than some of the mica caps and large industrial caps.

Neither item survives getting submerged or being wetted down often.

Short version - yes, I can keep spares stored inside, should be good for a few years? Heck if they work for 5 years outside and in the attic they could be good in my closet?

 

[cvairwerks]

Short version - yes, I can keep spares stored inside, should be good for a few years? Heck if they work for 5 years outside and in the attic they could be good in my closet?

Yep... I've got to replace all the caps in one of my radios....paper and electrolytics that are almost 70 years old and leaking and off spec. 5 years isn't anything timewise....

 

[karoc]

Don't condemn company for trying to employ people, pay overhead and maybe even provide insurance. I don't know any successful business that could make it without making a profit. Keep in mind that a company who makes a profit will be your most honest company. By the way if your parts are keep in a climate control environment then they stand a better chance of lasting for ever

 

[hal1]

By the way if your parts are keep in a climate control environment then they stand a better chance of lasting for ever

i was re-thinking my question and then thought of the obvious (to me). If a capacitor or transformer will work under conditions for 5-10 years, why wouldn't those same components keep their useful life when properly stored? Unless they somehow deteriorate when not in use?

 

[Dagny]

it isn't anything to worry about. The capacitors from china are ****.

 

[elderstarr]

If you're paying $250 for a capacitor replacement, find a new HVAC company.

We charge $154 Canadian after tax.

 

[karoc]

i was re-thinking my question and then thought of the obvious (to me). If a capacitor or transformer will work under conditions for 5-10 years, why wouldn't those same components keep their useful life when properly stored? Unless they somehow deteriorate when not in use?

Good point, I have several caps that are several yrs old which are getting kinda corroded on outside and some can’t read what MFD they are but I just can’t make myself toss them. Ones that still in box I have them stored in Tupperware with lid. Elec motors that’s another story

 

[BillK]

We charge $154 Canadian after tax.

Just curious how you can possibly make a profit at that price ?

 

[Terry D]

Last year when my AC went out (the fan worked but no action from the condenser outside) I figured, what the heck, lets run down to ACE and pickup a capacitor, figuring that if it wasn't the capacitor then it wasn't something I was going to be able to fix myself anyway. (yes, I know of the precautions about capacitors). - Bamm, perfect, a $17 fix for what Acme HVAC would have charge me $250 to come out for.

So now, knowing how cruel Phoenix summers are to A/C components, I got a spare capacitor. I was thinking the same thing about getting a spare transformer to have on hand too.

So, do capacitors and transformers have a shelf life? I figured, for $17 each, can't hurt

If you are talking about just buying some spares and storing them on a shelf, I would think they would be just as good 20 years from now. I have some NOS transformers that was in my fathers stash, I know they are at least 30 years old. They still work fine. But then again, they weren't made in China back then.

 

[elderstarr]

Just curious how you can possibly make a profit at that price ?

Because we're not a big company with a huge amount of overhead.
No brand new, fully wrapped Mercedes vans.
No fancy shop. (We share one with a Tinsmith company).
5 stars on Google, word of mouth advertising, and cheaper prices than the competitors keep us busy and profitable enough.

Don't overlook the small companies.

 

[Snip]

If you're paying $250 for a capacitor replacement, find a new HVAC company.

We charge $154 Canadian after tax.

last 4th of july weekend we had the on call HVAC guy out to fix the A/C, bad capacitor. Total bill was only about 165,( Thought this was very reasonable and their card is on the front of the fridge) this was on a Holiday Sunday. I saved the box for the numbers......I have a spare now

 

[theoldwizard1]

Sorta...depends on types and storage conditions. Cool and dry helps transformers, as heat can degrade the varnishes on the windings as well as the wire coatings.

Oh come on ! The varnish/epoxy on a transformer is good for over 200F !

 

[cvairwerks]

Oh come on ! The varnish/epoxy on a transformer is good for over 200F !

Haven't found one yet that's not in a oil bath that won't get rusty and start splitting the laminations if it's stored where there is too much humidity and too low airflow.

Got a couple of radios over in storage that the transformers are blocks of rust and the old time WW2 age varnish has begun cracking.

 

[rburke65]

well definitely capacitors will start to leak and need replaced at some time.

 

[Jeepster04]

The inside unit has a cap in it also.

 

[n8n]

Electrolytic capacitors definitely have a finite lifespan, after 20-30 years or so they need to be replaced (my experiences with stereo equipment and speaker crossovers) I think those HVAC caps are paper in oil though which last a lot longer, so keeping one on the shelf shouldn't hurt.

 

[acmikee]

i've had capacitors and transformers roll around in my service trucks for years without any issues..

 

[dogdog]

No shelf life for transformers. unless you let the environment/elements gets to it.

capacitor unless you let the electrolyte dries out or some how it develop a short between plates.

 

[Farmall450]

Oh come on ! The varnish/epoxy on a transformer is good for over 200F !

Yeah, I think if it can run in an A/C unit for 10-20 years in 100+ degree weather (not to mentioned heat built up in the unit when the fan is off) I don't think your house's 69 degrees is giong to hurt it lol