AC capacitor question

barnacle bob

Joined: Oct 25, 2011

User Profile Ignore User Stop Ignoring

How long do you want to ignore this user?

24 hours One week Permanently Cancel

I'm trying to order a spare run capacitor. Having a hard time finding exact match.

The current unit has +/- 10% tolerance. How critical is that? 6% is as close as I can find.

BenTheGoodAg

Joined: Aug 20, 2014

User Profile Ignore User Stop Ignoring

How long do you want to ignore this user?

24 hours One week Permanently Cancel

11:00a, 3/11/23

+/- 6% tolerance is better. Go for it.

Needs to be said - Make sure you discharge before touching the old one if it's still in there. There are some good videos, but watch a couple of them.

Cromagnum

Joined: Sep 3, 2007

User Profile Ignore User Stop Ignoring

How long do you want to ignore this user?

24 hours One week Permanently Cancel

6:03p, 3/11/23

Getting a bigger capacity one works great as long as it physically fits the space the old one did. More startup energy.

BrazosDog02

Joined: Oct 17, 2002

User Profile Ignore User Stop Ignoring

How long do you want to ignore this user?

24 hours One week Permanently Cancel

9:07p, 3/11/23

You can see if it's discharged the same way you check a 9V battery to see if it's good.

Just give it a lick.

(Ok, I'm kidding. Don't do this.)

Animal Eight 84

Joined: Sep 15, 2021

User Profile Ignore User Stop Ignoring

How long do you want to ignore this user?

24 hours One week Permanently Cancel

6:18a, 3/12/23

April 1 is coming up.
Just slip that charged cap into a buddy's jacket pocket that's hanging up.
At the end of the day he will put on his jacket, feel the weight and reach his hand into the pocket…..,.

Always good for a laugh.

1 edit

Texker

Joined: Dec 3, 2002

User Profile Ignore User Stop Ignoring

How long do you want to ignore this user?

24 hours One week Permanently Cancel

10:45a, 3/12/23

Don't overlook American made capacitors.

BenTheGoodAg

Joined: Aug 20, 2014

User Profile Ignore User Stop Ignoring

How long do you want to ignore this user?

24 hours One week Permanently Cancel

In reply to Cromagnum • 11:50a, 3/12/23

Cromagnum said:
Getting a bigger capacity one works great as long as it physically fits the space the old one did. More startup energy.

I would not do this... Buy the size the manufacturer recommends.

More start-up energy reduces winding life (and I think this is a run-capacitor, anyway). Don't reduce the life of the $500-1000 component to save money on the $10 capacitor.

javajaws

Joined: Dec 2, 2010

User Profile Ignore User Stop Ignoring

How long do you want to ignore this user?

24 hours One week Permanently Cancel

4:10p, 3/12/23

And if you keep blowing capacitors every year your motor is probably going bad. Make sure it spins freely when not under power.

Aggietaco

Joined: Aug 28, 2006

User Profile Ignore User Stop Ignoring

How long do you want to ignore this user?

24 hours One week Permanently Cancel

8:30a, 3/13/23

Considering that unit is a replacement, you might check to see what size the fan comes with from the factory.

Cromagnum

Joined: Sep 3, 2007

User Profile Ignore User Stop Ignoring

How long do you want to ignore this user?

24 hours One week Permanently Cancel

In reply to BenTheGoodAg • 1:03p, 3/13/23

BenTheGoodAg said:
Cromagnum said:
Getting a bigger capacity one works great as long as it physically fits the space the old one did. More startup energy.
I would not do this... Buy the size the manufacturer recommends.

More start-up energy reduces winding life (and I think this is a run-capacitor, anyway). Don't reduce the life of the $500-1000 component to save money on the $10 capacitor.

My startup fans went out 2x a piece on my home AC units until our AC tech installed slightly bigger capacitors. Trouble free for at least 5 years ever since.

UmustBKidding

Joined: Jun 13, 2011

User Profile Ignore User Stop Ignoring

How long do you want to ignore this user?

24 hours One week Permanently Cancel

In reply to Cromagnum • 4:18p, 3/13/23

What is your definition of bigger? Higher capacitance? Probably not, higher voltage rating, absolutely. Most are 370V 440vac. But some are lower. Also many like made in usa, but there is crap at least marked usa. The $7 one may have had its quality leak out before you opened the box.