4 ms·
I highly recommend people who live in hot environments to keep a spare capacitor on hand. Even if you know how to fix it, if the AC dies when your local HVAC su
by SOLAR_FIELDS 2y ago
I highly recommend people who live in hot environments to keep a spare capacitor on hand. Even if you know how to fix it, if the AC dies when your local HVAC supply store is closed (eg not between 7am-7pm Monday through Saturday usually) you’re either stuck paying out the nose to a contractor who has one on hand during emergency hours or you’re sweating it out waiting for the store to open. While they are readily available components that consumers can purchase, they aren’t things that Walmart carries. But HVAC supply shops will sell them to you, you don’t need to be licensed or anything to buy them. You can also just get them on Amazon, likely for cheaper than the HVAC supply shop will sell them to you.
It really is an easy repair. Needs a screwdriver and knowledge enough to shut off the electricity to touch the wires. According to code every one of these condenser units outside has a disconnect right there so you don’t even need to turn off the power at the breaker box. Just pull that disconnect, open up your outdoor condenser unit, snap a pic of the specs on the capacitor (it’s the only thing that looks like a soda can) and order one off Amazon and stash it somewhere. It’s a tiny part. It will take like 5 minutes max and save you several hundred bucks and a lot of sweat eventually.
FWIW, when ac dies it’s usually in this order of root causes:
Float switch: your condensate drain line got clogged because it just does and you need to clear it. You can proactively prevent this by pouring bleach or vinegar down the line periodically (what clogs it is usually some sort of gnarly plant like growth from all the moisture) or if it’s clogged you need to clear it. The hvac guys will charge you 300 bucks to blow pressurized air through the pipe or you can literally just duct tape a wet shop vac to the thing and suck it out yourself. Attachments can be purchased on Amazon for reasonable price.
A capacitor issue is the second most common. If it ain’t the float switch almost always it’s the capacitor. You can increase your capacitor longevity and also decrease your electric bill by changing your air filter regularly but also hosing down the outside condenser coils every few months or so. Almost everyone knows about the air filter but few people know about hosing down the coils. This makes a HUGE difference. We are talking like 20-30% of your electric bill in hot climates if you don’t do it. Just take a hose and spray downward on the grates and get all that dust and dead grass from mowing out of there. You won’t hurt the thing. Why does this help? Well, it’s better to think of AC not as adding cool air. There’s no such thing as adding cool air. Only removal of heat. How does heat get removed out of your house? Through that condenser unit. If those grates are clogged up the heat cannot escape and the unit must work harder to do less effective job. So keep those coils clean.
Everything else after that is way less common. Yeah compressors do die. Motors die. Refrigerant leaks. Computer components die. Thermostats fail. However it’s very rare that the issue is something other than these two things in comparison. Like probably 80% of all HVAC residential calls are probably the above two things I mentioned.
- biggc 2y agoHow big can these capacitors be? Does replacing it require any safety precautions besides turning off the power?
- pxx 2y agothe capacitors are connected across the motor windings and are there essentially as a way to shift the phase of the current waveform. note that this is a two-phase power special; you don't need start or run capacitors if you're using 3-phase power (uncommon in North American residential settings, but YMMV worldwide) when power is disconnected they are not charged at all. it's not like the capacitors you might find in a CRT
- rocqua 2y agoSo what you are saying is that the capacitors are effectively shorted with the motor coil, and hence they have a drain resistor that has effectively no resistance?
- deleted 2y ago[deleted]
- SOLAR_FIELDS 2y agoThe capacitors size themselves are small. They slightly vary but are almost always the size of a medium Red Bull can. They are sized to your unit though so you can’t just buy one without looking at the specs and expect it to work. But the specs are printed on the side of the can and if not can be derived from the specs on the unit itself. As far as their danger there really isn’t any beyond getting shocked from dealing with live wires. Technically they can retain a bit of a charge so I’ve seen recommendations to wait X amount of time before touching them with your bare hands or to discharge it by touching it with an insulated screwdriver to discharge it but the risk is pretty low. Once the power is off (either at the breaker or via the disconnect at the condenser unit, power only goes in one way to those things so if you turn it off in one place there’s no way you’ll get a zap) it’s a soda can with 3 wires going into it. You just disconnect the 3 wires from the old soda can, remove it, replace and connect the new one. Not that much harder than changing a light bulb.