Does anyone know about home AC?
 

I just got a new fan motor. My old motor indicated 5MF. The new one indicated 7.5MF 370v. So, I am looking for a new Capacitor.

On my old capacitor it said 440v. My question is if I have to find exact 440v or 440/370v is ok?

I found these, below. Prices can be more than twice diff.
Thanks.

https://www.grainger.com/product/DAYTON-Motor-Dual-Run-Capacitor-Round-2MEJ8

https://www.grainger.com/product/TITAN-PRO-Motor-Dual-Run-Capacitor-Round-30D643?opr=PDPRRDSP&analytics=dsrrItems_2MEJ8

https://www.supplyhouse.com/Titan-Pro-TRCFD4075-40-7-5-MFD-Round-Dual-Motor-Run-Capacitor-440-370V?utm_source=google_ad&utm_medium=Shopping_tm&u tm_campaign=Shopping_TM_New_users&gclid=EAIaIQobCh MIrangmKXI_QIV6w6tBh2MvwXBEAQYASABEgKGwPD_BwE

This one is the same Titan HD, same as the Titan Pro above but twice the price. Does anyone know what is the diff between Pro and HD?

https://www.supplyhouse.com/Titan-HD-PRCFD4075A-40-7-5-MFD-Round-Dual-Motor-Run-Capacitor-440-370V?utm_source=google_ad&utm_medium=Shopping_tm&u tm_campaign=Shopping_TM_New_users&gclid=EAIaIQobCh MIrangmKXI_QIV6w6tBh2MvwXBEAQYAyABEgKaovD_BwE

Two of those appear to be the exact same part. Part # and everything. One is twice the price. Same part.

Does size matter? If one is longer and thinner, will it still fit?

Pretty sure that means dual voltage

The 440/370v will work. Does it spec a temp? Notice the first one is 85c and the second is 70c max temp, better quality usually are rated at higher temp range. Likely 70c will be good for ac motor.

My old capacitor is
440v
40/5 MF
70C.
The only diff I see is the cheap one indicates 440v/370v. I wonder if anyone knows for sure if it is ok or not. If it's ok, then it's $9 instead of $30....
I really wonder $9 instead of $30. There must be a diff huh :)

https://brobible.com/wp-content/uplo...t-she-said.jpg

:D :D :)
no it doesn't matter. I have a lot of room in that corner
I guess 440v is for the compressor. 370v is for the fan motor. Make sense right?

... the Titan pro is the 440/370v, but why it says this:
"Flexible: Titan PRO 440/370 volt design reduces inventory and Titan PRO 370 volt offers best in class value"??

Try to find a capacitor made in the USA. Failing that, find one made in Mexico. Don’t buy one made in China.

ok. I'll look more
even the grainger unit $30 is made in china :(
ah, the diff between the Titan PRO and Titan HD is that PRO is China made, HD is USA made. Probably not made, but at least assemble?

Take a look at Cornell Dobilier AC capacitor application guide if you want to understand what you are purchasing.

sold!!!

I think what they’re doing is using one side of the cap for the run circuit of the compressor and the other run side for the fan motor. The compressor needs a start/run cap to operate. The start side gives the compressor extra “umphf” to help overcome the load imposed on it, once compressor comes up to speed, a centrifugal switch in the compressor motor takes the start side out of the circuit and the run side stays in the circuit continuously to help clean up voltage spikes. You only need a run cap for the fan motor as there’s no load on startup of the fan. You can use a higher rated can say 550@70 mic, but not a lower rated one as it’ll burn up. If you can find a run cap with only one value instead of two like you’re looking at, it’s all you need. I’ve bought run caps for less than $10 bucks at a hvac supply house. Hope this helps…

908/930, thanks bro. but I hope i skip the deep learning on this task :D. I think I am going to for the Titan HD for peace of mind.

thanks masraum, yep done.

Thanks everyone.

it is a fan motor almost any cap will spin it

now the compressor is a bit different as you can't see it
and every one said can't fix a compressor all sealed up

long ago when without a/c but with a stack of busted units as an appliance repair school
a welding shop on one side and a motor rewinding shop on the other
we opened one just to look see borrowed a grinder from the welders
guess what there was a piston pump
power by a

FAN MOTOR

with a burnt wire
so rewind guys can you fix it
sure
hey welders can you seal it back up
sure
we did 5
4 worked one had a bad pump
welder got one rewind guy also
and we had two in our shop

should have done that but never did

anyway just got a deal on part full f-22 in tanks at 10% of whole sale at the flea
put leak stop in my king valve had a leak with UV dye and gassed it up
and my a/c is back up cooling the house

btw propane is a good a/c gas just not approved by big brother
just get non- arcing or sparking relays

Good that you can rebuild your compressor.
Thanks Nota

This is one of those parts where you buy two now, and have a spare at all times.

Like a plumbing shut-off valves, teflon tape, superglue, cut-off wheels, sawzall blades, 3" deck screws, etc.

btw the volts on a cap capacitor is a max safe load rate
not anything to do with the volts the unit operates at
your unit runs on 120 or 240 volts any rating higher is fine like 370 or 440
just the microfarad rate should be close exact if you can

A microfarad is a term to describe a capacitor's level of capacity. That means the higher the microfarad rating, the more electrical current it can store. A typical capacitor can range from 5MFD to 80MFD. If you are looking at your capacitor and you can't find the proper rating, it might also look like µF also.

more is better up until the smoke gets out but exact is safe on a cap microfarad rate

Also caps are a thing that actually wears out. Lifetime doubles for every 10f increase in temp rating. The price difference for one capacitor is insignificant compared to the hassle of repair so always buy the highest temp rated you can find.