Help with correct capacitor size for home HVAC -- Lenox and Carrier

[cninham]

Can someone please help me verify the correct capacity for the motor run capacitor for two HVAC units that I have, please? I believe the AC service technician replaced BOTH units with the WRONG capacitor size.

AC Unit # 1

Lenox 10HPB42-11P

Capacitor – I believe this should be a 40+5 MFD capacitor

Service technician installed a 50+7.5 MFD capacitor

AC Unit # 2

Carrier

Prod: 38CKC048-371

Model: 38CKC048370 / 38CKC48370 / 38CK048370 (???)

Capacitor – I believe this should be a 40+5 MFD capacitor

Service technician installed a 40+3 MFD capacitor

Thank you,

Cameron

[RegUS_PatOff]

Fan Motor Capacitor rating is dependent on actual Fan Motor installed.

[cninham]

Thank you for the reply -- in both cases the fan motor is the original motor and the AC unit is "standard" with nothing changed.

Any idea where I can get the capacitor information from, please?

Thanks -- Cameron

[jumptrout]

The fan motor will have the cap rating printed on it.

[cninham]

Thanks -- I got the fan motor capacity rating from the motor as suggested.

How do I get the compressor (HERM) capacitor rating?

Cameron

[RegUS_PatOff]

my research finds:

AC Unit # 1

Lennox 10HPB42-11P

80K48 40/5 440v

AC Unit # 2

Carrier

38CKC048370

P291-5054RS 50/5 440v

[cninham]

Thank you! Very much appreciated!

On the 2nd unit, the Carrier, Prod: 38CKC048-371, Model: 38CKC048370, I have received conflicting information. Some other forums have stated the capacitor to be:

45+5 MFD, 440 VAC

Would the discrepancy/difference between the two matter? Is it safer to go with the 45+5 or 50+5 MFD...?

Thanks -- Cameron

[RegUS_PatOff]

+- 10% should be OK .

.38CKC048370 P291-5054RS

http://parts.sears.c...CKC048SERIES370

[jumptrout]

The 10% mentioned by Reg is good info.

The real important part is the 370vac/440vac capacitor.

Any system can run fine with a 440vac.

If a system specifies 440vac it will not run correctly on a 370vac.

[cninham]

Again, THANK YOU to everyone for your information and help. It is very much appreciated.

Cameron

[m_west5]

I know this is an old posting, but may help someone else reading it.  It's a pain to do, but to be absolutely sure of the capacitance for the compressor, you could remove fan from top of condenser unit and look at the sticker on the compressor. Most Copeland scrolls (very common) and other mfg's have the cap rating on this sticker.

 

Hope this helps.