Ask Me Help Desk - Fab Motor Wiring

This is almost a redundant question but not quite. My old motor had 3-wires, black to contactor, brown to capacitor, purple to DF2 on circuit board. The old capacitor only has one spade terminal for fan, but four for herm and common. They said to wire-nut brown/white wire, connect black to contactor and brown to fan terminal on capacitor, and white to DF2 on board.
Doesn't this mean I will have to buy another capacitor to replace the old one for the compressor? That's what I thought I was doing. There is only one capacitor,
The motor schematic says to connect black and white to line, which I understand, but it says to connect capacitor with brown and brown/white on opposite terminals of capacitor. The new capacitor has 4 spades on fan, common, and herm terminals. Any second opinions? Thanks...

One capacitor wire to fan connection on the dual value capacitor the other to common. Common is common for both the fan and compressor. If you are installing a new fan motor you need to check to be sure the old capacitor values are the same as for the new motor. If not you will need to buy a new fan capacitor of the correct value for the new motor.. I always made it a habit of using a new fan capacitor any time I installed a new motor no matter what the old capacitor said. Capacitors do not last forever.

On the dual start-run capacitors, the herm terminal is for the compressor. The fan terminal is marked and C or com is the common. HVAC1000 is telling you that you need to look at the motor label and see what cap is required. You may need to add the correct cap. Leave the one that's there for the compressor and add the new one if you need to.

Quote:

Originally Posted by hvac1000

One capacitor wire to fan connection on the dual value capacitor the other to common. Common is common for both the fan and compressor. If you are installing a new fan motor you need to check to be sure the old capacitor values are the same as for the new motor. If not you will need to buy a new fan capacitor of the correct value for the new motor..I always made it a habit of using a new fan capacitor any time I installed a new motor no matter what the old capacitor said. Capacitors do not last forever.

Yes it is the cap that the company advised me to use with that motor. So I will see if I can use the new cap in place of the old one. If the wiring doesn't work out, I will have to buy a new one for the compressor too. Yes, it is a 5/35 mfd like the old one, but is it rated at 370/440 and the old one is just a 370 volt, but I don't think that matters, just the 5/35mfd. I think I understand correctly now. I thought if the old system had only one start run cap for compressor and fan motors, you could only have one. I guess you could have two no problem. Both motors will have a new cap now.

Thanks for the second opinions

Great ! Yes, you can run them individually. It might be a good idea to do that anyway. The dual ones are more expensive to replace anyway. Glad you got it down. My AC went haywire last week and 2 different techs couldn't or wouldn't solve the problem. Time delay switch was acting up. Finally just bypassed the thing and let the built in time delay in the t-stat do the job. At least I know my freon level is good. LOL Sometimes, I think common sense is more valuable than a certificate. One tech told me to replace the t-stat and the other said to put rubber pads under the unit. Unbelievable!! Anyway, that's why I am here. To bounce ideas around. Who knows, we might actually get something to work ?

Quote:

Originally Posted by westnlas

Great ! Yes, you can run them individually. It might be a good idea to do that anyway. The dual ones are more expensive to replace anyway. Glad you got it down. My AC went haywire last week and 2 different techs couldn't or wouldn't solve the problem. Time delay switch was acting up. Finally just bypassed the thing and let the built in time delay in the t-stat do the job. At least I know my freon level is good. LOL Sometimes, I think common sense is more valuable than a certificate. One tech told me to replace the t-stat and the other said to put rubber pads under the unit. Unbelievable !!! Anyway, that's why I am here. To bounce ideas around. Who knows, we might actually get something to work ?

Well, I have been out of work for a year, can't afford to have it done. The motor was 92.00,the start/run cap 16.00 x2 for compressor and fan, and the fan/hub was 65.00. So that is close to 200 bucks, don't want to burn that motor or compressor up. Oh, I forgot the contactor, that was 50 bucks. Don't want to throw all that money away. The old Goodman fan had been going out for a while, no cool air, then went out to watch it and it smoked. I hear they charge crazy money for compressors, and you have to have that done if you are not licensed... I haven't had air for 2 weeks, don't have all the parts yet...

I hear you. I am near Las Vegas and we hit triple digits all week. I am disabled so the wife and I are home all day. It's absolutely necessary to have it. I spent $ 40 on a contactor, $ 30 on a t-stat and $ 200 on the tech calls. The only thing I got out of the tech calls was a check on the compressor with the gauges. And a lot of mis information. It's obvious these guys don't think standing up. Anyway, anything else pop up, I've fixed all my own equipment, tools and cars when I worked as a stair builder for 35 years. I've done every bit of my own plumbing, electrical, paint, etc here so I may not be right, but I will have an idea. Don't hesitate to contact me if you want to bounce it around.