well pump control box

HAWKMAN · 08-04-2009, 12:05 AM

I have a deep well with a submersible pump. It is 3wire, 230 volt. The casing is 6 inch steel. The outlet is 1.5 inch PVC located 4 feet underground. Someone took the motor control box. I do not have access to pump or motor info. I need to get the pump operational fast as it is a contingency on closing the purchase of the land and ordering a house. The previous owner gave me what he thought was the old control box. It was rated 3/4 horsepower. The capacitor blew. The pump was running about 16 amps for 1 to 2 minutes before it blew. I checked resistance of the motor windings to see if it shorted. Seems to be ok. All three wires to ground are open. Common to start is 9 ohms, common to run is 3.0 ohms, start to run is 10.8 ohms measured with a fluke fieldpiece. Can anyone tell me what the horse power is and if a run capacitor is required, or just a start capacitor and relay.

chris75 · 08-04-2009, 09:42 AM

Quote:

Originally Posted by HAWKMAN

I have a deep well with a submersible pump. It is 3wire, 230 volt. The casing is 6 inch steel. The outlet is 1.5 inch PVC located 4 feet underground. Someone took the motor control box. I do not have access to pump or motor info. I need to get the pump operational fast as it is a contingency on closing the purchase of the land and ordering a house. The previous owner gave me what he thought was the old control box. It was rated 3/4 horsepower. The capacitor blew. The pump was running about 16 amps for 1 to 2 minutes before it blew. I checked resistance of the motor windings to see if it shorted. Seems to be ok. All three wires to ground are open. Common to start is 9 ohms, common to run is 3.0 ohms, start to run is 10.8 ohms measured with a fluke fieldpiece. Can anyone tell me what the horse power is and if a run capacitor is required, or just a start capacitor and relay.

Umm, match up the control box and just go buy another one. Why the hell would someone take it anyway? But just for your info, a 3/4 HP motor at 240volts will draw 6.9 amps, and here is the winding resistance for a 3/4 HP motor also, Main Winding (yellow to black) 3.0-3.6 Start Winding (yellow to red) 11.0-13.4

But without knowing what pump is actually in the ground, you really have no choice put to pull the pump, buy the correct size control box, or pray the one the last owner gave you WAS the correct one, and just go purchase another.

williswires · 08-04-2009, 10:41 PM

In my area, the well driller stamps the well cap with the depth of the well and the HP of the pump. Maybe you have that sitting around if it's not on the cap.

chris75 · 08-05-2009, 10:29 AM

Quote:

Originally Posted by williswires

In my area, the well driller stamps the well cap with the depth of the well and the HP of the pump. Maybe you have that sitting around if it's not on the cap.

Thats not a bad idea, around here they mark the depth on the control box.... LOL...

md2lgyk · 08-06-2009, 10:42 AM

What is the "motor control box" for? My well pump doesn't have one.

micromind · 08-06-2009, 11:46 AM

Single phase submersible pump motors come in two types; 2 wire and 3 wire.

The 2 wire type doesn't need a control box. Just energize the two wires and it runs.

The 3 wire type has both the start and run winding wires brought out. The control box is needed to de-energize the start capacitor after the motor is up to speed.

Rob

HAWKMAN · 08-10-2009, 12:37 PM

Thanks for all the info guys. With this and a conversation with Culver motor and armature in Sacramento, I am relatively sure I have a 3/4 hp pump. It will be 2 to 4 weeks before I can get back to Idaho to test it again.
HAWKMAN