1/2hp controller on 1/3hp pump?

[therabidweasel]

I have a 1/3hp 3-wire submersible pump/controller from franklin. Was watering the lawn this weekend when I lost pressure. The coil resistance measured across the relay is a dead short and I therefore think it is the controller. Since it is sunday I cant find the exact parts I need so I thought I could go to lowes and buy a different brand controller. All they have is 1/2 hp controllers which has a 59mfd start cap instead of 43.5mfd. The relay coil appears to have an OK (5.4k) resistance. I was wondering if the extra capacitance could take the motor far enough out of phase to screw it up. Anyone know/done this?

 

[therabidweasel]

The new controller does not appear to have an overload protector in it like the franklin I am trying to replace. Since that appears to be the only thing saving the pump right now I dont think I'm going to install it. . .although I am tempted. I'm getting pretty gamey after 2+ days without a shower.

Bob NH, I live in Bedford (Bedchester/Manford actually). Know any good well guys locally? Maybe you arent supposed to say on here. Anyway, I dont know anyone within 1700 miles of here so I'd appreciate any advice.

 

[Sponsor]

 

[Rancher]

Be Prepared

My franklin controlers don't have overload protection... but they do have the same size caps as you are quoting, one is a franklin re-branded and sold by Sears, have you given them a call? Or just try buying one of those 1/2 hp controllers and swaping out the start relay.

Maybe it's the Boy Scout in me, but I always keep an "extra" of everything except the pressure tank on hand.

Hope you get a shower soon... or try Motel Six

Rancher

 

[therabidweasel]

Being prepared is definitely the best option. . .not a normal thing for a house you've only been in for 2 months though. I will buy an extra controller when replace this pump though. Good idea.

I guess I'll let the dog give me a bath tonight. . .

 

[Raucina]

Obviously you have some test equipment - Did you check the resistance in the 3 drop wires to spec's for your motor? If your pump box has a reset switch and it is tripping, the motor is suspect more than the controller, so make sure its okay before proceeding. Assuming the motor checks out, I would get it started [to temporarily get water] with the 1/2 hp box and check the amp draw.

 

[therabidweasel]

Thanks Raucina,

I checked the motor, the main is 8.1 and the start is 8.7. Resistance to ground is 500k on each leg. . .which is low by what the box says but I have a very cheap meter. . .I'll be getting a fluke (again) because of this.

I cant find what the windings are supposed to be. This is a 1/3hp franklin pump and it is not in the AIM manual.

I did hook up the 1/2hp controller and it pumped probably a gallon of water, enough to register the bladder pressure on my tank and then it quit. I believe I must've blown the cap on it too. Taking off work this morning to get a new franklin controller. . .crossing fingers it is not the pump.

BTW, I think it was tripping the overload because the cap wasn't there to start the motor, which maxed the draw out. I dont have a clamp so I'm not measuring the current, I am just assuming because I heard the relay trying to start the motor. It was kicking in and out every 2-3 seconds. . .of course the armature could be locked, but it did pump some for me last night. How does that sound?

 

[Speedbump]

If it's not too late, the cap being bad would definately keep the motor from starting. If the relay's coil is bad, the start cap would be the next thing to go. If the relay can't de-energize the cap after the motor has started the cap will blow in seconds.

The difference in the start caps is nowhere near enough to be concerned about. They will both work. Your readings to the motor are where they should be. But the 500K to ground is not a good thing. This indicates the motor the wire or both are going to ground. It may still run, but probably not for long.

bob...

 

[therabidweasel]

If it's not too late, the cap being bad would definately keep the motor from starting. If the relay's coil is bad, the start cap would be the next thing to go. If the relay can't de-energize the cap after the motor has started the cap will blow in seconds.

The difference in the start caps is nowhere near enough to be concerned about. They will both work. Your readings to the motor are where they should be. But the 500K to ground is not a good thing. This indicates the motor the wire or both are going to ground. It may still run, but probably not for long.

bob...

Roger on the cap and relay. As for start caps, I'm not sure, I may run a simulation sometime. . .I dont usually deal with 60hz (or anywhere near that). I millifarad is a lot, 16 of them is fairly massive. Bob NH, my new best friend, sent me a couple of extremely valuable links:

http://www.goulds.com/product.asp?ID=95&MASTERID=3

http://www.goulds.com/pdf/TDSINGLE.pdf

From these, it looks like my start winding is 1/3 the value it should be. 500k to ground is what I am supposed to be measuring with a pump in the water, so I think I'm alright there. Looks like I am hosed and in for more dirty unpleasantries. . .which is how my wife describes our honeymoon. I digress. . .

 

[Speedbump]

Don't forget, your also measuring all the wire leading to the motor, so your reading is going to be a bit high.

The 500K ohms on the wires to ground is where Franklin says to pull motor and inspect/replace if it's not just the wires that are grounded. So if your seeing 500k or less to ground, your motor or it's wires are on the way out.

bob...

 

[Raucina]

Sounds like the motor is pulling high amps and you will be pulling it out. Wouldnt waste time and money on any on more control boxes right now.

 

[vaplumber]

If the mfd rating is higher (but not more than double) it will work. Make sure your wiring is the same, and that your relay resistance is the same. If youre blowing them out like this, pull the pump, be smart, throw away the control box and drop a 2 wire pump back in its place. Fewer problems. Longer life. No caps or relays, and the motor will out last the pump head.