Another Electrical Question

[Catdaddy]

As ya'll mentioned before, I found that fire ants had shorted out my contactor. It looked fried so I bought another one along with another overload relay.

It started and ran for a while but I'm pretty sure the overload kicked in.

From looking at the pictures below, how would I reset the overload once it's kicked out? I'm also going to adjust the overload to around 50 amps.

This is the old unit, but it's identical to the new one.

[SCSportsman]

What hp is the pump motor?

[Catdaddy]

10 hp

[SCSportsman]

At 240V (3-phase), you are looking at running load current of 28A. I would expect the overload would be set around 45A.

[Catdaddy]

It's wired single phase and the relay was set at 46 amps. The new relay is tripping at 46 amps.


The white button in the middle is a trip indicator and the blue button is the reset. My question is....how do I reset it?

[Quack07]

Should be able to push the little white button inside the blue block. You may have to wait a little bit after it trips and hit the button for it to reset. Assuming they are thermal overloads, they will have to cool down before you can reset them.

[SCSportsman]

Single phase puts you at 50A (running load)

[Catdaddy]

Single phase puts you at 50A (running load)

So I should have it set at 50 amps?

[SCSportsman]

Probably closer to 75A

[FLS]

The white button inside the blue button, that looks like a phillips head screw, should have two settings manual and auto. Rotate it to manual. Push to reset. If it clicks it was tripped.

If the overload relay is solid state with phase loss protection you will have to run a jumper through whatever phase you are not using. Since it ran for a while, I doubt that is the case.


OL relay needs to be set at 60A (FLA + 20%). If it continues to trip after setting to correct trip point, you need to check the amps while it is under a load.

[SCSportsman]

The white button inside the blue button, that looks like a phillips head screw, should have two settings manual and auto. Rotate it to manual. Push to reset. If it clicks it was tripped.

If the overload relay is solid state with phase loss protection you will have to run a jumper through whatever phase you are not using. Since it ran for a while, I doubt that is the case.


OL relay needs to be set at 60A (FLA + 20%). If it continues to trip after setting to correct trip point, you need to check the amps while it is under a load.

Actually, what he said. Not sure why I put 75A, shouldn't type and talk on the phone at the same time. For a 1.15 service factor motor it would be 1.25 x RLA or 62.5A.

[Catdaddy]

Actually, what he said. Not sure why I put 75A, shouldn't type and talk on the phone at the same time. For a 1.15 service factor motor it would be 1.25 x RLA or 62.5A.

This relay adjusts up to 63 amps.


Thanks guys.

[Catdaddy]

I give up. Couldn't get it to reset. I've wasted 5 days on this mess.

Looks like I'll just start hunting in Arkansas after Christmas.


Here's what it looked like for 30 minutes.

[FLS]

Give the relay some time. If it's bimetallic it will take a while to cool off and reset. When it does disconnect motor leads from the bottom of the OL relay and turn it on. If it closes and stays closed your motor is the problem. FWIW single phase motors suck. Internal switches and capacitors are good for my business though.
You might want to look at using a Variable Frequency Drive to go from single to three phase, allowing you to use a 3 phase motor which will cost about half what single phase will. The initial cost of the drive will be recouped through increased motor longevity and decreased repair costs. They have gotten significantly less expensive and more user friendly in the past 10 years. You can also fine tune the motor speed to prevent cavitation and impeller wear.

[FBT]

Do you mean a phase converter or are you saying get three phase power from a VFD?

[FLS]

Not a phase converter, a VFD. Yes single phase in, three phase out. Supply has to be 220v and it approximately doubles the size of the drive(amps). 10 hp motor would take a 20 hp drive. You have to disable the incoming phase loss protection.
Google drive applications.