Square D Contactor... need urgent help!

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Rockyd

Senior Member
Location
Nevada
Occupation
Retired after 40 years as an electrician.
How inportant is this as a "must happen"?

In Alaska, we wave a $100 bill at the door of certain supply house, and the doors will open. Sometimes it can be more....
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
The stop button is a normally closed contact, when you push it, it opens breaking voltage to the coil, that is why they are in series, so if any one of them is pushed, the coil drops out, therefore also opening the holding contact on the side of the starter. When you say you push in the contactor on the starter,it works, so it stays in until you hit the stop button? Or does it drop right back out?
 
The stop button is a normally closed contact, when you push it, it opens breaking voltage to the coil, that is why they are in series, so if any one of them is pushed, the coil drops out, therefore also opening the holding contact on the side of the starter. When you say you push in the contactor on the starter,it works, so it stays in until you hit the stop button? Or does it drop right back out?

When I manually push the contactor, the motor starts, even if I hold it in for 30 seconds, there is no coil keeping it in. As soon as I release, it stops.

We're testing the coil ATM...

If the coil is bad, do we need to get a new contactor?

Greg
 

emahler

Senior Member
When I manually push the contactor, the motor starts, even if I hold it in for 30 seconds, there is no coil keeping it in. As soon as I release, it stops.

We're testing the coil ATM...

If the coil is bad, do we need to get a new contactor?

Greg

no, you can replace the coil, usually...what gives power to the coil? when you press the Start button on your push station, do you get the proper voltage at the coil?
 

emahler

Senior Member
It's 8pm, the lights are on, I'm warm best of all it's not my fault:grin:

Start with the basic. Do you have voltage to coil? Did you blow the coil?

i just got a phone call from a customer of mine...it's a theater with a show about to start...no follow spots...but, i was able to talk them through the issue without leaving my warm, well lit home...:D
 
The stop button is a normally closed contact, when you push it, it opens breaking voltage to the coil, that is why they are in series, so if any one of them is pushed, the coil drops out, therefore also opening the holding contact on the side of the starter. When you say you push in the contactor on the starter,it works, so it stays in until you hit the stop button? Or does it drop right back out?

You are right... the stop button is NC...

Thanks there... would have missed that and been looking for a while...

"Man, I can't shut it off!"
 

ceb58

Senior Member
Location
Raeford, NC
i just got a phone call from a customer of mine...it's a theater with a show about to start...no follow spots...but, i was able to talk them through the issue without leaving my warm, well lit home...:D

And you can invoice in the same climate:grin:
 

bjp_ne_elec

Senior Member
Location
Southern NH
Greg - did you test across the OLs? I can't remember if SquareD have a reset button - but some OLs do.

First off, do you have the correct (coil) voltage at the switch? There normally is a control fuse. What wire got hit with the screw?

Do you have a control book? If not, I can draw out the circuit. Do you have Power Point?
 
Greg - did you test across the OLs? I can't remember if SquareD have a reset button - but some OLs do.

First off, do you have the correct (coil) voltage at the switch? There normally is a control fuse. What wire got hit with the screw?

Do you have a control book? If not, I can draw out the circuit. Do you have Power Point?

Do have power point.
Which wire? Not sure atm. Can go check.

Do not have the control book.

This OL does have a reset button, but that is not solving the problem.
Pushing it in, or push & twist & keep in is not working...
 

emahler

Senior Member
Do have power point.
Which wire? Not sure atm. Can go check.

Do not have the control book.

This OL does have a reset button, but that is not solving the problem.
Pushing it in, or push & twist & keep in is not working...

when you manually push in the contactor, does the machine operate? yes? nothing to do with the OL...

what is your voltage at the coil while you press the start button?
 
Ok, electrician onsite just did something that tripped the breaker controlling all this... since the place is not open right now, we are at a stand still... the panels are all inside.

The place is a car wash... and they will be open for business tomorrow morning.

My electrician says that he was getting 280V on the coil before everything blew...

I verified he said 280, and not 208...

So, thanks for everything.

We'll be heading to Denver early morning tomorrow. They have one in stock, and we'll get that, so that the customer can have his system back up.

Greg
 

ceb58

Senior Member
Location
Raeford, NC
Greg, slow down dude. You are getting tunnel vision on this one. If you can push the contactor in by hand and the motor runs then that part is ok. You have an issue with the control coil that is not pulling in to start the motor. Several have ask including my self. What is the coil voltage?
 

emahler

Senior Member
So, the next question is: How do I handle this?

Obviously, the customer is not responsible for ANY of this... but what do I do to the employee?

suck it up and make sure to remind him every chance you get...nothing else you can do...labor laws are a bitch...
 

Cow

Senior Member
Location
Eastern Oregon
Occupation
Electrician
when you manually push in the contactor, does the machine operate? yes? nothing to do with the OL...

Do you specifically know this style of starter, the part # sounds similar to a Telemeqanique I bought a while back? Reason is, I know some overloads will still pass current even if the NC contacts are open due to an overload. Starting the motor by pushing the starter in manually doesn't necessarily mean the overloads aren't tripped.

what is your voltage at the coil while you press the start button?

This should be your first step, after checking for blown fuses and proper voltage at the starter. Do you have control voltage?
 
Again, the electrician tells me he reads 280V on the coils... I asked him to be sure.

I think he may have mis read something, but he tells me that is what he read. I asked to make sure it was not 208, and to make sure it was not 28V.

We no longer have power, so I can't tell.

Yep... I gots tunnel vision...
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
So, the next question is: How do I handle this?

Obviously, the customer is not responsible for ANY of this... but what do I do to the employee?

Take your lumps and go on, berating the employee will usually get you nothing but ill will. At least you are learning the limitations of the employee in question. If they are otherwise a good employee, consider having them take some courses to improve their skills. If you are doing a large amount of control work, an industrial controls night class would be the ticket. Many community colleges and tech schools offer these courses.
 
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