Electrical Magnet Coil

Check the amperage draw, you may have a shorted coil....

the coil is ok that it energized and attached the contactor and close it.

220vdc into 1ohm is nearly 49kW. Are we really surprised by this coil getting warm, Mildred?

the coil is ok,do you know how i can reduce this current and keep the magnetic force at the same time???

Nothing with 1 ohm resistance takes 220 volts dc! Either it should not be energized with 220 volts dc or it should not be 1 ohm resistance, period!

If that coil was okay before, it's toast now. Replace it and the card.

The time to discuss this matter directly with the original equipment manufacturer is long overdue.

Yes. Talk the problem through with ABB's technical advisers over the telephone.

i tried to energize the coil from 220v dc source

And it got hot? Is the coil control voltage the card is supposed to produce actually 220V dc or something else? If so then the coil resistance is too low, and I suspect a faulty coil.

Check the ABB datasheets and find out what your installed coil resistance is supposed to be, if it doesn't match replace the faulty coil.

the card output when i measured working card its output was 200v dc and also when i measured ac output it give 112v ac i check with oscilloscope i found a strange wave i think it is ribble so i energize the coil with 220 v dc and the cont actor already work i need way to reduce the sealing current of the coil and way to decrease the back emf when d energize the coil.the resistance off coil i dont remember if it was 0.6 ohm or 6 ohm.

Even if it was 6 ohms, that means your coil was trying to draw 220²/6 = 8067 watts. Come on mate, use your head. NO contactor coil is designed to dissipate 8 kW.

I have doubts that either the coil is faulty or you are using the wrong supply voltage. Have a look in the manual and on the equipment and see if you can find a part number and voltage. If you put the wrong voltage on the coil it is probably damaged and needs to be replaced like the driver card.

When you measured that 200VDC: was it under load or were you measuring it with a high impedance meter?

Maybe there is a large series resistor on the board.

Is an economy resister fitted in line with the coil?

If the resistor has short circuited then the coil will have the full voltage while in the closed position.

resistors don't "short", they fail open

carbon resistors CAN go down in value! That's only one reason they are not used much anymore.

Replace the current equalizing card; it's job is to limit the inrush current until the movable armature is sealed in, then reduce it even further since the holding current is much lower than the inrush. Failure to do so will result in a burnt coil and/or fire.

Usually for D.C. Contractors, there will be Economic resistor in series with the coil, and it will be shorted with auxiliary nc contact of the contactor, so that during pickup the coil will get full voltage and after pick up the resistor will be in the circuit to maintain the contactor in on position. After pickup the nc to become open

Check this circuit.

Nc means normally closed

Have some good read: Insulation Testing

https://www.instrumart.com/assets/Megger-insulationtester.pdf

http://www.fluke.com/fluke/caen/community/fluke-news-plus/articlecategories/hvac-iaq-news/choosing-insulation-resistance-testers

http://www.sprecherschuh.com/library/techdocs/posts/2014/01/ca7-coil-resistance.html

You have phoned someone at ABB about this, haven't you?

Funny, it worked yesterday.

dear sirs,

thanks for replying ,may be i couldn't describe what i need,

the equalizer card is damaged and it is very expensive so i need another inexpensive way to energize the coil and in the same time dont damage it ,my friend already rewind another contactor coil in another substation that it work in 110v dc and it already work for more than year now ,but i search for method to energize the original coil without rewind it ., i already agree that 220v dc supply isn't the solution ,but i need suggestions to energize the coil with inexpensive trusted method,i may use resistor with nc contact of cont actor but it need try and error ,also instead of resistor i may use high resistance coil.

thanks..

Your electric utility cannot afford replace that card and a new contactor coil??? Surely not! That doesn't sound very promising in the long run. How much does a power-outage cost in comparison to the cost of a proper repair? Cobbling things together with bubblegum and baling wire and your system is living on borrowed time. Trial and error? You tried it once and it resulted in error - you fried your contactor coil and very likely scorched the insulation.

If you're going to rewind it (I'm guessing you have no choice, given that your utility company seems to be flat broke) find a contactor with similar specs whose coil operates on the voltage you wish to use and wind it according to that. We cannot see your contactor from here and so we can only guess as to what its specs are, plus that coil was designed to be used with that card, not in the manner you're proposing.

A coil designed for ~110-220 vdc contactor service will typically have a resistance in the 100s of ohms and in the ballpark of 10 watts' power dissipation or less. NOT ohms and kilowatts.

What is ABB's part number? How big a contactor are we looking at?

Don't, the risk is too great. Contact ABB for a proper solution which may just mean replacing the coil with a different type. The card is there for a reason. Heck, look online and buy one second hand.

my friend already rewind another contactor coil in another substation

This suggests your application is an 11kV network SUBSTATION!!! See above warning, I don't care what country you are in and what you believe is common industry practice this is a serious application, GET THE PROPER REPLACEMENT GEAR OR YOU WILL REGRET IT!

Exactly!

The card may have been damaged by a contactor coil failure, 6 ohms is too small except for a 25 volt dc rated coil with an economize resistor, or maybe an ac coil, still less than 100 volts ac.

As long as you have a circuit through the coil, the magnetic field may pull in the armature, but that doesn't make the coil good. It just has enough ampere turns to pull in the contactor, the amperes are just unsustainable.

The rewind is likely your only option, other than repairing the card and likely repairing the coil.

<...it is very expensive...> So, what is the cost of not doing it? Why bother to carry out a repair? Why not just lock the door and throw the keys away (rhetorical questions - NNTR)?

That would be cheap!

How did the telephone calls with the manufacturer go?