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here's a word that is used often and misused even more often. 

28 years ago we had a Managing Director of a large Steel Mill from Bangladesh drop into our office unannounced. 

We had offered him a 1500 HP Rolling Mill motor from ready stock and he dropped in to inspect it. 

Back then i was surprised that such a senior executive would fly down for an inspection like this. 

He saw the motor and signed on it in 3 places. Upon deeper probing he shared that earlier he was duped by unscrupulous businessmen who gave him a lower price and shipped him a used motor instead a new one. 

Fast-forward..... Last week a senior Procurement Executive from one of the largest Steel manufacturing groups of Telangana visited our Global warehouse. 

He was here to inspect the motors that his Mill needed urgently. 

Upon discussions, we learnt that he had ordered the exact same motors with a low-cost supplier who delayed the shipment by 8 months and then supplied them with repainted used motors. 

It's a shame that people cheat like this. It's a shame that people do anything for a quick buck. 

What's even sad is that buyers who choose to order based on price often face such situations repeatedly. 

In the last 54 years with customers across 45 countries, Team New India Electricals has been known for TRUST and Authenticity. 

TRUST is a given with us.  TRUST is non-negotiable. TRUST is our very foundation. 

Please visit our Global Motor Warehouse to see our stock and understand our commitment to our customers. 

Part 3

If your Steel factory has a capacity of fewer than 5 Million tons/year and is located near an Industrial hub then AC Motors with AC drives would be a good choice. 

However, if you are located away from an industrial hub in a remote location then i would recommend choosing DC Motors & DC drives. 

Here thinking of serviceability in event of a breakdown. Steel manufacturing is a continuous operation. Cannot afford long delays in serviceability. 

DC motors have been in use in Steel making actively for more than 40 years. Finding service engineers for them is easier. 

So if am staying in a remote town, I would prefer to buy a Maruti car over a new 5/6-year-old brand. My car can be serviced more easily & economically if it's a Maruti. 

Part - 2 

Here I am trying to explain the below sentence, it may be noted that I am an Electrical Engineer, 1992 batch so please take this with a pinch of salt, however, my attempt is to give you not only accurate knowledge but also lessons learned from practical experiences.

The one sentence I used in Part - 1 is, 'if you are setting up a large capacity unit higher than 5 Million Tons per Year (5 MT/Y), with a good quality power supply, located near an industrial hub go for AC Motor & controls, else go for DC Motors and DC Controls'. Now, am going to break up this sentence to explain each part for a deeper understanding.

If you are setting up a large capacity unit higher than 5 Million Tons per Year (5MT/Y) go for AC motors, but if you are setting up a smaller unit, i.e. less than 5 Million Tons per Year (5MT/Y), then I would recommend the use of DC Motors because these are lower in cost compared to AC Motors for the same performance with a slight trade off on speed variation.

Also, a smaller unit means, a lower budget and lower capacity, and thus you need to stretch your resources to the maximum.

DC Motors are one of the most robust, hardy, and reliable workhorses in the STEEL industry. 

Some Gyaan - any electrical device is limited by its 'COOLABILITY', ie how well it can maintain its temperature within operating limits, which is a key aspect of its design and performance.

Every electrical equipment's design has to factor in this COOLABILITY aspect, like in Transformers - the oil helps perform this function, in a typical Motor the fins help do this, in a circuit breaker the air around it helps this, in a conductor the jell or air helps address this critical need and in a computer the cooling fan/heat sink, perform the same task.  

A Typical DC motor used in Steel Mill application has 2 forms of cooling. The first is its Laminated Yoke design and the second is through the Force Cooling unit (IC-06). A Typical AC motor used for the same application has Cooling through the Cooling fan fitted on the Non-Drive End (NDE) and the fins on its stator body.

The Yoke in a DC motor is for providing stability and a providing a return path for the eddy currents that waste power and heat the metal frame of the motor. Using a laminated yoke in a DC motor reduces the losses of power and also reduces heating, allowing more power to be drawn from the motor and allowing the motor to run with less energy waste. 

I can go on talking about many other technical and electrical aspects but am restricting myself to a generalized knowledge transfer here, with the hope of easier ingestion, simplicity and decision making.

PART -1

One of the oldest and most pertinent questions that Mill owners and Engineers ask me is, should we choose AC motors or DC Motors to run our plant ?

The answer is different for different applications, and different installations in different conditions.

Typical Possibilities:

New plant - Small

2. New Plant - Large

3. Integrated Steel Plant

4. Old plant upgrade

5. New Plant remote location

6. Technical strategies are different for different types as above.

Another set of criteria can be:

Cost of Power

2. Quality of Power Supply

3. Availability of Skilled Labour

4. Availability of Capex and so on...

Each of the above calls for a deeper study.

Over the last 50 years, we have been one of the largest suppliers of Motors to the Steel Sector across 45 countries. This experience has given me a rather rich insight into this industry and its many challenges.

In one sentence, if you are setting up a large capacity STEEL unit higher than 5 Million Tons Per Year (5 MT/Y), with a good quality power supply, located near an industrial hub then go for AC Motor & AC controls, else choose DC Motors and DC Controls. Over the next few weeks I shall try to explain myself in more detail.