It’s Sunday again. We have planned to post an informative blog on Sundays. So here we are.
Now a days, almost in every industry, we find some typical problems like burning of cables even though they were of correct rating or burning of VFDs or burning of SMPS units. We check all the ratings and actual load and find them correct. Then why does this happen?
We shall solve this mystery soon.
In these days, all the machinery are coming with drives. Those may be AC drive or DC drive. But both these drives need to convert the 50Hz AC power into DC power first. So these units use rectifier circuit. Rectifier circuits actually cut the AC wave and convert it into DC. During this cutting, the AC waveform gets distorted. This distortion is nothing but the induction of harmonics in the pure sine waveform of the current or voltage. These types of loads are called as non-linear loads. And these loads lead to harmonic distortion.
Once these harmonics are induced, they start flowing throughout the system. All the systems are designed normally to work at 50Hz or 60Hz. Now suppose a current of 16A flows through a conductor of 20A rating. This is normal condition and the conductor will not heat with current. Now suppose due to non-linear load, a 13th harmonic current of 300mA gets induced in this system. You will be able to detect this current on your tong tester or multi-meter. But this current will produce heat equivalent of 17A in the cable. It will be like the cable is carrying double the current than its rated current. And this will surely lead to burning of cables. Now do you realize that how horrible this monster is?
So what’s plan to kill this monster?
Step 1. Find out where is it coming from? Get the harmonic analysis done by professionals.
Step 2. Get the solution to reduce harmonic level from professionals.
Step 3. Apply the solution.
Step 4. Keep doing these steps from 1 to 4 after some specific period such as 6 months or 1 year.
We, at SYCON provide all these services. If you need more information on this, please contact to our official mail id or connect to us on phone.
What we just discussed is just one effect of harmonics in the industry. There are many like this and we shall discuss them one by one in this Sunday series.
Good Luck !!