Installation MV Capacitor

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hoantran0712 Member Join Date: Jun 2007 Posts: 9	Installation MV Capacitor 04/16/2015 12:03 AM
	Dear Friends, I have a question about installation MV Capacitor for my factory. The single line diagram is below. Our factory use both power source: From National Power (via 110kV Transformer) and Generators. We want to install a MV Capacitor bank to improve the cosphi (0,84 to 0,93, this is requirement of government) at point of busbar as noted in below picture. But I'm worry that it will be impact on the AVR of Generators (or the Excitation of Gen). PS: Generators could not fully supply reactive power for system Please help to advise me the best solution with lowest cost for this case? thanks
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RAMConsult Guru Join Date: May 2007 Location: NYC metropolitan area. Posts: 3230 Good Answers: 444	#1 Re: installation MV Capacitor 04/16/2015 12:23 AM
	The best solution at the lowest cost is to hire a consulting engineer to guide you, any other solution (including asking anonymous strangers on the web) will cost you time, money, and aggravation well beyond the consulting fee. If you have to ask then this is not a do it yourself project that you should undertake. __________________ “Tell me and I forget. Teach me and I remember. Involve me and I learn.” Ben Franklin.
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Crabtree Guru Join Date: Jul 2007 Location: Commissariat de Police, Nouvions, occupied France, 1942. Posts: 2599 Good Answers: 77	#2 In reply to #1 Re: installation MV Capacitor 04/16/2015 3:59 AM
	Bravo. __________________ Good moaning!
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jmueller Guru Join Date: Jul 2006 Location: Eastern Kansas USA Posts: 1503 Good Answers: 128	#3 Re: Installation MV Capacitor 04/17/2015 8:22 AM
	hoantran0712, Ram Consult's reply is valid and good advice. Although many members of this community have a lot of knowledge and experience in this topic, they would therefore be very reluctant to advise you unless they were to have seen the installation themselves. Since most problems with low power factor are caused by inductive loads (motors), has your plant considered the addition of capacitors at each of the main motor loads. If they are switched on when the motor starts/runs and switched off when it is off, they will give direct correction of the power factor. If the motors are on VFD's, then this approach is not possible. A problem with this approach has to do with how they are connected--in parallel with the motor after the over-current protection requires a re-sizing of this protection, and in parallel with the motor via a second contactor adds to the control components. --JMM
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Oomborrie Power-User Join Date: Jan 2015 Location: Johannesburg, South Africa Posts: 248 Good Answers: 3	#4 Re: Installation MV Capacitor 04/17/2015 5:32 PM
	If you understood how power factor correction worked you would not need to ask this question, I have to agree with RAMConsult that the complicity will at the end force you to get consultants with the right equipment to isolate and measure every Distribution board and suggest some automated switching PF correction system for each area that will be able to fix the change in inductance as the load and speed of motor change. Single pack Transformers is very seldom a solution in multi motor factories. __________________ Tragedy for Engineers is thinking they know so much that they can not learn from any body else.
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1capybara Power-User Join Date: Mar 2012 Location: the sandbox Posts: 341 Good Answers: 6	#5 Re: Installation MV Capacitor 04/18/2015 3:25 AM
	BTW I cant read your photo of a diagram even enlarging it 1000%, in the future please scan stuff in intead of photographing it. thank you Sir! __________________ BSEE but always learning
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Wal Guru Join Date: Jun 2011 Location: Phnom Penh Posts: 4019 Good Answers: 102	#6 In reply to #5 Re: Installation MV Capacitor 04/18/2015 3:47 AM
	Nothing wrong with photos of documents. I was in search of an A3 scanner once. Not cheap. My regular computer vendor suggested taking a photo...brilliant. My camera is my portable photocopier! Even scanning doesn't guarantee a legible image. I've used a scanner as a camera before and the results can be pretty good too. The best part about digital images is you can look at them before printing or transmitting them and take another one if required right away. I hate it when I receive technical images that don't show squat. I query whether the image was previewed at the time of it being taken to ensure it actually shows clearly what it was meant to show.......the person never thought of it. Seriously, what's the point of an image that doesn't meet its purpose. No excuse for crappy photos these days. Worse still is if the image subject is not easy to get to again.... __________________ Difficulty is not an obstacle it is merely an attribute.
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Oomborrie Power-User Join Date: Jan 2015 Location: Johannesburg, South Africa Posts: 248 Good Answers: 3	#7 In reply to #6 Re: Installation MV Capacitor 04/19/2015 8:43 AM
	just in defense to the original poster, he looked at that diagram so many times and so long that he knew it by hard and could decipher every little thing on that "little" diagram. __________________ Tragedy for Engineers is thinking they know so much that they can not learn from any body else.
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Wal Guru Join Date: Jun 2011 Location: Phnom Penh Posts: 4019 Good Answers: 102	#8 In reply to #7 Re: Installation MV Capacitor 04/19/2015 10:43 PM
	Unfortunately empathy doesn't transmit well as data. __________________ Difficulty is not an obstacle it is merely an attribute.
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These comments received enough positive votes to make them "good answers".

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1capybara (1); Crabtree (1); jmueller (1); Oomborrie (2); RAMConsult (1); Wal (2)

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