How to Size Transformer Capacity and Over Current Protection Device (OCPD) | Engr. Noel
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- เผยแพร่เมื่อ 7 ก.ย. 2024
- Good day mga Boss. In this video pag usapan natin kug pano ba tayo mag size ng capacity at circuit breaker ng transformer. Sana makatulong sa inyo.
Thank you for watching!
Don't forget to like, comment and subscribe. God Bless
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Thanks engr. sa topic mo
thank you sir noel!! the best info out here in youtube.
Thank you🙂🙂
Thanks sir additional info
Good Day Sir. Maraming salamt po sa video. Request ko lang din po sana, generator sizing, capacitor bank sizing at yung mga protective device nila, saka busbar sizing at kung kailan gagamit ng busbar. Salamt po
Cge boss noted po..hehehe..dami ah
Yes sir maganda to sir
@@NoelLaude maraming salamat sir. Maganda po kasi mga turo niyo. Next topic din po sir parrallel transformer design at ano po gamit ng bus coupler. Salamat po ulit ng marami Sir hehehe.
Boss pwede ka mag discuss about fault calculation
Maraming salamat sir bossing marami akung natutunan sa inyu po.
Salamat din po. Masaya po ako at nakakatulong sa inyo
Thank you for sharing sir, dami ko natutunan. God bless you and to your YT Channel
Thank you din Boss
Salamat po addition sa knowledge po
Sir, pwede po magrequest? Time Current Curve po para sa relay coordination. Salamat po in advance.
sir sa schedule ng load .. san po nyo binase yung demand factor per ckt? yung 0.75, 0.98, 1.0, 0.94 ... ano po ba basis neto para iassign per ckt ?
Magandang araw/ gabi sayo sir...dati din po ako sa saudi ngayon lokal na ako nagtatrabaho bilang maintenance...may tanong lang sana ako sir...sana ma bigyan nyo po nang linaw...ilang kilowatts na load ba ang kaya nang 3 single phase 75 kva each transformer na naka bank ng wye- delta...at kung pwede sir..paano i compute o ano yung formula....sana inyong mapansin ...para maliwanagan ang isip ko.haha...ingat sir GOD BLESS..
Salamat po Sir
Quality CONTENT! keep it up Engr!
Sir kaka subscribed ko lang po dito thanks po sa mga videos nyo ask ko lng din po if mabasa nyo to computation lng po ng transformer losses natin. thank you
Cge boss try natin gawa yn.. salamat and God bless
ayos na ayos boss
Salamat boss
Salamat po sa video mo. Ano po ang upside at downside ng paggamit ng dry type transformer single to three phase?
@ 26:10, Code provides that CB or Fuse Rating is at 125% of "Transformer Rated Current" , if the Tx you had selected is rated at 2MVA, then its Rated Current is = 2000KVA/1.732/0.4kV = 2886.8A . Why then did you use the demand load 1867.1KVA (2695A) A as basis for Secondary CB rating , are you applying other rules when it specifically states "Rated Current as basis?
Tx Secondary Conductors are sized base on TX current rating , not bassed on load rating because the Tx sec. conductor ampacity cannot be less than the OCPD sized under 4.50.1.3B considering the 800A rule for Conductor protection.
an exeption to this may be small dry type transformer with specific load installed, but for a main distribution Tx, Rated Current should be the basis ie. 1.25 * 2887A = 3608.8A and not the maximum demand load, which the ACB can anyway be set to trip at 2695A or less.
regards
Sir Noel gud pm, bka may computation kayo ng short circuit for kaic pa share nman di ksi ako sure ng calculation ko. Tnx in advance
sir sana pinakita mo din yung table ng circuit breaker
Usually boss available yn sa mga manufacturer. Depende n lng Kung anong brand ung approved ng client. As long na alam mo size ng ocpd madali ng mag select.
Newly subsciber sir , Tanong ko lng po pano po isolve yung total load po ng isang facility kung nka3 phase po sya tsaka pano rin po malalaman kung anong size ng generator ang ilalagay dun , di po ba nka KW po pag sinolve yung total load eh nka KVa nman po yung generator po???
Kung wla syang as built drawing need m talagang isaisahin lahat Ng connected loads. Tapos gawan m Ng load schedule. As per naman s generator. Identify mo Kung anoanong load Ang susuplyan Ng generator mo. Depende din yn sa type Ng facility. Pero normally ilaw, outlet, communication at fire alarm system. Kung may BMS at access control minsan sinasama din yn Kung meron ung facility nyo. Kung kw ung loads divide m lng s power factor para maconvert s kva.
@@NoelLaude Thank you poo sir
sir idol..sample computation ka ng panel board loaded with accu outdoor unit?
Good day po,,,paano po ba i-compute total wattage Ng stepdown transformer na gagamitin?
Bale po kasi may dalawang Aircon dito na 120V, 1800 watts at 1560 watts.Balak ko sa Isang stepdown transformer lang sila Nakasaksak.
Ilang watts po ba Ng stepdown transformer Ang dapat Kong bilhin? Salamat po,Sana po masagot
Gud day engr. If the source of 240volts is 10 kva syncronous single phase alternator drive by 24hp diesel engine and my total load is 17kw. What type of transformer to buy???
Tama ba Sir pg , Single phase . Yun Maximum LOAd ng (Pole-mounted transformer ) = (KVA)(1000)/V
Good day sir. Meron din po bang Maximum Load (MDL) ng Transformer na nasa PEC katulad nang nabanggit mo sa 9:42? Kung meron, anong specific Article and section. Salamat
Gud day Sir Noel! Ask ko po kung anung way pra mlaman ang capacity ng trasformer kung wala ng plate n nklagay s transformer?
Good day sir.. as per my experience ibaiba Ang frame at orientation Ng terminals Ng transformer depende s manufacturer Kaya mahirap malaman ung rating Ng transformer Kung wlang nameplate. I suggest n s as-built drawings n lng ( SLD or plan layout). Kung may operation and maintenance manual kayo pwede din dun.
Sir. Can you do design a three phase explaining everything while doing the design mejo struggle ako because i am newly registered electrical engineer. I love your content sir hope you notice my request.
Good day po sir. Meron po akong video Ng 3phase design. Check nyo Po s videos ko ung Lighting loads, motor loads calculation
how about dry type power transformer what percentage of total rating to be use? TIA
Up to 90% Ng rating Ng transformer.
Hi sir noel! May I just ask, what do you usually use in design for basis of equipment rating capacity? Is it the total connected load (cl)? Or the max demand load? Is it not the CL? as you risk the transformer being overloaded because it was designed on the assumption that it won't exceed the max demand load.
Thank you
We size our transformer on max demand loads, normally up to 80% only of xformer rating. Also, I mentioned on the video, that we consider the diversity factor. Meaning all connected loads are not running simultaneously.
As long as we follow the correct sizing of ocpd and breaker settings, overload will not be an issue.
Sir ilang meters po ba kaya ng isang singe phase transformer?
Need po talaga Sir na malaki working space para sa maintenence,
Oo tama.. kc tyong mga electrical nahihirapan.
Sir noel last question po, bakit di po yung mismong rating ng transformer ang ginamit sa computation, bakit di po yung 2500 kva na transformer?
Nabanggit ko yn sa bandang dulo Ng video. May ibang Engr n ganyan ang practice pero Wla akong reference standard n nabasa n ganun dapat ang gagawin. Pero jn sa sample n ginamit ko.. the same size p rin ng ocpd gagamitin mo Kung calculated loads ang basis mo.
Sa pagsize kc ng transformer, as much as possible ung need lng ng building.. d pwede din ung malaki allowance mo kc medyo Mahal ung transformer
Maraming salamat engr. Noel
Sir, ung 600% po ba is para na yan sa inrush current ng transformer pag mag energize?
Yes boss, para sa inrush current sya.
Good pm anu ang malaking wire sa transpormer primary or secondary pareho lng ba stepdouwn or step up.
Magiging magkaiba size Ng cable mo s primary at secondary kc magkaiba voltage nila. Mas malaki cable s mababang voltage
Saang table makikita ang diversity factor?
boss pashout out naman po...want ko rin po na malaman kung yun pong submersible pump na 5hp ay kya ang transformer na 10kb yung control nya po may setup na line 1 line 2 ang circuit breaker po 60 amperes bigla po me pumutok sa breker nung bigla ko po itinaas ang breker para mabuhay ang makina...umandar lang po nang konti ung pump tas namatay napo ano po kaya problema nun...? di kaya po naapektuhan ang pump?
sir sa secondary ocpd nakasaad sa nec na up to 125% of transformer rated current..bakit yung maximum demand kva ang gamit sa pag size?
I think nabanggit ko n may ibang designers n ganyan ang practice, automatic 125% ng rated current ng transformer ang ginawa s pag size ng ocpd. Wla nman problem dun.. kc pag nagcompute k ng loadsyan p rin ang basis m s pag size ng ocpd
Every project ibaiba condition/situations minsan Hindi pa identify ung total loads. Kaya ung iba, kinoconsider n ung max size ng ocpd
okay po sir..salamat po sa pagsagot ng tanong ko..
Sir, di ko lang gets dun sa Primary OCPD niyo. Nakalagay ay for transformer with secondary voltage greater than 600 volts. Hindi ba ang secondary voltage niyo dun at 400 volts? and and Primary voltage ay 13.8 KV?
Yes po, ung 13.8kV ung primary and 400V ung secondary
@@NoelLaude Then kung 400 volts secondary, di siya applicable sa provision na transformer with secondary voltage greater than 600 volts. Hindi po ba?
boss bakit ACB ang nasa secondary protection mo at VCB ang nasa Primary protection? pwede ba ako gumamit ng MCB para sa secondary?
hindi ba rating ng transformer ang gagamitin or load calculation sirbakit hindi 2500kva sir
Hi Engr. Ano reference mo for Demand factor how you compute DF .79, .98, .94 or Meron ba Tayo table for demand factor.
Good day boss. Ung DF n .79, .98,,. Nakuha yn sa Calculated df Ng mga panels n connected s MDB TR1.
About s DF table, maron article na nabanggit sa pec Kung anong DF Ang gagamitin natin, for lighting, outlets.
Sir ok lang po ba gumamit ng tie breaker instead of RMU, since switching operation lang din naman para sa two sources yung role nya. Muka kasing secondary selective arrangement lang din yung nasa sample nyo sir
Pwede naman depende sa design mo at s type Ng building. Dto samin Ang main MV switchgear namin may tie breaker, meron din kming mga building n may MV switchgear merong tie breaker. Pero karamihan gamit nmin rmu lng Lalo n Kung d nman essential ung buildings. Para continues p rin ung mv ring network namin.
Sir Noel, paano po cable sizing ng transformer? Salamat po
Sa primary atleast 125%. Sa secondary depends sa type ng MDB mo.
Hello sir pls give us lecture in english language.
Engr. Usually ba RMU ginagamit if you have two power source? Sa Saudi ba dalawa ba lagi power sources nila? unlike sa atin na ung generator ung back up.
Yes boss common dto two power sources. Bukod dun may genset din s facility. Depends s type Ng building, minsan whole capacity, minsan fire fighting and security lng ung may genset.
@@NoelLaude salamat engr. Pashare nmn po ng NEC at PEC nyong gamit. Sa email ko po
engr.armelovargas@yahoo.com
@@NoelLaude engr. Pashare nmn po ng NEC at PEC. Maraming salamat po
Sir ano po yung Ring Main Unit sa electrical system?
switching device boss, pero ginagamit ntin sya electrical distribution, loop system particularly sa MV network. Bale two source ung supply natin. Incase magkaroon ng power failure ung isang source, may isa p tyong supply n mag distribute faciity natin.
Sir 13.8kv ung primary natin pero san po nyo nakuha ung 17.5 kv sir?
ur transformer capacity is 2,500 kVA, why not it's rating in the selection of OCPD ? Besides, in the calculation of kAIC rating of equipment the rated FLA or based current Ib of transformer is used.
Yes Boss, I think I've mentioned that in this video, that there are some designers that follows that method.
Sir ano po yong RMU?
Switching equipment sya, particularly ginagamit sya sa medium voltage power supply loop network na may 2 independent power source. In case mawlan Ng supply ung feeder 1, magoopen circuit sya then ung feeder 2 naman magsupply sa network
Sir pano naman pag generator