Thank you, this is a good one. A lot of tutorials forgot to include consideration of MCB trip curve characteristic in their calculation. In practice I prefer to be a bit more detailed with the trip curve calculation, but for learning this is good enough.
Nicely explained madam...these concepts are very useful to me ...why bcz i started electrical panel board manufacturing company ...so i request u to share ur full knowledge to me madam...tq....
Dear Madam, You have selected MCB 26A, OLR around 16A...that's fine... But you said in DOL, motor always draws higher current at start, (130A according to video). So that point is that how motor will continue to run even starting current is higher than MCB, OLR rating? There will be no tripping? Why? Because at start current will be higher than OLR, as well as MCB rating... Please clear this point, thanks
In short! Motor ka starting current initially high hota kuch mili seconds k liye(nearly 2 3 cycles me). Uske baad motor apni steady condition me a jaati h. Us initial time me high current bear krne k liye hi hum c Type mcb lete hain. For further detail Ap ek baar b,c and d curve MCB k characteristics study ke lo.
Understand that this is an old question, but commenting anyway in case somebody else needs this info. In general application, there are 2 types of overcurrent detection: Thermal, and magnetic. Thermal tripping uses a bimetalic strip that, during current overload, heats up and bends. The bending triggers the trip mechanism. The heating process takes time, and this introduces a time delay into the tripping action. The higher the overload current, the shorter the tripping time, which is why this is sometimes called a "inverse time" type circuit breaker. Magnetic tripping depends on the magnetic field strength generated by the current flowing through the circuit breaker. During overload the magnetic field is much stronger than usual, and this immediately triggers the trip mechanism. There is no time delay because change in magnetic field is immediate. This is also sometimes called "instantanous tripping". Overload Relay (low to medium spec models) exclusively uses thermal tripping system. This is why, in certain countries like mine, overload relays are more commonly called Thermal Relay. MCB uses both thermal and magnetic tripping system. The faceplate rating is usually the thermal tripping threshold, while the magnetic tripping threshold is set much higher, 3x, 5x, 10x the faceplace value depending on the MCB trip curve spec (B, C, D etc). During motor starting, when the current draw is very high, Overload Relay does't trip (yet) because the motor starting process is usually shorter than the bimetallic strip heat up time. However if the motor seizes up during starting and the high current draw is sustained, the Overload Relay bimetallic strip will heat up substaintially and trips. The downside to this is, if there is a short circuit, it will take some time to trip, so your wires can get heated up quite substaintially and there can be a risk of fire. The case with MCB is a bit compilcated because it uses both thermal and magnetic tripping. The delayed thermal tripping characteristic you see in Overload Relay is also present in MCB, so during normal motor starting it will not trip (yet), and if the motor siezes it will also eventually trip. But, once the magnetic tripping threshold is reached, the MCB will no longer use thermal tripping (which is slow) and uses magnetic tripping instead (fast). This eliminats the problem you see in Overload Relay during short circuit situation, but, as I am sure you had experience at least once in your life, MCB can be annoyingly sensitive. Proper MCB sizing therefore is a more involved process.
PLEASE MENTION THE SIZING OF CONTACT OR IN TRMS OF FLC*MULTIPLIER SUPPLY CABLE IN/OUT TO STARTE =FLC*MULTIPLIER MAIN CIRCUIT WIRES IN STARTER=FLC*MULTIPLIER.
Mam,when motor starting time the inrush high current directly passing through the mcb and contactor.so mcb is selected higher rating,why contactor is selected same to the FLC.what is the reason?
Her formulas also same if u check carefully sir For eg 1hp motor means 0.746kw Put in her formula ie HP* 0.746=kw So 1*0.746=0.746kw If 5hp motor then 5*0.746=3.73kw And if u use kw to hp then Kw/0.746=hp 3.73/0.746=5hp
kw * 1.73 =Ifl now upto 50 hp motors we take 2 times the ifl I.. e I*2 =starting current above 50 hp we take 1.5 time I * 1.5 = starting current and select the mcb or Mccb according to the starting current sharjah regulation ..
Bcoz C class mcb 5-10 times higher current carry kar sakta he.matlab 26amp ka mcb lagaya to at starting 5 times higher current carry karlega..kuch micro-sec ke liye hi 5-10 times current flow hoga
Thank you, this is a good one. A lot of tutorials forgot to include consideration of MCB trip curve characteristic in their calculation. In practice I prefer to be a bit more detailed with the trip curve calculation, but for learning this is good enough.
You have Given This Information Very Well
Good and thanks.
Thanks for this co-operation
Nice..info for beginners..ty mam🙏💐☺️
Very good video mam🎉🎉
Very nice madam❤
Thanks sister for waching video
Madam ji your video very useful
Please continue electrical technician or Eng. Work video uploaded
Madam, your channel is right on point what electrician, engineers, and technician need
Nice sister 👍, from Kerala.
informative ❤
Amazing explaination Mam
Excellent madam. Amps keliye mera formula Hp*1.34, example 10hp ka motar 10*1.34=13.4Amps isa calculate karta
Good information... Thanks....
Very well explained ma'am
Tq👌👌👌👌👏👏👏
Excellent 👌👌👌
very helpful for interview
Mam you should clearly explain about 5 which is divided. I also confused 😕
Very nice thank you
Thankyou..... Very usefull
👍
Nicely explained madam...these concepts are very useful to me ...why bcz i started electrical panel board manufacturing company ...so i request u to share ur full knowledge to me madam...tq....
Medam aap ye vali video continue karte huve SFU SELECTION OR MPCB KA SELECTION KESE KARNA HE VO BATAYE
What a beautiful explanation.... waiting for your next vedio regarding single line diagram
Yes ...I will upload soon on that ....
@@electricaldesignestimation5001 thanks
@@electricaldesignestimation5001 Please, Calculate FLC considering motor Efficiency.
Thanks...
very nixe video
Dear Madam,
You have selected MCB 26A, OLR around 16A...that's fine...
But you said in DOL, motor always draws higher current at start, (130A according to video). So that point is that how motor will continue to run even starting current is higher than MCB, OLR rating? There will be no tripping? Why? Because at start current will be higher than OLR, as well as MCB rating...
Please clear this point, thanks
instaBlaster...
In short!
Motor ka starting current initially high hota kuch mili seconds k liye(nearly 2 3 cycles me). Uske baad motor apni steady condition me a jaati h. Us initial time me high current bear krne k liye hi hum c Type mcb lete hain.
For further detail
Ap ek baar b,c and d curve MCB k characteristics study ke lo.
Understand that this is an old question, but commenting anyway in case somebody else needs this info.
In general application, there are 2 types of overcurrent detection: Thermal, and magnetic. Thermal tripping uses a bimetalic strip that, during current overload, heats up and bends. The bending triggers the trip mechanism. The heating process takes time, and this introduces a time delay into the tripping action. The higher the overload current, the shorter the tripping time, which is why this is sometimes called a "inverse time" type circuit breaker.
Magnetic tripping depends on the magnetic field strength generated by the current flowing through the circuit breaker. During overload the magnetic field is much stronger than usual, and this immediately triggers the trip mechanism. There is no time delay because change in magnetic field is immediate. This is also sometimes called "instantanous tripping".
Overload Relay (low to medium spec models) exclusively uses thermal tripping system. This is why, in certain countries like mine, overload relays are more commonly called Thermal Relay.
MCB uses both thermal and magnetic tripping system. The faceplate rating is usually the thermal tripping threshold, while the magnetic tripping threshold is set much higher, 3x, 5x, 10x the faceplace value depending on the MCB trip curve spec (B, C, D etc).
During motor starting, when the current draw is very high, Overload Relay does't trip (yet) because the motor starting process is usually shorter than the bimetallic strip heat up time. However if the motor seizes up during starting and the high current draw is sustained, the Overload Relay bimetallic strip will heat up substaintially and trips. The downside to this is, if there is a short circuit, it will take some time to trip, so your wires can get heated up quite substaintially and there can be a risk of fire.
The case with MCB is a bit compilcated because it uses both thermal and magnetic tripping. The delayed thermal tripping characteristic you see in Overload Relay is also present in MCB, so during normal motor starting it will not trip (yet), and if the motor siezes it will also eventually trip. But, once the magnetic tripping threshold is reached, the MCB will no longer use thermal tripping (which is slow) and uses magnetic tripping instead (fast). This eliminats the problem you see in Overload Relay during short circuit situation, but, as I am sure you had experience at least once in your life, MCB can be annoyingly sensitive. Proper MCB sizing therefore is a more involved process.
Nice @@marcheck3400
for MCB rating selection why we divide by 5 to starting FLC?
Very nice explanation..thanks
Thank you sister good explanation 🙂☺️
Please make your videos in English especially this one.
Thank you. explanation is good
Type 2 coordination chart according kiya ji hai na
55 kw motor k liye agar 2 se multiply karnge to 110 amp aayega but flc-96 amp hai fir kaise calculate kare
Thanku ma'am and switchgears control panel study in ee and eee .
❤❤❤tq mam
Aap MPCB or MCCB se selection batao
Thank you mam, waiting for more video
Very nice explanation thanks
Thank mam
Please explain cable sizealso taking7.5 kw as example
Nice ma'am
💐👍👌
♥♥♥♥♥
MCB Selection me 130/5
5 kya hai
madam industrial equipment vfd's transformers's vcb sf6 breakers oprating system to explaned
From dubai see
👍💐
MCB type
A , B , c, D, z curve
Nice video
Cut to cut clear
Make more videos for mcc panels🙏
Why we have to multiply by ten then divide by five
please upload more videos
PLEASE MENTION THE SIZING OF CONTACT OR IN TRMS OF FLC*MULTIPLIER
SUPPLY CABLE IN/OUT TO STARTE =FLC*MULTIPLIER
MAIN CIRCUIT WIRES IN STARTER=FLC*MULTIPLIER.
THANK YOU. PLEASE GIVE DETAIL FOR SIZING OF SPARES TO AUTO TRANSFORMER STARTER & SIZING OF IN& OUT CABLES FOR ALL CONTROL PANELS
Good knowledge sharing for interview
Mam,when motor starting time the inrush high current directly passing through the mcb and contactor.so mcb is selected higher rating,why contactor is selected same to the FLC.what is the reason?
I love u.pls reply
madam ... 1 HP = 0.746 kW
Her formulas also same if u check carefully sir
For eg
1hp motor means 0.746kw
Put in her formula ie
HP* 0.746=kw
So
1*0.746=0.746kw
If 5hp motor then
5*0.746=3.73kw
And if u use kw to hp then
Kw/0.746=hp
3.73/0.746=5hp
Like🥀🥀👌👌
Why you decide by 5
13.05×10 esme 10 value kiski he
very Nice
√3 keya hai plz batao
3phase
Thank u madam thanks
13.05/5 esme 5 value kiski he
wow
Why you devided by 5
Good
1.732
pls, Ma'M make more video, Please..
Mam 1phase and 3phase load calculation for domestic and commercial ke liye NIKALNA bataiyega mam nice video
1 HP = 0.746 KW
Madam j aur k curve v hote h
Medam cable ka load calculation bataye
kw * 1.73 =Ifl
now upto 50 hp motors we take 2 times the ifl I.. e I*2 =starting current
above 50 hp we take 1.5 time
I * 1.5 = starting current
and select the mcb or Mccb according to the starting current
sharjah regulation ..
5 hp not 50
735.5
How to select mccb for starters
No protection for contactor when Shor circuit.....
I WANT TO KNOW THE SIZING OF SPARES, CONRACTORS, OLR MAIN& CONTROL CIRCUIT WIRES TO ALL DOL, STAR&DELTA,ATS,RRS,VFD&VFD ETC.
KW To HP ?
KW × 1.341
HP To KW ?
HP ÷ 1.341
Never rely FLC on twice of kW, you r giving wrong information
130/5 for MCB rating clcultion , where u got 5?
I have also same doubt
Pls reply mam
Bcoz C class mcb 5-10 times higher current carry kar sakta he.matlab 26amp ka mcb lagaya to at starting 5 times higher current carry karlega..kuch micro-sec ke liye hi 5-10 times current flow hoga
@@siddharthsorathia5449 right
Why 130 dividing by 5
Could you speak in English???
Mam.. I know only English
Your surge current calculation is wrong ..... It's not 10 times .... FLC...
why volt is 415. what about phase.if volt is 415. insufficient information,
Whatsapp grup hai ji
Very nice
for MCB rating selection why we divide by 5 to starting FLC?
Because min will be 5 times so we will devide by 5