No corny, irritating music playing and the content delivered to perfection - great educational videos.

As someone who is about to do the testing courses I found these videos extremely helpful. Thank you

Your videos have helped me to study and pass the Red Seal Construction Electrician exam in Alberta Canada...Thanks very much indeed, JW.

Love your videos, Would be good to see more on 3 phase

It's pretty important to have phase correct especially on compressors where if it were wired wrong the compressor will run but the oil pump will be blowing bubbles into the sump instead of pumping oil through it, this is why compressors have the direction cast into the flywheel or crankcase.

Interesting. Here in the US, black, red, blue is typical for 208/120 -- brown, orange yellow for for 480/277. White or gray are used for neutral.

Thanks for the great video! As I've seen here in South Africa, the phases may not always be in the correct sequence. For example, my house has the red and blue swopped right up on the street pole. Always been like that. It's some sort of mix up between Eskom and municipal wiring changes. For municipal, on the 4 span overhead feed it should be neutral on the street side, then red, white, blue. But Eskom had neutral in the same place, then blue, white, red. The main feed from the transformer was replaced at some point and is now the municipal wiring whereas the house feed is the Eskom wiring. The only difference it makes is for the 3 phase borehole pump (changes the direction of rotation), but again it shows why it's important to test phase rotation (even on existing installations).

totally agree with you John on old 3 phase colours they where so much safer.

Thank you, needed to change rotation on socket and this video was helpful, have a good day sir!

Beautifully explained.

To be fair, JW, I've never seen a three phase motor with a neutral connected to it in the whole time I've been an electrician. We always wire them in star as 400V. And there is no out of balance current.

I always find it intresting how the countries develop with the phases. Around here for a long time the power companies will only deliver three phase to your premise, and you basically find single phase only in apartments where it was chosen to distribute different phases to different apartments.

Fantastic video, thank you.

Thanks John, this explains it perfectly!

Interesting John. Since I left the UK where was an electrician there are changes happening all the time. Never heard/ saw a phase sequence detector. If a motor ran the wrong way we change any pair but I see your point that sometimes you would need to know straight away before some machine got damaged if the rotation direction was wrong. Also the single phase voltage was 240, now 230 but the tolerance still allows 240 as its in range. The colours of 3 phase were red, blue and yellow ( sometimes white). ( My spell check here in the US is flagging colour as wrong, it wants color) The line to line was 415 v ac. Now about 400 eh. Times change.

Hi John could you do a video explaining how 3 phase works please From what I understand on a balanced load you don’t need a neutral but where does the current return ? Is it split between the other phases. Thanks

thank you for your videos, i find your diagrams and explanations easy to follow and grasp the concept in my head, your an angel may god bless you x

I'm testing our industrial power grid and power extension cables/cords 400V (3x 230V) with 1 capacitor (2uF/400V) and 2 light bulbs 220V/60W (all three things connected in star connection). First light bulb lights more than other... If phase sequence is reversed, the second bulb lights more than the first. Works fine. engineering.electrical-equipment.org/energy-efficiency-motors/checking-phase-sequence-3-phase-supply.html

How can I identify the ungrounded conductors color at a M-box?? I know they are black, red and blue but they are all black now. Would appreciate any help Thanks

Thanks for sharing, great content, to the point and efficient. You might crank out a Bach prelude there on that organ to close the show....:)

Hi John Love the Clips, have a question for you have you any experice or tested a Di-Log DL9110 Multifunction tester ?

this is the 1st time I watch your video, somehow I believe that I heard your voice somewhere else before

thank you SIR!

Thanks JW

If I were to measure the phase rotation of a 12.4kV Switchgear, I’d want to do that on a aux power panel that is connected to a 12.4k/120V PT/CT?

Hi JW love your videos, not sure where you are based but I’m pretty sure “normal” phase rotation here in the north east is anti-clockwise.

Interesting. A few years ago we had a negative line fault from the power cables in the street. So we got that 400+ volts into the house, as did some of my neighbours. Lots of damage caused. Lots of time for all the repairs to.

Clockwise is mandantory. If it's counter-clockwise motors are rotating in the wrong direction. In case of a circular saw this could be very nasty. The saw blade could turn loose and fly away with much power. Nothing anyone wants to see...

I picked up one of those electro-mechanical phase rotating indicators at a church table sale. Your video confirms what it is. I thought it was for phase rotation testing, but all the instructions were in German. Looks to be dating from the 1970's at a guess. Were any units made with lamps that illuminated in rotation?

I believe in North America, the phase colours are black, red, and blue. The neutral, when used, is white.

thank you

Thank you for the video :)

John, Why in 3 phase installations is the voltage always refered to as "415 Volts 3 phase" but if my maths serve me correctly (Based upon single phase supply being 220 Volts) the total voltage between all three phases add up to 460 Volts? This may be a really obvious answer, but I've never been told! (Even though I am a qualified PAT tester!!!) Thanks Clive

How can you tell wich of all thee cables is l1 l2 l3 is not marked on the disconect box

How can I recognise which is L1, L2 and L3? No different colours on the cables

Is there a way to check that the phase sequence is correct without a phase sequence tester? Without looking at the colours and matching them up at each end (supply to motor) I wouldn't have a clue which phase was which. 0_o

There phase colours in New Zealand is red white and blue with back neutral labels L1, L2 and L3

Jw do you have any information regarding the AM2 test to get the J.I.B card, eg practical and theory

Hello I am watching your video all the time it's rely helpful & I have a question. How to check 3 phase ELCB by easiest way I don't have device to checked it , can you show me simple methods & thanks again , hope I can have the answer .

I've seen 690v isolators when walking through some buildings and also on testers such as your own one but I'm just wondering what that figure is there for as I'm positive they're 400v incomers from the dno. Is it just the rating of the isolator or did 690v used to be a supply voltage? Thanks

i was looking in a 3 phase board yesterday with 2 three phase circuits in, one circuit was brown,black,grey and the other circuit was black brown grey, why would this have been could it it jut preference to the colour in the SWA or was that to do with phase rotation ?

Obiously the earth is green and yellow but on a 4 pin plug, What lives will brown, black and blue go on for a bridgeport mill? (live1,2and3). My converter states the hot wires must go on live 1 and 3 what colours would these be out of black brown and blue?

HOW CAN FIND WINDING IN 9 LEAD 3 PHASE, AND WHAT MAKE A DIFFERENT BETWEEN STAR DELTA CONNECTION MOTOR AND DELT STAR CONNECTION MOTOR. MANEY THANKS . VAHID

can u do a video on how to wire emergency lights a wiring diagram would be great

Sir how about the red black and white?

What would the voltage be on a delta supply. I know phase and line voltage is the same so are all 3 phases 240 or are each phase 400

Question sir John, Can we identify the rotation of the motor without connecting it to the supply?

Cheers!

Hi, I have a plug its perhaps Swedish or german and has T, S, R written on it in place of L1 L2 and L3 might you know the sequence I have wires brown black Gray so they are ready

Wouldn't a portable scope with a 1000 volt probe work well for that too

Hello sir,Thank you for your great videos, I’v a refrigeration compressor works and then stops for less than a minute and when measured the current for 3 phases, I noticed L2 giving a very high current "3 times the normal value" and L1 and L2 normal, what is expected to occur this problem, Even though there is a failure phase sequence in the circuit.

Nice video..... Love from Pakistan

is it a 120 or 180 degrees off set?

Without meter phrase sequence check pl explain

GOOD VID

Can I as why you refer to the harmonised colours as 'unhelpful' John ?

Hello sir . Single phase preventer how to work in HVAC please explain to me. thanks

u forgot to highlight d high leg phase. when using the meeting

And how do you test phase rotation? Lol

why do you lower your voice intermittently while speaking ?

your volume goes up and down hard to hear

thu nodakin henama gahapiya

50% wrong and 50%right If you want to discuss me reply me