A company I worked (long since gone bust) for when I was an apprentice got this wrong. It was a fairly small plant room with 3 phase motors, rotork actuators and other control and instrument equipments plus lighting etc. The main tray was 300mm wide and stacked full. I heard in theory at college cables get warm in groups etc but this was the first time I experienced it I was quite surprised how warm they all were. Me and a labourer were the ones tasked with replacing the 300 tray with 600 all while the stuff was powered on.
@@efixx i spotted the gutter bolt but couldn't resist :) .. i think who ever done it deserves an eFIXX i got it wrong sticker on the next live feed hahahaha
Not forgetting spare capacity, as we are designing for the future installation also. I would always size at the maximum grouping likely to be experienced on the containment and/or DB. With all the caveats on the British Standard its hardly worth trying to wiggle your way around the minefield, especially if the cable size you get in the end is reasonable (such as required for voltdrop). On occasions where a larger than reasonable cable is calculated look at it in detail to see if it can be engineered down.
Interesting. I've worked in London underground tunnels where HV cables are mounted to trays and or a rack system. Almost every time they're grouped together with zero distancing between them
Amazing videos as always. Did the fine people at eFixx create more videos regarding grouping? The area is complex, especially the notes under 4C1 table. Not sure how Note 1: "These factors are applicable to uniform groups of cables, equally loaded" works. For a an installation where only smaller width cable trays are possible, the ratings factors push for 25mm CSA cable for radial sockets... i must be doing something wrong, can anyone help please!?? I am a qualified apprentice on my final portfolio . thanks
Would this even apply to a tray like the one behind you. ? Isn't there a section of the grouping that states , if the cables are more than their diameter apart they aren't classed as being grouped ?
Table calculations did change as the oven and the hob changed we calculated for 4.74kw but then she one decided to buy a 6.5kw hob. We had a total of 8kw on full load. But we did have 6mm total length was under 14M so did calculate for 15M All Well with in using mV drop from the big book of you must follow or else.
hi , nice video and explanation. i learn so much from your videos. please make the explanation about the unequally loaded and not same size conductor grouping factor, thank you
@@efixx saw a shop today with the eFix logo black on white back ground, I think it was a print shop or something , it in Southend . Maybe a copy right issue there . Can you call me please I emailed you my number last week
@@efixx say there is a large installation with 20 circuits in trunking leaving the DB. That would mean a grouping factor is 0.38… this would make every cable need to be very large, nevermind if other factors were applicable ? Is this right, anyway around this?
If 35C Temperature Factor (0.94) And Load 4A Lighting 2# circuit (0.8) MCB 10A --- It= 10/(0.94x0.8)=13.3A I need 1.5 Wire The wire can carry 17.4A ------ Question: What will be the answer 1- 0.3(0.8)(17.5)(0.94) Or 2- 0.3(0.8)(17.5) Or 3- 0.3(0.8)(13.3) Thank you
I am one of your followers from Algeria Thank you for the valuable information that you provide for free I appreciate your effort to provide the content but sir If you translate into Arabic, you will gain more followers just an opinion
A company I worked (long since gone bust) for when I was an apprentice got this wrong. It was a fairly small plant room with 3 phase motors, rotork actuators and other control and instrument equipments plus lighting etc.
The main tray was 300mm wide and stacked full. I heard in theory at college cables get warm in groups etc but this was the first time I experienced it I was quite surprised how warm they all were.
Me and a labourer were the ones tasked with replacing the 300 tray with 600 all while the stuff was powered on.
Thanks for sharing your experience, turns the theory into practical. 👍
missed a cable tie 3rd row up far right 1:06 had to be done before some else got in haha, great video as always Joe
Ha! Good spot. There was a fixing screw in the way in fairness.
@@efixx i spotted the gutter bolt but couldn't resist :) .. i think who ever done it deserves an eFIXX i got it wrong sticker on the next live feed hahahaha
Not forgetting spare capacity, as we are designing for the future installation also. I would always size at the maximum grouping likely to be experienced on the containment and/or DB. With all the caveats on the British Standard its hardly worth trying to wiggle your way around the minefield, especially if the cable size you get in the end is reasonable (such as required for voltdrop). On occasions where a larger than reasonable cable is calculated look at it in detail to see if it can be engineered down.
Hi, where can i watch the second episode regarding non equally loaded wiring int trunking. Thanks
Interesting. I've worked in London underground tunnels where HV cables are mounted to trays and or a rack system. Almost every time they're grouped together with zero distancing between them
Much lower current on the HV
Curious to know where HV cables are used in LU tunnels?
Sir you just save my butt from getting fired
Amazing videos as always. Did the fine people at eFixx create more videos regarding grouping? The area is complex, especially the notes under 4C1 table. Not sure how Note 1: "These factors are applicable to uniform groups of cables, equally loaded" works. For a an installation where only smaller width cable trays are possible, the ratings factors push for 25mm CSA cable for radial sockets... i must be doing something wrong, can anyone help please!?? I am a qualified apprentice on my final portfolio . thanks
Interested to know grouping factor is necessary for DC cable for UPS which will only discharge max 7 minutes at a time?
From where you got thar table for grouping factor? IEC or NEC ?
Does table 4c1 also apply to T&E cables?
Can you do a video on how a realistic maximum demand is calculated for EV installs specifically.
Yes - more on EV coming very soon!
I've usually left the job. 5 years before the grouping factor comes into account 🙄
Would this even apply to a tray like the one behind you. ? Isn't there a section of the grouping that states , if the cables are more than their diameter apart they aren't classed as being grouped ?
More than twice the diameter apart if memory serves. 👍
@@efixx ahh yes . Just looked it up. You are correct. Cables spaced 2 times their diameter apart are classed as not grouped.
Nice, good to know the old brain's still ticking over!
Table calculations did change as the oven and the hob changed we calculated for 4.74kw but then she one decided to buy a 6.5kw hob. We had a total of 8kw on full load. But we did have 6mm total length was under 14M so did calculate for 15M All Well with in using mV drop from the big book of you must follow or else.
Great video
Thank you. 😊
hi , nice video and explanation. i learn so much from your videos. please make the explanation about the unequally loaded and not same size conductor grouping factor, thank you
Just Done my covid 19th edition.
Fantastic video low as always
👍👍👍❤️⚡️
Thanks Sean.
@@efixx saw a shop today with the eFix logo black on white back ground, I think it was a print shop or something , it in Southend . Maybe a copy right issue there . Can you call me please I emailed you my number last week
@@efixx say there is a large installation with 20 circuits in trunking leaving the DB. That would mean a grouping factor is 0.38… this would make every cable need to be very large, nevermind if other factors were applicable ? Is this right, anyway around this?
If 35C Temperature Factor (0.94)
And Load 4A Lighting
2# circuit (0.8)
MCB 10A --- It= 10/(0.94x0.8)=13.3A
I need 1.5 Wire
The wire can carry 17.4A
------
Question: What will be the answer
1- 0.3(0.8)(17.5)(0.94)
Or
2- 0.3(0.8)(17.5)
Or
3- 0.3(0.8)(13.3)
Thank you
Callout electricians are exempt from these rules ...
We just take a sharp intake of breath. And give the client the bad news.
£300ph
@@edglue6138 Thats good!
@@Mike_5 iz it?
Get to bed.
You have a stack of boring vids to edit in the morning.
Gaz Ronsin on the production
I am one of your followers from Algeria Thank you for the valuable information that you provide for free I appreciate your effort to provide the content but sir If you translate into Arabic, you will gain more followers just an opinion
Massive thanks for the support 👍🏻
wwwwwwwhhhhhhhaaaaaaaatttttttt!!! I didn't understand any of that it's a good job I'm not an electrician.
😂 Time to retrain! 👍
I've forgotten your name.
is it OK to call you Dandelion hair?
😂 Savage! But sure.
@@efixx cheers Dand
Check the code 🙄
🤔