Not sure if you guys will see this but just wanted to say a massive thank you, passed my AM2 first time and your videos absolutely carried me through, thank you!!!
My level 3 teacher is currently drilling me with three phase testing and fault finding as Iv handed my design project in well early. I’m so glad because once you start doing the three phase it’s so much different. I can honestly say I feel confident to do my 2391 and am2 and watching these videos now make a lot more sense than when I watched it without doing three phase.
== 🕐 Time Stamps - Cut to the action 🕕 == 00:00 - Ze and PFC tests 00:54 - Isolating the 3 phase distribution board 01:58 - Disconnecting the earthing conductor to remove parallel earth paths created by the bonding 02:55 - External earth fault loop impedance test Ze test on a 3 phase dis-board 05:11 - Reconnect the earthing conductor 05:19 - Prospective earth fault current PEFC test (PFC) 06:34 - Prospective short circuit current PSCC test (PFC) 08:00 - Rule of thumb double your highest reading from PSCC test for a 3 phase supply 09:48 - Testing PSCC between the 3 line conductors of a 3 phase supply
Great video! Lots of real world training missing online. H&S… I wear VDE gloves when working/testing live. Just mitigates the risk. Easy enough to fall forward on to the live terminals, especially so on older 3ph boards & working off a ladder, etc..
Great video guys! Not sure how strict and to the book the assessors will be in the am2 but GN3 does recommend dividing the line to line value by 0.87 if measuring Ipf between phases. Edit: After some research online I believe this figure is a guide to working out a simultaneous fault between all phase conductors with a fault of negligible impedance.
Thank you so much for these videos. Really helpful information! One question. Why we take the PFC measurement with the main switch off and on the source side? When using the system all breakers etc are on. Why take the rest of the system out of the equation? the PFC surely would be different when the whole system is connected and turned on? Thank you
Excellent Video! Very well explained. I have just one question please to clear my mind. In theory, line to line fault is 3phase fault multiply by 0.866, therefore can I just use the fault current measured in L-L (4.11 kA) divided by 0.866 to get the 3phase fault instead of doubling the max fault measured in L-N?
Good video, informative. After 29 years of data cabling/engineering a flooded market of poor quality engineers the last few years reducing rates I started an electrical training course a month ago and enjoying it (should of started years back). Would the incomer earth be better with a ring crimped connector?
I do believe the highest L-L reading has to be divided by 0.87 to get a simultaneous 3 phase fault PSCC. Someone else also mentioned this. Was there a reason you didn’t mention it in this video?
I’m assuming as it’s a live test you’d need the tails to have voltage to actually get a reading on the Ze and PFC tests? For example on the AM2 rig if they’ve isolated it remotely, I’d need to lock off the main switch on the board, then energise the isolator?
Does that earth wire go back to supply transformer or is it just linked to the neutral at the cut out. Is 3 phase the same as single phase domestic in this regard. Thanks
On a TN-S the earth goes all the way to the transformer separately from the neutral,. They're then connected together at the transformer. On a TN-C-S (shown in the video) the earth and neutral are joined at the cutout, and continue as a "PEN" conductor to the transformer (protective earth/neutral). On a TT the earth doesn't go to the transformer at all. Instead it connects to the consumer's earth electrode.
Sorry if this is silly question as I’m still a beginner adult learner etc but why do we have to use a,,3lead high or 3lead low? what’s difference and why do it etc 👍👍
No, the Zmax function is only used to record the highest Zs reading on the screen when you’re carrying out multiple Zs tests. For example, a ring main consisting of 8 sockets. I hope this helps 👍🏻
for the am2s would we need to test between line conductors for PSCC or is testing between line and earth and line and neutral and doubling it enough ? Also would the reading from line and earth ever be higher than line to neutral ?
I can hear you Clem. Technically if you measure line to line you should then divide by 0.87 to account for the bolted fault shorting all lines at the same time that you describe! Doubling the line neutral pscc accounts for this already. Hope that helps. 👍
Even if you had a three way fault - which is a two fault situation so we don't usually consider these. But the three phases are like the corners of an equaliateral triangle - so each is 400V from each other. When you short all three you'd get approximately the same fault current on each line conductor as the additional current would be balanced across three instead of two conductors.
Not sure if you guys will see this but just wanted to say a massive thank you, passed my AM2 first time and your videos absolutely carried me through, thank you!!!
Fantastic news 👍🏻 congratulations from team GSH
Yes, thanks guys, about to undertake this myself and your videos are invaluable 👊
@@GSHElectrical He should have done Zs at DB as well...
@@Dailymailnewz isnt that only relevant if this is a sub main ?
My level 3 teacher is currently drilling me with three phase testing and fault finding as Iv handed my design project in well early. I’m so glad because once you start doing the three phase it’s so much different. I can honestly say I feel confident to do my 2391 and am2 and watching these videos now make a lot more sense than when I watched it without doing three phase.
All the best and thanks for commenting 👍🏻
the best demostration i found on YT so far , Cheers
Massive thanks to
== 🕐 Time Stamps - Cut to the action 🕕 ==
00:00 - Ze and PFC tests
00:54 - Isolating the 3 phase distribution board
01:58 - Disconnecting the earthing conductor to remove parallel earth paths created by the bonding
02:55 - External earth fault loop impedance test Ze test on a 3 phase dis-board
05:11 - Reconnect the earthing conductor
05:19 - Prospective earth fault current PEFC test (PFC)
06:34 - Prospective short circuit current PSCC test (PFC)
08:00 - Rule of thumb double your highest reading from PSCC test for a 3 phase supply
09:48 - Testing PSCC between the 3 line conductors of a 3 phase supply
Great video!
Lots of real world training missing online.
H&S… I wear VDE gloves when working/testing live. Just mitigates the risk. Easy enough to fall forward on to the live terminals, especially so on older 3ph boards & working off a ladder, etc..
Another great video and demonstration, much appreciated
Thanks 👍🏻
Thanks guys make it so much easier to understand seeing it 👍🏼
100% agree.
100% agree.
Thank you guys for all test. Some of them I wasn't sure 👍👍👍
Thanks for the support and watching
Молодцы ребята,очень полезная информация 👍👍👍
It was more than helpful, God bless u
Thanks 👍🏻
Thanks ,you make it easy to understand
Thanks for commenting and watching 👍🏻
Thanks very much, been looking for a good ze, pfc vid in a 3p DB. Getting ready for my fica at the end of this year👍🏾.
Thanks
Plz do many more videos. Great job chaps
Thanks! Will do!👍🏻
Great video guys! Not sure how strict and to the book the assessors will be in the am2 but GN3 does recommend dividing the line to line value by 0.87 if measuring Ipf between phases.
Edit:
After some research online I believe this figure is a guide to working out a simultaneous fault between all phase conductors with a fault of negligible impedance.
Great feedback 👍🏻
Great Video Guys, very well explained
Thank you for the explanation
Thanks for watching 👍🏻
Thank you so much for these videos. Really helpful information!
One question. Why we take the PFC measurement with the main switch off and on the source side? When using the system all breakers etc are on. Why take the rest of the system out of the equation? the PFC surely would be different when the whole system is connected and turned on?
Thank you
massive thanks !
👍🏻
Excellent Video! Very well explained. I have just one question please to clear my mind. In theory, line to line fault is 3phase fault multiply by 0.866, therefore can I just use the fault current measured in L-L (4.11 kA) divided by 0.866 to get the 3phase fault instead of doubling the max fault measured in L-N?
Brilliant guys
Thanks
I didn’t double the figure and I failed on the PFC test so I had to resit the full inspection and testing segment
Thanks for your feedback 👍🏻
Great video, possible to do video on 3 phase rcd 300mA
Good video, informative.
After 29 years of data cabling/engineering a flooded market of poor quality engineers the last few years reducing rates I started an electrical training course a month ago and enjoying it (should of started years back).
Would the incomer earth be better with a ring crimped connector?
I do believe the highest L-L reading has to be divided by 0.87 to get a simultaneous 3 phase fault PSCC.
Someone else also mentioned this. Was there a reason you didn’t mention it in this video?
Why 0.87?
I’m assuming as it’s a live test you’d need the tails to have voltage to actually get a reading on the Ze and PFC tests? For example on the AM2 rig if they’ve isolated it remotely, I’d need to lock off the main switch on the board, then energise the isolator?
Does that earth wire go back to supply transformer or is it just linked to the neutral at the cut out. Is 3 phase the same as single phase domestic in this regard. Thanks
On a TN-S the earth goes all the way to the transformer separately from the neutral,. They're then connected together at the transformer.
On a TN-C-S (shown in the video) the earth and neutral are joined at the cutout, and continue as a "PEN" conductor to the transformer (protective earth/neutral).
On a TT the earth doesn't go to the transformer at all. Instead it connects to the consumer's earth electrode.
great video , big thumbs up and i want that red car , where is this filmed
Thanks for the support 👍🏻
Sorry if this is silly question as I’m still a beginner adult learner etc but why do we have to use a,,3lead high or 3lead low? what’s difference and why do it etc 👍👍
Great video, once again. Could you tell me how too test a 3phase rcbo please?
Thank you!
2 kings ❤
Brilliant
Hi thanks for this I didn’t realise you have to double the PFC, is this just on a three faze board?
Yes 👍🏻
@@GSHElectrical thank you! is the PFC is the only one you write down on the schedule of tests?
@@OllyDunne24 you write down the highest reading you get out the two I believe
Thanks
Hi, would I have to carry out the PSCC between phases on a 3ph db. Or just each phase to neutral and double it?
Don’t you have to actually times by square root of three and not double it For three phase PFC? It’s not double to work out single to three phase?
Theoretically the value is x1.73. However is much easier to double it
👍🏻
Should the right hand side dial be set on zmax when doing pscc 2lead high?
No, the Zmax function is only used to record the highest Zs reading on the screen when you’re carrying out multiple Zs tests. For example, a ring main consisting of 8 sockets.
I hope this helps 👍🏻
Would you double it on a domestic install as well?
Only on 3 phase installation 👍🏻
Only on 3 phase Because of the potential between 2 different phases
Show how to measure insulation and RCD.
do you have to test between L1-L2 and so on or can you just do the L’s -N and double it?
If your tester can test between line conductors you take that as the heights reading if not it’s line neutral and double it 👍🏻
for the am2s would we need to test between line conductors for PSCC or is testing between line and earth and line and neutral and doubling it enough ? Also would the reading from line and earth ever be higher than line to neutral ?
Should be times by square root of three I thought becuase of the different between Line and Phases?
Just failed my 2391 because i got lost at the PEFC testing. Isnt there a 3 lead test with this megger or thats just for single phase
pfc requires a 2 lead test
Hi, why do you bother testing the PEFC on 3 phase if it doesn’t get recorded?
Great point 👍🏻
Ma'am bahut accha padte hai m
What about if there is an rcd when taking the pscc, is there a way to test this on a 3 low setting?
In guidance note 3 the PEFC shows a 3 lead test. does it matter if you do a 2 or 3 lead test?
i have my AM2 in 2 weeks. Thanks
I’ve always done a 3 lead test, seeing this has thrown me and I have my AM2S in a week and a half. How did yours go?
Why double why not tripple...surely if the armoured was destroyed and 3 phase was shorted with the netural it would be higher than doubled?
If I'm right you can only sort between 2 lines so line voltage is 400V giving highest fault current possible. E.g 400V ÷ 0.10ohm =4000A
I can hear you Clem. Technically if you measure line to line you should then divide by 0.87 to account for the bolted fault shorting all lines at the same time that you describe! Doubling the line neutral pscc accounts for this already. Hope that helps. 👍
Even if you had a three way fault - which is a two fault situation so we don't usually consider these. But the three phases are like the corners of an equaliateral triangle - so each is 400V from each other. When you short all three you'd get approximately the same fault current on each line conductor as the additional current would be balanced across three instead of two conductors.
@@keirstitt8277 not according to the iet you wouldn't... It's in GN3 👍
@@travoltasbiplane1551 you must have a different GN3 because it doesn't say any such thing in there.
Appendix 14 of BS7671 maybe.
Would you fail if you measure PSCC on the load side of the main switch?
if its locked off you cant
👍👍👍👍👍👍
On the am2 you don’t test for the zs you calculate it, this can fail you
This test is external impedance Ze 👍🏻.
l not have 2 phase l good vid Brilliant
What is AM2 ?
An end point assessment for apprentice electricians 👍🏻
Where’s your lock off kit 👿
great video guys, and surprised me how fluentJean Reno in english
No lock on your board. Safe isolation .
Bla bla not useful
Thanks