Hi guys, i just changed a 8.5kw electrical shower for a friend, the live is 6mm2 and i believe it is fine, the only thing is the cpc, looks like 1.0mm, at most 1.5mm, i checked codes, but still not sure about it, is this cpc ok?
cheers
Can someone please tell me if i have done this correct.
Got a fuseboard change and the tails are 16mm sinlges fed from an 800kmf with a 6mm single main earth.
Board is other side of house to meter so a pain to upgrade main earth.
Done the adiabitic and it comes out as follows.
Supply is tnc-s...
Hi folk’s adiabatic equation, help / advice
S = Size of earth bonding conductor required.
I = pfc in amps.
t = disconnection time in seconds.
K = values in table 43.1.
I am trying to work out if a 6mm main earth is adequate on a TN-C-S system
Is the 6mm cpc in the 16mm T&E allowed?
Have been...
I have just done a periodic on a flat that is supplied by 16.0mm pvc T&E (6.0 mm cpc only earth conductor) on a 60A 1361 switch fuse on a TN-S system. The DB Ze at the flat is 0.21 No matter what way i'm doing my sums i cant seem to get what i think is the right answer. I get 3.01mm minimum...
Hi Guys my question is with relation to the adiabatic equation, I am aware that the following is true.
S = Size of earth bonding conductor required.
I = pfc in amps.
t = disconnection time in seconds.
K = values in table 43.1.
If I am trying to work out if a 6mm gas and water bond is...
Hello, got my Elecsa assessment on 4th january, going to change the cu in my house and use that as assessment job, its simple as only 3 circuits, sockets, lights and shower. But shall i tell building control?? Elecsa said upto me, they dont request it but they will let building control know...
Hi all!
When you are designing new circuits, do you design for both overload and fault protection for every case? Or for fixed loads design without overload protection and make adiabatic check as well?
Hello
Does anybody know if 'I' in the equation relates to PSCC or PEFC.
GN3 seems to point to PEFC, but reg 543.1.3 seems to suggest PSCC.
Any ideas?
Thanks
Recent pir i did last week ring main 2.5mm and cpc 1mm so using the equation
If =Uo/Zs=230/0.82=78673.183 so this is my fault current sq root of =15734 x time(type b32 amp)0.1s divided by 115
88.69/115=0.77 so 1mm is cool
looking at app 3 pg 249 in bs7671 cannot seem to see the time...
Could anyone just confirm my results for adiquate earthing size and calculation using the adiabatic equation...
My test was on a ring main circuit wired in 2.5/1.5 pvc..
My supply voltage is 247v
My Impedance is 0.38 ohms.
The circuit is supplied via a RCBO 32a C type
My results suggest that a...
Could anyone just confirm my results for adiquate earthing size and calculation using the adiabatic equation...
My test was on a ring main circuit wired in 2.5/1.5 pvc..
My supply voltage is 247v
My Impedance is 0.38 ohms.
The circuit is supplied via a RCBO 32a C type
My results suggest that...
Does anyone do the adiabatic equation to check earthing conductor size is okay, as we've just been taught it at college and its very good to know. My question is, do you actually check this in the field or just take it for granted?
Thanks in advance for all responses.
Hi All,
Can anybody help....Trying to establish if I would have to change the mec on a TNS system....
Ok So S=sqr(I2xt)/k
When establishing the value of 't' do I use the characteristics of the distibutors main fuse or the main switch in the CU or I have missed the point entirely?:rolleyes...
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