I have been going round in circles with this question. I just cant seem to get an answer remotely close to the options.
Continuity of a ring final circuit has been tested as part of an initial verification of a new primary school. All the socket outlets are connected directly to a ring.
The circuit is 58m long, wired in 4 mm2 live and 1.5 mm2 cpc flat profile cable. The circuit is protected by a 32 A BS EN 60898 Type B circuit breaker.
What is the expected r1 value?
0.27Ω
0.32Ω
0.43Ω
0.52Ω
So I have got the R1+R2 value from the OSG which is 16.71 mΩ/metre
I have multiplied this by the 58 metres equaling 969.18 mΩ
I have times by 4 for the r1+r2 value 3876.72 mΩ
I have then multiplied this by the 4 to 1.5 ratio which is 0.273 equaling 1058.34 mΩ
I then divided by 1000 to get ohms
My answer is 1.05. No where near any of the answers.
What am I doing wrong?
I'd appreciate any help with this. I don't want the direct answer, just how I'm screwing it up.
Thanks in advance.
Continuity of a ring final circuit has been tested as part of an initial verification of a new primary school. All the socket outlets are connected directly to a ring.
The circuit is 58m long, wired in 4 mm2 live and 1.5 mm2 cpc flat profile cable. The circuit is protected by a 32 A BS EN 60898 Type B circuit breaker.
What is the expected r1 value?
0.27Ω
0.32Ω
0.43Ω
0.52Ω
So I have got the R1+R2 value from the OSG which is 16.71 mΩ/metre
I have multiplied this by the 58 metres equaling 969.18 mΩ
I have times by 4 for the r1+r2 value 3876.72 mΩ
I have then multiplied this by the 4 to 1.5 ratio which is 0.273 equaling 1058.34 mΩ
I then divided by 1000 to get ohms
My answer is 1.05. No where near any of the answers.
What am I doing wrong?
I'd appreciate any help with this. I don't want the direct answer, just how I'm screwing it up.
Thanks in advance.