How do you IR test a ring main?
How do you IR test a ring main?
To test a ring you must firstly measure the end to end resistance of L-L, N-N and E-E. You should then connect the incoming live with the outgoing neutral and measure the resistance at the furthest point in the circuit. Then also the reverse of the with the outgoing live to the incoming neutral.
What is r1 r2 electrical testing?
For each outlet on a circuit, the resistance of both the live and earth conductors together (R1+R2) is measured back to the source. This test also helps identify polarity problems – for example, if a live wire has accidentally been switched with a neutral wire somewhere in a circuit.
How do you work out r2?
The R-squared formula is calculated by dividing the sum of the first errors by the sum of the second errors and subtracting the derivation from 1.
What is a r1 r2 test?
At what point of the circuit do you test R1 R2?
On a ring circuit, the live and earth are cross-connected at each end of the ring, and the R1+R2 measurement will generally be the same at each point on the ring, unless a fault is present. This also therefore helps identify points on a ring where a spur has been connected.
Does R1 R2 confirm polarity?
The R1+R2 method can also be used to check the polarity of each circuit. When testing R1+R2 at each point it is also necessary to operate the switch in order to confirm an open circuit condition when the switch is in the off position, thereby confirming polarity.
What is the R1 R2 of an installation?
For each outlet on a circuit, the resistance of both the live and earth conductors together (R1+R2) is measured back to the source. It also sometimes identifies socket outlets where a high resistance has built up in the socket itself, for example where a bad connection has blackened or damaged a terminal.
What is an acceptable R1 R2 reading?
The R1 + R2 reading when the dimmer is bypassed, is a reasonable 1.7 ohms, which is protected by a 6A Type B circuit breaker. If your client intends to continue to use the dimmer switch, it may be acceptable to fit a suitably rated RCD to provide automatic disconnection.
