Protection Against Voltage Disturbances

[John-]

Quick Q.

Am doing 18th edition at the mo. Reviewing chapter 44 (from p95).

Calculated Risk levels for the the use of SPDs.

When you have calculated the risk level (CRL), what do you compare it against to know whether the risk is accelerate or not? Worked examples are in the regs book with results but they don't say what to compare the results against?

Also... Page 119 Table A444.2 two columns with the same titles (Minimum Separation between Power and Signal Cables (m)), both have different figures? Am i missing something there?

Thanks

John

 

[John-]

ok, feeling silly now. 1000 seems to be the benchmark - lower than needs SPD higher than 1000 does not. Sorry!

 

[buzzlightyear]

Table A444.2 and 2 notes are new (minimum separation between power and signal cables)

 

[buzzlightyear]

where cable voltage is at 240 v the min separation between the power and the signal cable .

 

[Pete999]

ok, feeling silly now. 1000 seems to be the benchmark - lower than needs SPD higher than 1000 does not. Sorry!

Saw rite Mate SPDs make everyone go a bit loopy, no bad spelling icons please it was an attempt at street humor