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Member postings for martin kilroy 1

Here is a list of all the postings martin kilroy 1 has made in our forums. Click on a thread name to jump to the thread.

Thread: Insulation tester - some guidance please
20/12/2018 13:56:23

Measuring insulation resistance with high DC (relative to normal operating voltage) is pointless if all you are trying to ascertain is whether the equipment is safe to energize. Take a typical domestic 240V installation with MCB overcurrent protection and 30mA RCD earth fault protection. To operate the MCB the phase to neutral or earth insulation would need to have an resistance of just a few ohms and to operate the RCD an resistance of a few Kohms. Both these values are easily detectable with a multimeter and a deciscon on the safety of energizing can be made. Once the system is energized the safety of the system and its insulation is down to its design, maintenance and operation.

However if you are trying to ascertain the condition of the insulation then its resistance (measured with high DC voltage) may be helpful but interpreting the results will be difficult.

At higher system voltages (above 11kV) there is evidence that high DC test voltages cause damage to plastic insulated cables.

My view is use a decent multimeter to check your insulation.

Thread: Telephone Scam ??
02/12/2016 13:35:26

It's great having time on your hands, I had the "we.re from Windows" lot on the phone for an hour before they got angry worked out I knew exactly what they were trying to do. Great fun

Thread: cuttingthreads
04/05/2015 17:35:07

http://www.motalia.com/Html/Charts/thread_charts.html

Thread: digital calipers
13/01/2015 19:09:56
Posted by TSH on 13/01/2015 18:14:30:

I have a cheapo digital caliper (from Lidl IIRC) which in recent weeks would, without warning, change reading by 5.08mm (always this amount). This has not happened since renewing the battery.

Trevor

Two tenths of an inch

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