How to use a megger!!!

[Gees]

Does this seem right ( especially turning the handle at 160 turns A second )

Use a Megger to test the insulation on a grounded wire or between the conductors on a circuit board. Testing the grounding system for hospitals, business parks or any other kind of facility, can help prevent electrical surges. As with any type of current, lightning storms find the least path of resistance, and always hit the ground. Learning to use a Megger can reduce the likelihood of electrical damage to a facility.


Step 1..Clamp a pair of ground testers on the grounding rod in the facility you wish to test. This is sometimes called the grounding cable. The facilities manager, architectural engineer or electrician, can tell you where the grounding rod is located. Wind the handle of the generator on the Megger at about 160 turns per second. One clamp will measure for the voltage, and the other clamp will measure the current. The Megger indicator will show the ground loop resistance at the grounding rod in the facility. Usually, a technician will multiply the number of grounding rods or poles by the reading in watts for the total loop resistance.

Step 2.. Test a device, motor or circuit board between the circuit and the earth. Hook one terminal from the Megger to your circuit board and the other to a stake in the ground. Make sure you unplug the power on the circuit or motor that you are testing. Wind the generator with the handle on the Megger at about 160 turns per second. Note the reading on the indicator of the Megger. This is your measurement for insulation in the circuit via the earth test. Your Megger calculates the measurement for you.

Step 3..Take an infinity reading. Pair each wire on the circuit board. Measure each wire to the other wire on the circuit board, and then measure each wire to the metal conduit. Wind the generator with the handle on the Megger at about 160 turns per second. The reading will appear on the indicator screen of the Megger.

Step 4...Take a reading for the bus on a PCB circuit board. Follow the bus lines to their bus tangs (the ends). Take a measurement for each bus by connecting the terminals from the Megger to the bus tangs, and then wind up the generator at about 160 turns per second. Lastly, measure from the Megger to the case of the device you are testing.

I think its from the States ???
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[holmslaw]

..

 

[Spark123]

What type of Megger? (Megger is a brand name, it used to be called AVO). Megger is often used as slang for an Insulation Resistance tester but step 1 doesn't appear to be using that, unless it is meaning on low ohms range?

 

[ban-all-sheds]

Turn the handle at 9600rpm?

That would be impressive - if the handle was about 100mm long your hand would be travelling at about 100m/s.

I do wish I knew what this meant: "a technician will multiply the number of grounding rods or poles by the reading in watts for the total loop resistance"

http://www.ehow.com/how_4601458_use-a-megger.html

http://www.ehow.co.uk/how_4601458_use-a-megger.html

Cretins.

 

[ericmark]

As you rightly point out 9600rpm for hand cranking seem a tad out.

It is not so bad when it is completely daft we just laugh but it is so easy for people to read instructions and try to follow with some dangerous results.
Seems original starting instructions for Ford Model T were like that and if followed to letter one would be run over.

In the days where we used common sense Ford was not sued but same today and it would be completely different outcome where drivers if their accelerator peddle gets stuck in floor mat can't even switch ignition off!

It seems to be referring to an earth rod testing kit and I have to admit even after using one for 6 months solid I could not remember now exactly how it is used but all the models I have used have 3 or 4 connections and the readings were in ohms not watts.

I know we can read ohms by measuring volts and amps but the description is more like the connections for a data logger than megger at this point.

I would guess some one has been told to translate and they were not technical translators. One still wonders what the device really was though. I remember a kid on the Falklands being asked to describe a semi-detached house. And he said if you fly over one in a helicopter it's not quite put together. Considering he had never seen one not really a bad answer. Really it is the name we use which is wrong, why don't we call them double houses? I am sure somewhere in the world that is what they are called.

I keep meaning to get the translation for notices in caravans Fig 721 in Welsh could use dictionary but likely I would produce something like you have posted.

 

[theedam]

check out http://www.theedamelectrics.com - good site for info like this.

 

[ericmark]

Thank you BAS for link seems to come under heading of "Gobbledygook"

 

[ericmark]

check out http://www.theedamelectrics.com - good site for info like this.

This is another good example of "Gobbledygook" the statement "Can only be issued by an Approved Contractor" for Electrical Installation Certificates is wrong these are produced by person doing the work it is the "Completion Certificate" that needs either someone registered under Part P or the LABC to issue.

As it is at the moment the person completing the Electrical Installation Certificate has to sign that he has exercised reasonable skill and to best of his knowledge and belief it is in accordance with BS 7671:2008 there is no qualification required. Most people would expect at least a C&G 2382 and one would hope a C&G 2391 but there is no requirement for these.

 

[Stoday]

Before using the megger, you have to connect it. Priya Hariharan tells you how to do so: connect one test lead to a conductor and the other to an insulator.

http://www.ehow.com/how_5718108_connect-megger.html