How Can I Test A Ground Wire?

[thaibeachlovers]

There is a groundwire in the kitchen of the house I'm living in now. Goes out through the wall and into the ground outside ( concreted over ). However, I have no idea if it actually works, or just goes 6 inches into the ground.

Advice as to how to check if it's actually viable please.

Please, no very expensive meters though. Can't afford it.

[transam]

I did a ''rough'' test.

Light fitting, one wire in the live and one to earth, bulb will light if earthed BUT may not carry enough ground for high energy stuff, need proper meter.

[Jdietz]

http://www.es.co.th/detail.asp?Prod=06102878

Here's a proper meter for insulation and earth bonding test. Lightbulb test mentioned above is at least an indication you have some grounding.

If you can't afford it, pay someone to do it for you.

[thaibeachlovers]

http://www.es.co.th/...p?Prod=06102878

Here's a proper meter for insulation and earth bonding test. Lightbulb test mentioned above is at least an indication you have some grounding.

If you can't afford it, pay someone to do it for you.

17,000 bht. Guess I won't be buying that then. I'll try the lightbulb.

Guess it'll be safer to just buy a couple of earth rods at 100 bht each and put them in myself. I already have the wire, left over from the last house.

Thanks for the replies.

[transam]

http://www.es.co.th/...p?Prod=06102878

Here's a proper meter for insulation and earth bonding test. Lightbulb test mentioned above is at least an indication you have some grounding.

If you can't afford it, pay someone to do it for you.

17,000 bht. Guess I won't be buying that then. I'll try the lightbulb.

Guess it'll be safer to just buy a couple of earth rods at 100 bht each and put them in myself. I already have the wire, left over from the last house.

Thanks for the replies.

Best bet. Two meter rod.

[thaibeachlovers]

http://www.es.co.th/...p?Prod=06102878

Here's a proper meter for insulation and earth bonding test. Lightbulb test mentioned above is at least an indication you have some grounding.

If you can't afford it, pay someone to do it for you.

17,000 bht. Guess I won't be buying that then. I'll try the lightbulb.

Guess it'll be safer to just buy a couple of earth rods at 100 bht each and put them in myself. I already have the wire, left over from the last house.

Thanks for the replies.

Best bet. Two meter rod.

Agreed, but have you tried getting one of those anywhere other than a Home Pro or equivalent?

Best I can do is two one meter rods wired together. two meters apart, as per Crossy's advice. At least they're the proper thing, copper coated steel, with a built in bolt and nut.

[lopburi3]

Everyone should have a simple (2-300 baht at Lotus) multi meter and that can be used to make a fairly accurate check - measure voltage from hot to neutral and then hot to ground. The closer they are the better the ground. Should be very close to the same reading.

[ExpatOilWorker]

You need something like this and a good grounding should be less than 4 ohms.

[IMA_FARANG]

There is a meter known as a Megger (company trademark name) which measures grounding quality directly.

I believe the efficency of a ground is measured in what is known as Admiitance which is the reciprocal (inverse) of resistance. If I recall correctly Admittance is measured in units called Mho, or the reverse of Ohm, which is what resistance is measured in. You see, don't you, that the word Mho is the word Ohm reversed?

Meggers are expensive and such a test is kind of a specialised test done by such as an installation team setting up the wiring and grounding system for something like a communications system.

The higher the reading in Mhos, the better the ground system is.

But, frankly, where you would find such a test, the Megger to run it, and the people who know how to run it correctly in Thailand I have no idea. For that reason, I doubt there is a chance you can get one down anywhere in Thailand...and even if you could it would be expensive.

For a large system, the building's ground system when installed must be measured, and the reading in Mhos must meet the design specifications for that system. The reading is recorded. On a periodic basis, the electricians come around and verify that reading...if it changes it may mean there is a pfoblem with the central ground for the building...and a maintainence check needs to be done on the system ground and connections.

[InterestedObserver]

There is a meter known as a Megger (company trademark name) which measures grounding quality directly.

I believe the efficency of a ground is measured in what is known as Admiitance which is the reciprocal (inverse) of resistance. If I recall correctly Admittance is measured in units called Mho, or the reverse of Ohm, which is what resistance is measured in. You see, don't you, that the word Mho is the word Ohm reversed?

Meggers are expensive and such a test is kind of a specialised test done by such as an installation team setting up the wiring and grounding system for something like a communications system.

The higher the reading in Mhos, the better the ground system is.

But, frankly, where you would find such a test, the Megger to run it, and the people who know how to run it correctly in Thailand I have no idea. For that reason, I doubt there is a chance you can get one down anywhere in Thailand...and even if you could it would be expensive.

For a large system, the building's ground system when installed must be measured, and the reading in Mhos must meet the design specifications for that system. The reading is recorded. On a periodic basis, the electricians come around and verify that reading...if it changes it may mean there is a pfoblem with the central ground for the building...and a maintainence check needs to be done on the system ground and connections.

Earthing (Ground) resistance is measured in ohms, usually with a 3-point Ground Resistance Tester. Admittance and mhos are electrical terms, used frequently with protective relays in power systems, but I have never seen them used in relation to ground resistance.

[Crossy]

The mho went out of use in the 1970s (although the old guys still use it), it's now called the Siemens in honour of the chap who came up with the concept of conductance or admittance (same unit mind 1/ohms). Use to describe very low resistances <.1 ohm.

Since the ground path of a TT system is unlikely to approach anything like that Ohms are just fine.

If you can get below a few 00 Ohms and have an RCD you're good to go.

As to actually testing your spike, a low wattage lamp between the spike and L should light up, the brighter it is the better the ground, do make sure nobody can touch the spike and that it's completely isolated from the rest of the electrical system before testing.

[thaibeachlovers]

Thanks for all the great advice.

Going up to Chiang Mai soon. so I'll pick up a multimeter then.

[electau]

Insulation values are measured in Megohms. Insulation tests are normally carried out at 500VDC using an approved insulation tester (Megger)

Continuity of earthing conductors are measured in ohms.

Max resistance of a main earth is 0.5ohms.

Max resistance from the main earth connection at the electrode to any part of an electrical installation should not be more than 2 ohms in practice.

The minimum depth of an electrode should not be less than 1.2metres.

A multi meter set on the low ohms range will measure continuity.

With a TT (or direct earthing system) RCDs must be used as a protective device.

　

[thaibeachlovers]

Insulation values are measured in Megohms. Insulation tests are normally carried out at 500VDC using an approved insulation tester (Megger)

Continuity of earthing conductors are measured in ohms.

Max resistance of a main earth is 0.5ohms.

Max resistance from the main earth connection at the electrode to any part of an electrical installation should not be more than 2 ohms in practice.

The minimum depth of an electrode should not be less than 1.2metres.

A multi meter set on the low ohms range will measure continuity.

With a TT (or direct earthing system) RCDs must be used as a protective device.

　

Thanks.