electau

Locate the circuit that is tripping the RCD. You have an earth fault caused by water in a fitting. Leave this circuit off and allow fittings to dry out.

An RCD will trip on earth fault between 50% and 100% of rated current in mA.

If the circuit still trips you will have to use an 500V insulation tester and split the circuit until the fault is found. Insulation between L and E. and N to E. You will have to disconect the circuit to do this. You may have to obtain the services of an electrician to do this test.

Check to see if there are any fittings still under water first.

Those connectors are available to take wire sizes up to 6 x 4 sqmm (Wago 223-413). Made in Germany.

You could use standard BP ( Clipsal) single screw and 2 screw insulated tunnel type connectors if above not available in Thailand. Available in quantities of 100 and 50.

The 3M ( wirenut) is an insulated US type connector. Available in red , blue and yellow .

Single core PVC insulated PVC sheathed is another way of describing the cable you require.

khaan,

One question, are the socket outlets 3 pin or 2 pin? If 3 pin are they earthed? Is the airconditioner earthed?

Jackson had serious mental health problems and should have been treated in an institution. He was by no means a normal person. Justifies euthanasia.

His doctor did him a favour. He looked like something out of a horror film.

It is very important which earthing system is used within an electrical installation.

TT. No link between the main neutral and the main earth. RCDs/RCBOs must be used to obtain tripping times under earth fault conditions. The fault path is through the PE conductor to the earth bar and the main earth conductor and main earth electrode. The resistance is far too high for an MCB to operate under earth fault conditions.

TN-C-S or MEN system. The neutral is bonded to the earthing system. RCDs are installed as additional protection and where required by standards (AS/IEC). eg socket outlets. the fault path here is through the PE conductor to the earth bar and then through the main neutral to the transformer. Negligable current flows in the main earth conductor and this can be disregarded. The impedance off the earthing system and the L and N conductors from the transformer must be such so as to operate an MCB in less than 0.4secs. If this can not be achieved an RCD or RCBO must be used.

If the minimum sizes of conductors and protective device ratings are complied with the above will be achieved within an electrical installation.

TN-S. The only difference here from the MEN system is that an earth conductor is run directly to the transformer earth from the earth bar of the main switchboard and this is the only bond to the main earth. The main earth is the earthing of the neutral conductor. May be used where an on site transformer supplies the main switch board of a large building ot a multi tenanted building. S= separate earth

TN-C This refers to the common neutral and earthing conductor from the transformer to the main switchboard neutral link of the electrical installation.

Earthing requirements for the earthing of a transformer neutral and distribution system MEN connections are far more onerous and are generally covered by regulations of the supply authority.

Testing. Testing must be carried out before connection to supply. Earthing. Insulation, Polarity tests etc.

RCDs should be tested at least every 3months by the use of the test button on the unit. this tests the functional operation of the unit. It does not test the continuity of the PE conductor.

The apartment block may have its own transformer. Yes, the earthing arrangements would have to be verified.

One note on the 20 ohms earth contact resistance if it can be attained it would still not be low enough to trip an overcurrent device (MCB) on an earth fault in less than 0.4 seconds. However using RCDs the tripping time would be reduced to less than 0.2/0.3 seconds.

An RCD will provide superior "earth fault current" sensing and response time, compared to a conventional MCB. Hence a circuit protected by an RCD device during a fault provides suitable touch voltage protection.

Earth bonding ( equipotential bonding) reduces the effect of touch voltage also.

If you are in Australia you can contact DIAC general enquiries on 131881. That is where I found out the original information on address change and passport renewal (Thai passport).

Before the days of the electronic visa you could carry the old passport with the current visa label if it was still valid eg, permanent 100 or a 155 RRV.

Not so now. I did ask if it could be done at an Australian Port of Entry but the answer was negative, the Form 929 must be submitted. It took me about 5 minutes on the phone to obtain the information.

It is a point that could be easily overlooked.

In reply to #18.

This is why RCDs are used on TT systems the earth return path through the soil is far too high for an overcurrent protective device (MCB)to operate in less than 0.4secs. 50VAC = 30mA x 1666 ohms. An RCD must operate between 50% and 100% of its rated tripping current in mA.

(Based on a 13sqmm copper clad steel electrode as a main earth at a depth of 1.2/1.8metres). Soil resistance is not a constant value.

Persons can be and are electrocuted from the following, contact with a live conductor and earth and a live conductor in contact with water, eg in a flood situation. contact with the water can be at the metering point. Not all electrical installations have RCDs fitted. Also fallen power lines, they should always be regarded as live. If they are in water you may not see them.

In Qld Australia the floods in Jan 2011 caused widespread damage to property and in areas affected the HV distribution was deenergised for safety. No building was reconected until a full electrical safety inspection had been carried out.

If you are going to Australia make sure that DIAC has the applicants address. Here is the website for a 929 form. All visas are now electronically connected to the DIAC data base, no more paper visa labels in a passport. They will give you a printout of the visa number and expiry date.

http://www.immi.gov.au/search/search.cgi?scope=www.immi.gov.au&query=929&collection=immi-all-sites&form=simple&num_ranks=10&Search=Go

Circuits should be wired in a loop in loop out method, That is the circuit from the MCB at the switch board to either the switch or the light fitting in the case of lighting circuits and for power circuits from socket outlet to socket outlet.

Junction or cable termination boxes need only to be used where required. Eg additions or alterations to circuit wiring.

The so called ring circuit should not be used.

Flat 2 core and earth TPS cable should be used. This will give you an earth at all points of utilisation. Cable can be run as unenclosed in free air in ceiling spaces and cavity walls and on the surface of walls enclosed in PVC duct.

Terminals from junction boxes can be screw type tunnel,( BP/Clipsal) or insulation displacement type (Waco) or the US screw on wire lock type (3M).

Twisted and taped joints must never be used.

All final subcircuits must have an overcurrent protective device.(MCB or RCBO) the size in amps must not exceed the current rating of the cable. The maximum demand of the circuit must not exceed the rating of the cable.

Yes install a RCBO and make sure that the shower heater is earthed. Is there an earth conductor to your distribution board from the building main switch board?

What is the rating of your shower heater and the cable size in sqmm?

Yes, an overheating terminal in an MCB can cause the device to trip.

In reply to post #5 by southpeel.

One should look at workplace health and safety as type of industry based. Eg.

Construction

Transport eg road transport

Mining

Petroleum ( oil and gas)

Manufacturing

Food

Agriculture and Fishing.

Contracting Industries.

Electrical, Mechanical services, Building contractors etc.

WH and S covers training for all involved , their legal responsibilities and duty of care.

It covers employees, supervisors, management, contractors and their employees.

How many businesses in Thai land carry public risk insurance?

They are 3 pole contactors switching possibly remote loads such as lighting,. One should look for a time switch or a remote switch controlling them.

The loads seem to be single phase from each contactor. Is the installation a residential or commercial one?

It would be advisable not to use the MEN system unless it is used on the LV disribution system in your area. You should check with the PEA/MEA for their policy.

The TT system with RCDs is the safer option. That is NO link between the main neutral and the earthing system.

If a Thai passport is renewed and it has a current visa it must be transferred to the new Thai passport as the visas are now electronic and on the DIAC data base linked to the passport number. The form number is 929 and is downloadable from the DIAC website.

For further information call 131881 General enquiries in Australia or contact DIAC at the Australian Embassy.

I checked this fact by calling the above number to enquire because my wife has renewed her Thai passpost last year and we intend to travel at the end of 2011.

It can be done by personal visit to a DIAC office or by mail, with 1 certified copies of the personal particulars page of each passport. The instruction form is 929i.

Does the old Thai passport have a current visa affixed? If so you will probably be able to show both passports. What about when you enter the UK? Will they accept both passports? A phone call to the British Embassy might be worth while.

Just for interest Australia has electronic visas which are on the DIAC data base. If a new eg Thai passport is issued the visa must be transfered to the new passport. DIAC will not accept the old passport.

The DIAC form number 929 and instructions 929i are downloadable from the DIAC website.

If you intend to install any electrical equipment eg pool filter, lighting etc make sure the any steel work in the pool (rebar) is equipotentially bonded to your main earth and that all electrical equipment is protected by 10mA RCDs and is earthed. Any in pool lighting should be SELV (safety electrical low voltage) ie less than 25VAC.

The concept of safety is unknown to most Thais.

In Western countries one has a legal duty of care to onself and to others. This is not so in Thailand. Legislation on safety in the workplace is generally not applied if it exists.

In Western countries safety breaches can and are enforced by the legal system in a court of law.

Qantas has less than 20% of the international airline market in Australia and has to compete with the likes of Singapore, Thai and Malaysian Airlines which are goverment owned /subsidised.

Qantas has 65% of the domestic market and this is the part that makes a profit, with its low cost airline Jetstar.

The one feature of Qantas is its safety record, it has not lost one aircraft (except in WW2)

It has a very high standard operations and maintainance and is a world leader in crew training.

Qantas is now a publicly owned company and the majority shareholders are institutional ones not individual share holders.

It might well be pointed out that the CEO is Irish not Australian.

The ongoing dispute is currently before the Fair Work Tribunal.

How ever Qantas has to restructure its work force to compete internationally.

It does not have to go offshore to do this.

The Australian government could buy the international arm of the Airline as it is an essential service as far as Australia is concerned.

Installing a 30mA RCD upstream of a 10mA RCD is perfectly allowable as the 10mA RCD will trip in less than 0.04seconds and the 30mA will trip in less than 0.2/0.3 seconds.

Max standing leakage current should nor exceed 30% of the rated unit. In practice this should be 1mA or less. Remember standing leakage current is additive.

If your electrical installation is TT or direct earthing RCDs must protect all final subcircuits, ie. permanently connected electrical equipment.

An RCBO is permitted to be used as a main switch. In the event of an earth fault it will disconnect the whole installation.

Circuit distribution can be (1) RCBO (main switch) MCBs (final subcircuits). or.(2) MCB (main switch) one or more RCDs or RCBOs,then MCBs ( final subcircuits) from the load side of the RCDs. Depending on the number of final subcircuits you may require more than one RCD.

DIN rail mounted MCBs and RCDs should be utilised if possible as they fit most load centre enclosures (distribution boards).

The earth resistance of a 13mm single copper clad earth electrode at a depth of 1.2/1.8 metres in average moist soil in an areas exposed to the weather is generally about 70 to 100ohms. This is the contact resistance with the soil.

However, this value is a minimum practical value but may rise to over 500ohms. This is why RCDs must be utilised on electrical installations that use the TT or direct earthing system.

Earthing of HV is normally 30ohms at the transformer and for LV earthing 10 ohms. Earthing for these values requires more complex (and expensive) earthing proceedures which are not required for normal electrical installations under AS or IEC requirements.

What does this EIT code state on the following?

Tripping time of an over current protective device on an earth fault eg MCB.

Voltage drop within an electrical installation.

Earthing. The minimum size of a main earth ME conductor. Equipotential bonding.

The minimum size of an PE conductor. Earthing of conductive metal work that may become energised under earth fault conditions.

The installation of RCDs on final subcircuits. tripping times for an RCD.

The MEN (TN-C-S) and TT earthing systems

Testing and verification of electrical installations.

If the document is in Thai there must be an Edition translated into English otherwise you cannot interpret it.

Standards can conflict in many cases especially if one tries to use both the NEMA and IEC.

With reference to post by dhrobertson.The basis of any electrical installation standard for buildings should be based on IEC 60364, thus eg, AS3000/2007 can be used for guidance purposes. As Thailand uses the nominal 220/230- 380/400 50Hz system

The LV distribution system earthing is covered by other legislation as required and should be enforced by the PEA/MEA.

Earthing requirements for electrical installations are covered by IEC 60364, AS3000. or BS7671.

If the TT system is used RCDs must be installed on all final subcircuits. The main earth electrode need only to be 13mm copper clad, 1.2/1.8 metres into the ground. MEN link at the main switchboard.

Those figures that you have given along with earthing requirements appear to be NEMA requirements.

There is a demarcation line between the definition of "electrical installation" and the service conductors, protective devices and distribution system of the PEA/MEA.

One requires a standard that can hold up from a legal perspective in a court of law. AS and BS standards meet this requirement in the own respective countries.

A note also that to use these standards one must be able to interpret them within the meaning of the standard used. And that requires one to have formal qualifications.

Electrical safety is the priority here, that is why standards are used to minimise the risk of fire and shock within an electrical installation.

This EIT code, how can it be used if it is not generally available to the electrical contracting industry, the electrical industry and electricians so they know what is required of them?