Suruhanjaya Tenaga - Prohibition on The Use Of Voltage Operand Earth Leakage Circuit Breaker (ELCB): "Prohibition on The Use Of Voltage Operand Earth Leakage Circuit Breaker (ELCB) Print E-mail
Tuesday, 13 March 2007
Earth Leakage Circuit Breaker is a kind of safety equipment which protect consumer from electric shock if leakage current is occurred to consumer equipment. This gadget will cut off the electric supply instantaneously when current leakage is detected. There are two types of ELCB, they are Voltan Operand and Current Operand.
Prohibition On The Use Of Voltage Operand Earth Leakage Circuit Breaker (ELCB)
Earth Leakage Circuit Breaker is a kind of safety equipment which protect consumer from electric shock if leakage current is occurred to consumer equipment. This gadget will cut off the electric supply instantaneously when current leakage is detected. There are two types of ELCB which are Voltan Operand and Current Operand. However, Voltage operand ELCB is less effective compared with Current Operand ELCB.
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Voltage Operand ELCB
Regarding to investigated electric accident cases, especially those involved domestic coupling, the lack of ELCB function become the major cause which contribute to death cases. By such, the usage of voltage operand ELCB PLBK must be stopped immediately and only current operand ELCB type can be used. current operand ELCB type also known as Residual Current Device (RCD). Besides, there are also other names for this RCD-like functions.
Any replacement or installation of RCD must be done by electric contractor who are registered with Energy Commision with the RCD which possess SIRIM label only. Please ensure that the electric contractor shows his certificate of registration before starting the work.
untitledWhen leakage current occured, this current will grounded through the wire bonding. Wire bonding is ended in earth chamber. RCD with sensitivity rate of 100mA usually installed in distribution box. However, to utilise hand operand portable equipment, additional RCD of 30 mA sensitivity rate must be installed first into power plug. supply of Electrical equipment which are used at the place toy or watery area such as bathroom, swimming-pool and fountain pond, RCD’s sensitivity rate that must be used is 10mA. This rate is accordance with the requirement of Electricity Regulations 1994. This RCD should also be tested at least once in a month to make sure it function properly. Briefly, RCD's rate is as follows;
Type of Equipment
RCD Maximum Rate
RCD needs to be fixed in distribution chamber either single phase or threephase assembly. Connection should be done for any final circuit, either individually or in group.
100mA
Equipment, apparatus or portable appliance such as washing machine, refrigerator, electric hollow punch, must have the second RCD. Therefore,outlet socket need to be fixed with RCD and the installation could be done in distribution chamber. However RCD portable type also could be recycled.
30mA
Assembly in place of public recreation areas which have children toys such as kiddy ride, machine video etc. need to be fixed with RCD.
10mA
Electrical equipment like electric water heater fitted at the place where the floor will get wet or if wall or low electric resistive siege like bathroom should have second RCD.
10mA
However, this RCD is undefended from high voltage caused by lightning. Another device are required to get protection from lightning. Users also should take safety courses in handling electric wiring issue.
How Earth Protection System Function?
Each final circuit will be equipped with three terminals which are connected to equipment, life, neutral and earth teminal. Earth conductor is conncted from this earth terminal to earth chamber. When current leakage occurred to the equipment, this current will flow to earth mass through earth conductor. This current leakage is detectable by RCD. RCD will disconnect the supply instantly to avoid any danger to human. Hence, earth conductor from this earth chamber must attached to outlet socket and to all electric equipment which have exposed metal part.
What Is Earth Chamber ?
kotakEarth chamber is where a ground electrode (about 1 metre long) embedded into earth. All ground wire (earth conductor) are connected to it. Connection to this earth is to restrict the voltage/current caused by the damage to the safe level until the Miniature Circuit Breaker fuse is burnt or RCD is jerked. This protection could not avoid someone from electric shock, but it time and current features are able to assure that the shock is not killing. It is really required to have very low earth wire resistance which may facilitate the current flowing to ground when damage is detected.
Damaged earth protection system or electrical equipments are not connected to earth wire will avoid the RCD from jerking during the damage of current. Ensure that earth chamber at your house is always closed and not exposed. Please ensure that it is not cemented especially during the house renovation etc..
Do all the electrical equipment should be connected to earth wire?
gambarElectrical equipment which is connected to earth wire is also known as Class 1 equipment. All electrical equipment which have metallic body are required to be joined to earth wire and use three pin plug. Electrical equipment which not have to be connected to earth wire are called as Class 2 equipment. Equipment without electric metallic body don’t have to make wire connection to earth and it can use two pin plug. However, all the equipment is fabricated so that it have two insulator systems and therefore, that possibility to gain electric shock is avoidable. It is basic things in electrical safety that each damage that happen does not cause malignancy. It is very important for each equipment electric meet the requirements of prescribed safety standard to avoid danger situation. Each approved equipment by the Energy Commission are tested to meet the need of standards safeguard that has been fixed.
What Is Distribution Chamber ?
agihIt is also known as fuse-box and it is located between TNB's electricity metre and all electric circuits inside the house. It place Main Switch, ELCB/RCD, Miniature Circuit Breaker (MCB)/ fuse, life, neutral and earth terminal. Nowadays wiring system does no longer using fuse and it is replaced with Miniature Circuit Breaker-MCB which function approximately like a fuse. Besides, there is also another safety equipment which is called as Earth Leakage Citcuit Breaker (ELCB) or also known as Residual Current Device (RCD).
What Is Miniature Circuit Breaker ?
plkMCB’s function is like fuse where it protect the electric circuit wiring system from supercurrent which triggered by overload or short-circuit. If the current rate exceed the MCB rate, then the MCB will jerked and must be reset to so that the circuit could be linked again. This is one of the MCB’s virtue over fuse because it is able to be used for many times
What is the difference between MCB and ELCB ?
MCB provide protection from current / overload and short-circuit. It is more in protecting electrical equipment and wiring system itself. In the other hand, ELCB give protection to mankind from the electric shock resulted from current leakage
What is Earth Leakage Circuit Breakers - ELCBs ?
It has been categorised into two types, voltage operand ELCB and current operand ELCB. Voltage operand ELCB was first introduced about 60 years ago while the current operand ELCB was started approximately 40 years ago (introduced in 50’s).
How Voltan Operand Earth Leakage Circuit Breaker functions ?
Current passes the ELCB. ELCB contains relay loop which it being connected to the metallic load body (as example the body of kettle) at one end and it is connected to ground wire at the other end. If the voltage of the load body is rise which could cause the difference between earth and load body voltage, danger electric shock will occured. This voltage difference produce an electric current from the load metallic body passes the relay loop and to earth. When voltage on the the load metallic body raised to the danger level which exceed 50Volt, flowing current through relay loop could move the relay contact by disconnecting the supply current to avoid from any danger electric shock.
How Current Operand Earth Leakage Circuit Breaker functions ?
Current passes the ELCB. This current admitted to current transform device (doughnut shaped tool) and on load. Current from the load also admitted again to transform device. In normal state, total current applied to load is equal with total current out of the load. Because of the balance of in and out current, it does not effect the current transform device. If there is any earth current leakage caused by earth damage, then the in and out current will no longer in balance. This imbalance phenomena will generate current and if the current exceeded the prescribed rate, the ELCB will jerked and cut off the supply.
Which is better ?
If there is earth leakage current, voltage operand ELCB will only jerked when the current that passes relay loop is enough to move relay contact to cut off the supply. Otherwise, the leaking current will flow to earth. Level of protection from electric the shock given by voltage operand ELCB is not quite sensitive. Another its disadvantage is it tends to jerked from earth current caused from other assembly. While current operand ELCB will jerked if in and out current is not balanced. Current operand ELCB is more sensitive for earth current leakage.
The utilisation of voltage operand ELCB was abolished in Malaysia since 1994. Referring to Wiring Rules Institute of Electrical Engineers, the utilisation also banned since 1985 (IEE's Rule 15). All voltage operand ELCBs need to be changed to current operand ELCB as soon as possible for safety purpose.
What is Residual Current Device-RCD?
Normally, both stated devices are called as ELCB because they have the same function. However in the utilisation and application of standard safety, current operand ELCB is called as RCD - Residual Current Device to make comparison become easier. It need to be emphasized here that RCD will not be able to save somebody from affected electric shock caused by direct contact. Therefore, people are advised not to repair or open any wiring system or electric equipment. Make sure that this job is done by accredited person from the Energy Commission. RCD is fabricated to prevent electric shock caused by indirect contact such as touching metallic kettle body which is switch on as a result from earth leakage current
What types of RCD?
simbol1simbol2Type of protection given by RCD is divided into two and labelled as following;
* AC's type is used only for protection from alternate earth leakage current
* A type is used only for protection from earth leakage current for pulsating DC and rectified AC
* B type is used only for protection from earth leakage current for pure DC earth fault currents which is restricted to specific use (e.g. rectified three phase suplies).
What Is RCD Rating?
This rating is the limit of earth leakage current where if the leakage current exceeded the rating limit stated then the RCD will jerked and cut off the supply. Regarding to Electricity Regulations 1994, PRCD rating is determined as below;
Rule 36
(1) For assembly in public entertainment place, protection for earth leakage current must be done to any final circuit which supplying the power to any equipment in the mean of providing services to public can be accessed, used or operated by the public by using residual current device which have rated balance not exceeding 10 milliampere current operand;
(2) For assembly at the place where the floor will get wet or if wall or low electric resistive siege, protection for earth leakage current must be done to any final circuit which supplying power to any equipment, either separately, or in group, which have current operand rated balance not exceeding 10 milliampere;
(3) For assembly if equipment, apparatus or equipment hold with the hands used or probably used, protection for earth leakage current must be done to any final circuit, either separately or in group, with residual current device have current operand rated balance not exceeding 30 milliampere of.
(4) For assembly, other than those mentioned in subregulation (1), (2) AND (3), protection for earth leakage current must be done to any final circuit, either individually or in group, with residual current device have current operand rated balance not exceeding 100 milliampere unless ;
(a) on functional reason, it is not practical to make that protection; OR
(b) it would be unsafe or dangerous to make the protection.
Does the RCD can avoid someone from electric shock ?
There are many factors that determine someone is safe from electric shock and one of the factor is the period of shock affected and electric current flow. RCD is designed to jerked to cut off the supply when it achieved the limited rate. It cannot be guaranteed to save someone from electric shock and therefore, other electric protection system in electrical wiring system should also be given more attention. However RCD helps to ensure that the electric shock is a painful experience and not bring to the deaths.
Equipment that give the electric protection in electrical wiring system is ELCB, RCD, fuse in three pin plug and ground wire. RCDs are suitable to protect from electric shock.
Does the RCD need to be tested ?
untitledIn RCD there is a button which is applied to ensure the jerk system is functioning very well. Testing it once in a month is encouraged.
This test is to make sure that the mechanical device inside the RCD does stuck, cling or damaged which can prevent it from cut off the supply if earth leakage current.
What should you do if RCD is jerked ?
If RCD is jerked, two things can be done;
1. If RCD is switched on and RCD still jerking, then there are possibilities that the equipment which being switched on and has damage with continuous earth leakage current. In that situation, switch all electrical equipment off including light and others. Switch the RCD on once again and switch all the equipment one by one until the RCD jerked again. Separate the equipment. If the situation occurs although the equipment are apart, please contact electric wireman who is registered with Energy Commission to fix the damage.
2. If RCD is switch on and it still jerked even after all electrical equipment is switch off, then there are possibilities of continuous imbalance between input current (life) and output (neutral) inside the circuit. Whole wiring system need to be checked. Please contact electric wireman who is registered with Energy Commission to mend stated damage.
How to protect electrical equipment from damage caused from lightning ?
Lightning is a phenomenon where a high electricity is generated in very short period. It can cause the damage of equipment which have electronic component. RCD does not provide protection from high voltage caused by lightning.
Lightning protection system must be installed to block the generated energy from entering the electric wiring system at home.
What are the precautions should be taken of ?
* Metallic electrical equipment must use three pin plugpalam1
* Please do not use electrical equipment with the wet hands.
* Make sure to read handbook that are provided when buying electrical equipment.
* Make sure electrical wiring system is not connected / changed without wireman that approved by the Energy Commission.
* Switch off the unused equipment.
Other names those related
rccb1rccb2Residual Current Circuit Breaker – RCCB. This is mechanical switch and added with PAB. It main function is to protect the consumer from earth leakage current.
rcboResidual Current Breaker With Overcurrent Protection - RCBO. This is Overcurrent Circuit Breaker added with RCD function (MCB +RCCB). It has dual function;
(a) to provide protection from earth fault currents; AND
(b) to provide protection from over currents.
RCBO's disadvantage is if it jerked, it is unknowable whether it caused from overcurrent or earth fault current.
GFI = Ground Fault Interrupt. This term is normally used in North America. It operation is as same as PAB.
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