Electrician in Johannesburg Earth Leakage Repairs and Earth Leakage Tripping Solutions
Earth leakage problems – earth leakage tripping for no apparent reason? We are the preferred choice in all emergency earth leakage tripping repairs and solutions. Call Electrician in Johannesburg now and get your problem solved in no time.
What causes earth leakage tripping?
An Earth Leakage Circuit Breaker (ELCB) is a safety device used in electrical installations with high earth impedance (resistance) to prevent shock. It detects small stray voltages on the metal enclosures of electrical equipment, and interrupts the circuit if a dangerous voltage is detected. It measure if the current coming in is equal to the current coming out of the circuit. If not then it will assume that a small part of the current does not flow out the other wire but rather "leaks" to the ground/earth.
An Earth leakage circuit breaker silently monitors the electrical condition of your appliances and the Earth connection of your house. If anything goes wrong with them it will instantly switch off the mains and stop any further associated loss.
Earth Leakage Tripping is often traced to faulty stove plates, servant plugging in old hot plates and faulty Irons
The main purpose of earth leakage breakers is to prevent injury to humans and animals due to electric shock.
We repair and install both voltage-operated earth leakage circuit breakers and current- sensing protection.
Advantages of Earth Leakage Circuit Breakers
Earth Leakage Circuit Breakers (ELCB) have one advantage over normal Residual Current Circuit Breakers (RCDs): we recommend them because they are less sensitive to fault conditions, and therefore have fewer nuisance trips. By electrically separating cable armour from the cable circuit protective conductor, an earth leakage circuit breaker can be arranged to protect against cable damage only, and not trip on faults in downline installations.
Earth leakage disadvantage 1: They do not detect faults that don't pass current through the Circuit protective conductor (CPC) – A name used for the protective earth wiring of all metal parts of a building to the earth rod
Earth leakage disadvantage 2: They do not allow a single building system to be easily split into multiple sections with independent fault protection.
Earth leakage disadvantage 3: They may be tripped by external voltages from something connected to the earthing system such as metal pipes or a combined neutral and earth.
Earth leakage disadvantage 4: As with RCDs, electrically leaky appliances such as some geysers, washing machines and cookers may cause the ELCB to trip.
Earth leakage disadvantage 5: ELCBs introduce additional resistance and an additional point of failure into the earthing system.
Nuisance electricity tripping
While voltage and current on the earth line is usually fault current from a live wire, this is not always the case, thus there are situations in which an earth leakage circuit breaker can nuisance trip.
Earth Leakage Nuisance Tripping 1:
When an installation has two connections to earth, a nearby high current lightning strike will cause a voltage gradient in the soil, presenting the earth leakage circuit breaker sense coil with enough voltage to cause it to trip.
Earth Leakage Nuisance Tipping 2:
If the installation's earth rod is placed close to the earth rod of a neighbouring building, a high earth leakage current in the other building can raise the local ground potential and cause a voltage difference across the two earths, again tripping the earth leakage circuit breaker. Close earth rods are unsuitable for earth leakage circuit breaker use for this reason, but in real life such installations are sometimes encountered.
Earth Leakage Nuisance Tripping 3:
Due to accumulated or burden currents caused by items with lowered insulation resistance. This may occur due to old equipment.
Earth Leakage Nuisance Tripping 4:
Due to equipment with heating elements, or even wiring in places where prolonged damp and rain conditions can cause the insulation resistance to lower due to moisture tracking. If there is a 30 mA protective device in use and there is a 10mA burden from various sources then the unit will trip at 20 mA. The individual items may each be electrically safe but a large number of small burden currents accumulates and reduces the tripping level.
Earth Leakage Nuisance Tripping 5:
Tubular heating elements are filled with a very fine powder that can absorb moisture if the element has not been used for some time. For example if a clothes drier has not been used for a year or a water boiler used for coffee etc. has been in storage. This type of problem can be seen even with brand new equipment.
Both RCDs and earth leakage circuit breakers are prone to nuisance trips from normal harmless earth leakage to some degree. On one hand earth leakage circuit breakers are on average older, and hence tend to have less well developed filtering against nuisance trips, and on the other hand earth leakage circuit breakers are inherently immune to some of the causes of false trips RCDs suffer, and are generally less sensitive than RCDs. In practice RCD nuisance trips are much more common.
Failure to respond
With any mechanical device, failures occur, and earth leakage circuit breakers should ideally be tested periodically to ensure they still work.
If either of the earth wires become disconnected from the earth leakage circuit breaker it will no longer trip and the installation will often no longer be properly earthed.