Paphos Life

lefkes wrote: ↑Fri Jun 01, 2018 4:22 pm I had the same problem, every time there was a storm near by the 40 amp r c d would trip off ,replaced it with a 60 amp r c d .no more problem.
Job done by Cypriot neighbour .
Lefkes.

lefkes wrote: ↑Sun Jun 03, 2018 12:42 pm

lefkes wrote: ↑Fri Jun 01, 2018 4:22 pm I had the same problem, every time there was a storm near by the 40 amp r c d would trip off ,replaced it with a 60 amp r c d .no more problem.
Job done by Cypriot neighbour .
Lefkes.

The replacement r c d unit fitted is a Gardy 60 amp with a cut out protection of 500 ma. this replaced a 40 amp unit that was damaged in a lighting storm early last year. It now seems from information on this site this too needs to be replaced ?.
Lefkes.

bmwx5 wrote: ↑Sun Jun 03, 2018 10:48 am The differences between an MCB and RCD .

A RCD (Residual Current Device) is a type of circuit breaker ( RCCB ) that reacts to imbalances between the live and neutral supply lines by cutting off the supply extremely quickly. A RCD is designed to near-instantly ‘break’ if the difference between live and neutral is 30mA (or 0.03 amps).

In general, the only reason they’ll be an imbalance between line and neutral is if current is leaking to earth somehow. That somehow is likely to be via an electrical fault connecting the live wire to a significant conductor like the water pipes . But it could also be a current flowing through the hands of someone who has just touched a live wire, or through parts of their body and out through their feet to earth .

Nuisance tripping of RCCB:
Sudden changes in electrical load can cause a small, brief current flow to earth, especially in old appliances.
RCDs are very sensitive and operate very quickly; they may well trip when the motor of an old freezer switches off.
Some equipment is notoriously `leaky’, that is, they generate a small, constant current flow to earth. Some types of computer equipment, and large television sets, touch type on-off table lamps are widely reported to cause problems.
•RCD will not protect against a socket outlet being wired with its live and neutral terminals the wrong way round.
•RCD will not protect against the overheating that results when conductors are not properly screwed into their terminals.
•RCD will not protect against live-neutral shocks, because the current in the live and neutral is balanced. So if you touch live and neutral conductors at the same time (e.g., both terminals of a light fitting), you may still get a nasty shock.

A RCD whilst not permitted as the sole means of protection, is considered to greatly reduce the risk associated with contact with live parts, provided that the RCD has a rated operating current “ In “ of not more than 30 mA and an operating time not exceeding 40 ms at 5 times “ In “ , i.e. 150 mA.
As the RCD cuts out at 30mA, (or 0.03 amps). it’s very likely that someone who touches a live wire in a circuit that is protected by a RCD will survive.
RCDs should be operated monthly using the Test button to confirm they trip

A MCB (Miniature Circuit Breaker) is another type of circuit breaker that reacts to overload currents. It is designed to protect the wiring from faults caused by incorrect use. Its main role is safety and is designed to reduce the chances of fire from overloaded circuits.

A MCB will trip rapidly if the current through it exceeds 1.5 x its rated value. This is generally quite a high value and if someone were to touch a live wire in a circuit that is protected only by a MCB there’s a good chance they’ll be killed. Replacing an MCB rated at 40A with one that's rated 60A would not be recommended same as you should not replace a plug top fuse rated 5 amp with a 13 amp fuse if it was to constantly blow. The reason for it blowing is there is a fault somewhere in the circuit or device
As the two types of safety device protect against different risks, it’s often required to have both in an installation. One RCD to protect the users from electrical shock risk and several MCBs to protect the various sub circuits against overload.

There some types which are a combination of both an RCD and MCB called RCBOs
An RCBO is a single device which combines the functions of an MCB (over-current and short-circuit protection) and an RCD (Earth fault protection).

Regardless of the MCB load rating ie 16A, 32A, 40A the maximum rating for earth fault protection within domestic premises should be 30mA