Residual Current Devices, RCDs & RCBOs
(Earth Leak/Ground Faults) (GFCIs)
Our range of RCCBs and RCBOs provide all the options
you need for complete protection against earth leakage and residual
current faults and additionally offer combined earth leak and overload
protection in RTEC and SmartGuard ranges.
The RCD range (CTEC) from Techna offers both 2 and 4 pole devices in
30mA - 500mA trip sensitivities, with main current ratings of 25A, 40A,
63A and 100A.
The RCD protects against residual currents (earth leaks/ground faults), where a small
current may leak from the circuit due to bad insulation. Critically the
residual current device will react to leakage currents as low as 30mA.
This is an essential protection requirement as earth leaks at these low
currents are too small to trip a conventional circuit breaker, but still
large enough to cause fatal electric shock and/or start fires due to
arcing. The sensitivity of the RCD is defined by its mA rating. The main
current rating of the device denotes only the maximum current the RCD
can carry and does not affect the protection characteristics. So, for
example, if you required a 25A/30mA RCD, you could also use a 40A/30mA
or 63A/30mA. However, the lower current device (25A) costs less as the
lower rated contact mechanism is less expensive to produce.
The RTEC RCBO protects against residual currents (earth leaks) and short
circuits (overloads). An RCBO can be used where a single device is
needed to provide both earth leak and overload protection, perhaps
because the circuit is not fed from an RCD protected branch. This is
useful for wiring spurs and pieces of equipment that could also benefit
from space saved by using the single RCBO device (as opposed to a
separate MCB and RCD). As the short circuit sensing is only on the live
pole, it is essential that live and neutral are wired correctly to the
RCBO as indicated on the front of the device.
Due to the additional overload feature of our RTEC
RCBO, when ordering, the main current rating must also be specified
to match the main current rating of your circuit. |
