With the use of integral DC source equipment increasing, Type B Earth Leakage relays provide protection against DC and AC leakage currents.
The increased usage of Electric Vehicle Chargers (EVC) highlights the need for DC leakage currents protection. Although Type A Earth Leakage relays and RCDs tolerate upto 6mA DC leakage, they’re not designed to product against DC leakage. Type B devices however, are specifically designed for detection and protection against DC and AC Leakage current.
When multiple EVCs are used, it is very likely the potential DC leakage current will exceed 6mA. Causing a phenomenon in Type A devices known as “blinding’ resulting with the either working erratically or not at all.
Aswell as EVCs producing DC Leakage current, most of the equipment with some form of variable control will also have the potential for DC leakage currents.
Type B devices are designed to protect against DC leakage currents and provide “future proofing” for installations. It is inevitable that potential DC leakage currents will increase, particularly with the installation of EVCs.
Fitting Type B Earth Leakage devices provides the correct protection and prevents the need for future costly shut downs to allow for upgrading of Type A devices.
For more information please contact Proteus Switchgear or visit their site
