Suitable for installation in Sentry consumer units & four module enclosures. When used as a mains incomer these units will provide discrimination with downstream instantaneously operating 10m A or 30 m A RCDs. For example they can be used as main incomers on split load consumer units where it is not desirable because of the possibility of unwanted tripping to place all of the circuits on an instantaneous 30m A RCD but where earth leakage protection is still required for these circuits or where compliance is required to the indirect contact protection requirements of the IEE wiring regulations.