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ACCESSOR I ES
— Residual current protection according to IEC 60947-2 Annex B (1)
Residual current release Both circuit-breakers and molded case switches are pre-engineered for assembly combined with residual current releases. Residual current circuit-breakers derived from the circuit-breaker are known as “mixed”, meaning that, be - sides protection against the typical overloads and short-circuits, they also provide protection for people and against earth fault currents, thus protecting against direct, indirect contacts and risk of fire. Residual current circuit-breakers derived frommolded case switches are “pure” residual current circuit-breakers, i.e. they only provide residual current protection and not the protection typical of circuit-breakers. “Pure” re - sidual current circuit-breakers are only sensitive to earth fault currents and are generally used as main switches in small panels for distribution to end users. Use of “pure” and “mixed” residual current circuit-breakers allows the insulation state of the installation to be continuously monitored. It ensures efficient protection against the risk of fire and explosions and also protects people against indirect and direct contacts, thereby integrating the compulsory measures estab- lished by the accident prevention Standards and Regulations. The residual current releases comply with the following Standards: • IEC 60947-2 Annex B; • IEC 61000 for protection against unwanted tripping. The table below gives all the residual current devices that can be used in combination with SACE Tmax XT family:
XT1 XT5 3p 4p 3p 4p 3p 4p 3p 4p 3p 4p XT2 XT3 XT4
Instantaneous residual current device
RC Inst
F
F
F
F
Selective residual current device
RC Sel XT1-XT3
F
F
F
F
RC Sel 200
F
RC Sel XT2-XT4
F-P-W
F-P-W
RC Sel XT5
F-P-W
Type B residual current device
RC Type B XT3
F
Tmax XT residual current devices: • are designed for XT1, XT2, XT3 and XT4 microprocessor technology and act directly on the circuit-breaker by means of a dedicated opening solenoid (supplied with the residual current release and also available as a spare part) which must be housed in the relevant slot formed in the third pole on the left of the oper- ating lever; • are designed for XT5 feature microprocessor technology and act directly on the circuit-breaker by means of a dedicated mechanism integrated in the residual current itself; • do not need an auxiliary supply as they are powered directly from the mains; • can be supplied either from above or below; • provide guaranteed functionality even with a single phase plus neutral or just two live phases and in the presence of pulsating unidirectional currents with direct components (minimum auxiliary voltage PHASE-NEUTRAL 85 Vrms); • permit all possible connection combinations, as long as the neutral connection to the first pole on the left in the four-pole version is guaranteed.
(1) All the devices described in this section are not UL listed
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