SURGE ARRESTER ELTAKO MUA-20 T2+T3,3L+N+PE

Overvoltage protector MUA-20 reliably protects electrical systems from transient overvoltages. It protects TN and TT systems against switching overvoltages and indirect lightning strikes. Its compact design, simple DIN-rail mounting, and modular construction enable quick installation and maintenance. It provides Type 2 + Type 3 protection and reliably guards against transient overvoltages caused by network switching operations or distant lightning strikes. The use of MUA-20 is recommended, for example, when the cable length between the main/metering distribution board and the sub-distribution/distribution board exceeds 10 meters. If a building has an external lightning protection system, staged overvoltage protection must be implemented: Type 1 in the main/metering distribution board (e.g., MUA-100, MUA-50). Type 2 in sub-distribution/distribution boards (e.g., MUA-30, MUA-20). Type 2 overvoltage protection in a sub-distribution board is required only if the cable length from the main distribution board, which is equipped with Type 1+2+3 overvoltage protection, exceeds 10 meters. TECHNICAL DATA Grounding system TN/TT Rated voltage 230/400V Maximum operating voltage 275V Nominal discharge current 20kA Maximum discharge current 40kA Protection level ≤ 1.2kV Response time ≤ 25ns Overcurrent protective device (max.) 125 A gL/gG Short-circuit withstand capacity at maximum overcurrent 25kA Protection class IP20 Conductor terminals 35mm² 4 modules = width 72 mm Spare module EM/MUA-20 (Serial No. 32 091 05) Guide for selecting overvoltage protectors Main Distribution Board / Metering Distribution Board Does the building have an external lightning protection system (class 3 or 4)? - Select MUA50. Does the building have an overhead line supply or is it located in a rural or sparsely populated area? - Select MUA30 or MUA50. Is the building located in a densely populated urban area? - Select MUA20. Sub-Distribution Board / Distribution Board Is the incoming supply cable to the sub-distribution board longer than 10 m? - Select MUA20. Is the incoming supply cable to the sub-distribution board shorter than 10 m? - Overvoltage protection is not required. This product description is an automated translation of the original Finnish description.