Compact Type 2+3 AC Surge Protection for 3P+N Systems
LY1-D20/4(S) is a four-pole pluggable Type 2+3 AC surge protective device designed for three-phase plus neutral distribution systems. Its high-energy MOV modules provide coordinated surge suppression across phase and neutral paths, with 10kA nominal discharge current and 20kA maximum discharge current for downstream and final-distribution protection.
Class II+III / Type 2+3 protection for downstream AC systems
4P / 3P+N design for three-phase four-wire circuits
10kA nominal and 20kA maximum discharge current
Replaceable cartridges with visual indication and optional remote contact
Suitable Applications
LY1-D20/4(S) is suitable for three-phase plus neutral downstream and final-distribution AC systems requiring coordinated four-pole Type 2+3 surge protection.
Schede di sottodistribuzione
For downstream protection in commercial and industrial three-phase plus neutral distribution panels.
Industrial Control Panels
Suitable for machinery controls, production equipment, HVAC systems, and factory automation cabinets.
Commercial Facilities
Helps protect offices, shopping facilities, building automation systems, and commercial electrical loads.
Solar Inverter AC Panels
For three-phase solar inverter AC-side panels when the selected Uc version matches the system voltage.
FAQ
Common questions about LY1-D20/4(S) four-pole pluggable Type 2+3 AC surge protective device selection and installation.
What is LY1-D20/4(S) used for?
LY1-D20/4(S) is used for downstream surge protection in three-phase plus neutral AC distribution systems. It is suitable for sub-distribution boards, control cabinets, commercial power systems, and final equipment circuits.
What does 4P or 3P+N mean?
4P or 3P+N means the SPD provides protection for three phase conductors and the neutral conductor in a three-phase four-wire electrical system.
Is LY1-D20/4(S) a Type 2 or Type 3 SPD?
LY1-D20/4(S) is classified as Class II+III / Type 2+3, making it suitable for coordinated downstream and final-distribution surge protection.
What discharge current ratings does it provide?
It provides 10kA nominal discharge current In and 20kA maximum discharge current Imax, both based on the 8/20μs current waveform.
What voltage options are available?
Available maximum continuous operating voltage options are 75V, 150V, 275V, 320V, 385V, and 440V AC. Select the correct version according to the nominal system voltage.
What should be confirmed before ordering?
Confirm the nominal system voltage, required Uc and Up level, 3P+N protection arrangement, 125A maximum backup-fuse coordination, conductor size, DIN-rail space, and remote-contact requirement.











