High-Energy Type 1+2 AC Surge Protection for 3P+N Systems
LY1-B25/3(S)+1 is a monoblock 3P+N Type 1+2 AC surge protective device designed for TT and TN-S low-voltage distribution systems. It combines high-energy MOV and GDT protection elements to protect three-phase plus neutral incoming power circuits from lightning surges and transient overvoltage.
Class I+II / Type 1+2 AC SPD for main distribution board protection
3P+N protection design for TT and TN-S network systems
High-energy MOV and GDT elements for L-N and N-PE protection
100kA total discharge current for high-energy surge protection
Suitable Applications
LY1-B25/3(S)+1 is suitable for TT and TN-S three-phase plus neutral AC systems where Type 1+2 surge protection is required at the incoming power side or main distribution level.
Main Distribution Boards
For incoming surge protection in 3P+N AC distribution boards and low-voltage panels.
Edificios comerciales
Helps protect commercial building power systems with three-phase plus neutral distribution.
Industrial Power Panels
Suitable for industrial low-voltage panels requiring high-energy Type 1+2 surge protection.
Solar AC Side Panels
Can be used on the AC side of solar systems when voltage, network system, and protection mode match the design.
PREGUNTAS FRECUENTES
Common questions about LY1-B25/3(S)+1 3P+N monoblock AC surge protective device selection and application.
What is LY1-B25/3(S)+1 used for?
LY1-B25/3(S)+1 is used for Type 1+2 AC surge protection in TT and TN-S three-phase plus neutral systems. It protects L-N and N-PE paths at the main distribution board or incoming power side.
What does 3P+N mean?
3P+N means the SPD is designed for three-phase plus neutral systems, with protection paths between L-N and N-PE depending on the system design.
What surge ratings does this SPD provide?
The product provides 25kA / 100kA impulse discharge current Iimp, 25kA / 100kA nominal discharge current In, 100kA maximum discharge current Imax, and 100kA total discharge current Itotal.
What is the role of MOV and GDT in this SPD?
The MOV helps clamp transient overvoltage quickly, while the GDT is used for high-energy discharge, especially in the N-PE protection path.
Does this model support remote signalling?
Yes. The “S” version can include optional remote contact for SPD status monitoring. Please confirm this requirement before ordering.
What should be confirmed before ordering?
Please confirm system voltage, TT or TN-S network system, L-N / N-PE protection mode, backup fuse, installation space, wiring cross-section, and remote signalling requirement before ordering.











