Created by: Glen Zhu | Updated Date: August 14th, 2024
It connects directly to the power entry point and diverts surge currents to the ground, protecting the entire electrical system.
Before installing the SPD, turn off the upstream MCCB or MCB. During installation, follow the 50-centimeter installation rule. Connect the signal wire from the SPD’s floating switch to the red and green lights on the control panel, ensuring correct signal transmission.
Surge protection, for example, involves a combination of devices such as surge protectors, lightning rods, and suppressors strategically placed within an electrical system. It encompasses concepts such as equipotential bonding, emphasizing the importance of maintaining uniform electrical potential across connected equipment and structures.
The wiring diagram for a Type 1 SPD (Surge Protective Device) illustrates how to correctly connect the device to the electrical system.
Main Switch (ACB / MCCB) | Dedicated MCCB / MCB or Dedicated Fuse | Surge Protective Device | |
ACB ≥ 630A MCCB = 315A ~ 630A | 200A | 315A 250A | Type 1 SPD FLP25 series Iimp (10/350μs): 25kA |
MCCB 400A MCCB 200A | 125A ~ 100A | 125A | Type 1+2 SPD FLP12,5 series Iimp (10/350μs): 12,5kA |
MCCB 200A | 80A ~ 50A | 80A | Type 1+2 SPD FLP7 series Iimp (10/350μs): 7kA |
100A 63A | 40A ~ 32A | 40A 32A | Type 2 SPD SLP40 series In (8/20μs): 20kA Imax (8/20μs): 40kA |
/ | 20A | 20A | Type 2+3 SPD SLP20 series In (8/20μs): 10kA Uoc (1.2/50μs): 20kV |
/ | 16A ~ 10A | 16A ~ 10A | Type 3 SPD TLP series Uoc (1.2/50μs): 2kV In (8/20μs): 1kA |
Mount the Surge Protector: Install the Type 1 surge protector near the main electrical panel, close to the incoming power line.
Different levels of surge protective devices (SPDs) are installed at the entrance where the line enters the building, at the interface of lightning protection zones, and near protected equipment.
The connection wires for each level of surge protector should be short and straight, with a length not exceeding 0.5m, and firmly fixed.
The grounding end of the surge protective device (SPD) should be connected to the equipotential grounding terminal board in its lightning zone by the shortest distance possible.
The protective ground wire (PE) of distribution box should be directly connected to equipotential grounding terminal board.
Power lines with terminal blocks for surge protector device (SPD) should use crimping. Surge protector device (SPD) with wire columns should connect wiring terminals to wire columns.
The minimum cross-sectional area of surge protector device (SPD) connection wires must comply with following table:
SPD level | SPD types | cross-sectional area of the wire (mm2) | |
copper wire for SPD connection to the phase line | copper wire for SPD ground terminal connection | ||
First level | switching type or voltage-limiting type | 6 | 10 |
Second level | voltage-limiting type | 4 | 6 |
Third level | voltage-limiting type | 2.5 | 4 |
Table 1 – Minimum Cross-Sectional Area of Connection Wires for Surge Protective Device
Note: For combined SPDs, select the cross-sectional area according to the corresponding level.
Note: For combined SPDs, select the cross-sectional area according to the corresponding level.
The minimum cross-sectional area of each component connected by lightning protection and equipotential bonding should comply with the following table:
Equipotential connection components | Material | Cross-sectional area (mm2) | ||
Equipotential bonding strip (copper, steel with copper plating on the surface, or hot-dip galvanized steel) | Cu (Copper), Fe (Iron) | 50 | ||
Connecting conductors from the equipotential bonding strip to the grounding system or between different equipotential bonding strips | Cu (Copper) | 16 | ||
AI (Aluminum) | 25 | |||
Fe (Iron) | 50 | |||
Connecting conductors from indoor metal installations to the equipotential bonding strip | Cu (Copper) | 6 | ||
AI (Aluminum) | 10 | |||
Fe (Iron) | 16 | |||
Conductors connecting the surge protector | Electrical system | Type I tested surge protector | Cu (Copper) | 6 |
Type II tested surge protector | 2.5 | |||
Type III tested surge protector | 1.5 | |||
Electronic system | Class D1 surge protector | 1.2 | ||
Other types of surge protectors (connection conductors may have a cross-sectional area less than 1.2 mm²) | Determine based on the specific situation | |||
Table 2 – Minimum Cross-Section of Each Connection Component of Lightning Protection Device
Main Electrical Panel: The central distribution point where electrical power enters a building or facility.
Main Distribution Board (MDB): The primary distribution panel that divides electrical power into subsidiary circuits.
Main Circuit Breaker Panel: The panel that houses the main circuit breaker and often serves as the point of SPD installation.
Electrical Cabinets: Enclosures that house electrical components, including main distribution panels and SPDs.
Service Entrance Panel: The panel located at the point where utility power enters the building.
For example: Type 1 SPD Iimp 25kA, Main MCCB is 250A or 315A, the dedicated MCCB selects 160A or Fuse 200A.
LSP’s reliable surge protection devices (SPDs) are designed to meet the protection needs of installations against lightning and surges. Contact our Experts!
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