| Metal-Oxide, Gapless Distribution Arrester | Medium-voltage distribution transformers, overhead feeders, cable terminations, and pole-mounted equipment. | Uses non-linear metal-oxide blocks without series gaps. Provides fast response and low residual voltage for distribution equipment. | Install as close as practical to the protected equipment. Keep phase and earth leads short, straight, and separated from sensitive control wiring. Connect the earth terminal to a low-impedance grounding system. | Check nameplate ratings, physical condition, terminal tightness, clearances, grounding continuity, and correct phase connection. Perform leakage-current or reference-voltage testing only with suitable calibrated equipment and the applicable manufacturer procedure. | Inspect after severe lightning activity and during scheduled equipment outages. Look for cracked housings, contamination, corrosion, tracking, displaced disconnectors, and signs of thermal damage. Replace units showing permanent damage or abnormal test results. | System maximum continuous operating voltage, temporary overvoltage withstand, nominal discharge current, line discharge class, residual voltage, pollution level, housing material, and altitude. | IEC 60099-4; IEEE C62.11; IEEE C62.22; IEC 60099-5; IEC 62305 where the arrester forms part of a lightning protection system. |
| Metal-Oxide, Gapless Station-Class Arrester | High-voltage substations, generator step-up transformers, transmission transformers, busbars, and major switching equipment. | Designed for higher energy capability, greater electrical stress, and more demanding protective-performance requirements than ordinary distribution arresters. | Position near transformer or apparatus terminals. Maintain specified phase-to-earth and phase-to-phase clearances. Use a short, mechanically supported earth connection and bond the arrester ground to the substation grounding grid. | Verify rated voltage, continuous operating voltage, discharge class, energy capability, and protective levels. Conduct visual inspection, grounding checks, connection torque verification, and approved electrical diagnostic tests before energization. | Use condition-based maintenance supported by operating records, thermal imaging where appropriate, leakage-current trend analysis, and inspection of pressure-relief or monitoring devices. Investigate any sudden change from the established baseline. | System insulation level, transformer insulation coordination, switching surge exposure, temporary overvoltages, energy duty, nominal discharge current, altitude, seismic requirements, and pollution severity. | IEC 60099-4; IEEE C62.11; IEEE C62.22; IEC 60071-1; IEC 60071-2; IEC 62305 where applicable. |
| Metal-Oxide Line Arrester | Overhead lines exposed to direct or nearby lightning, especially in areas with frequent faults, poor shielding, or high ground resistance. | Installed directly on or alongside conductors to reduce lightning-related outages. May include a series disconnector or fault indicator depending on the design. | Mount securely to the structure and maintain the specified conductor connection and earth clearance. Keep the grounding conductor as short and direct as possible. Confirm that mechanical loads and conductor movement will not damage the arrester. | Confirm phase assignment, mounting security, conductor clamps, earth continuity, disconnector position, and clearance from grounded structures. Inspect for transport damage and contamination before installation. | Inspect after lightning-related line trips and severe storms. Check housing condition, mounting hardware, disconnector status, corrosion, bird contamination, and earth connections. Record failed units and investigate repeated operations. | Line insulation level, conductor-to-ground voltage, fault current capability, lightning exposure, line length, tower or pole grounding, mechanical loading, and required energy rating. | IEC 60099-4; IEEE C62.11; IEEE C62.22; IEC 62305; applicable national overhead-line and electrical safety regulations. |
| Gapped Line Arrester | Overhead distribution and transmission lines where temporary overvoltage behavior, follow current, or specific line-protection arrangements must be controlled. | Uses an external or internal series gap with an arrester element. The gap helps isolate the arrester from normal system voltage but requires accurate installation geometry. | Follow the specified gap distance, alignment, conductor attachment, and mounting orientation. Prevent contamination, vegetation, or hardware from bridging the gap. Verify clearances under expected conductor movement. | Inspect gap spacing and alignment using the approved dimensional method. Check earth continuity, mounting condition, conductor connections, and any disconnector or fault indicator. Do not energize if the gap is contaminated or mechanically displaced. | Inspect gap electrodes for erosion, contamination, corrosion, and incorrect spacing. Recheck after major storms, line work, or mechanical incidents. Replace components that no longer meet the specified gap or insulation condition. | Sparkover voltage, power-frequency withstand, lightning impulse performance, follow-current behavior, line fault current, gap geometry, and environmental pollution level. | IEC 60099-6 where applicable; IEC 60099-4 for relevant metal-oxide arrester elements; IEC 62305; applicable national grid requirements. |
| Porcelain-Housed Arrester | Outdoor medium- and high-voltage substations and installations requiring established mechanical and electrical housing technology. | Provides a rigid ceramic enclosure with good outdoor insulation performance. It is heavier and more vulnerable to impact damage than polymeric housings. | Use suitable lifting equipment and avoid impact during transport and erection. Install on a level support, maintain creepage and clearance distances, and protect the porcelain from mechanical stress and excessive terminal loading. | Inspect for chips, cracks, glaze damage, contamination, moisture ingress, and loose hardware. Verify grounding, terminal connections, support alignment, and any pressure-relief path before energization. | Clean according to the site pollution-control procedure. Inspect for cracking, chalking, corrosion, water ingress, and flashover marks. Thermal or electrical diagnostic tests should be compared with previous results, not judged from a universal limit alone. | Mechanical load, seismic duty, creepage distance, pollution severity, altitude correction, enclosure pressure-relief behavior, and required insulation coordination. | IEC 60099-4; IEEE C62.11; IEC 60815 for creepage and pollution considerations; IEC 60071-1 and IEC 60071-2. |
| Polymeric-Housed Arrester | Outdoor distribution, renewable-energy collection systems, substations, compact switchyards, and locations with high pollution or demanding weight restrictions. | Uses a lightweight polymeric housing, commonly with weather-shed profiles and an integral sealing system. Offers good handling and reduced breakage risk, subject to material and design quality. | Avoid cutting, drilling, or compressing the housing. Maintain the specified bending radius and terminal torque. Confirm that the housing is suitable for ultraviolet exposure, pollution, altitude, and local climate. | Check for cuts, punctures, tracking, erosion, discoloration, loose sheds, seal damage, and incorrect mounting. Verify grounding, phase connection, clearances, and any pressure-relief or disconnector indication. | Inspect polymer surface aging, erosion, hydrophobicity loss, contamination, animal damage, and ultraviolet degradation. Clean only with approved methods that do not damage the housing. Replace units with structural or sealing defects. | Housing material, weather-shed profile, creepage distance, pollution level, UV and climate resistance, mechanical cantilever load, energy rating, and sealing performance. | IEC 60099-4; IEEE C62.11; IEC 60815; IEC 60071-1; IEC 60071-2; applicable environmental and electrical installation rules. |
| Low-Voltage Surge Protective Device, Type 1 | Main incoming power distribution where partial lightning current may enter the installation, particularly when an external lightning protection system is present. | Designed for high-energy transient currents at the service entrance. Usually installed upstream of or near the main overcurrent protective arrangement according to the applicable wiring rules. | Install with very short connecting conductors, correct backup protection, suitable enclosure spacing, and a reliable main protective bonding connection. Coordinate with downstream surge-protection stages. | Verify wiring configuration, protective-device rating, backup fuse or breaker, status indicator, conductor length, bonding, and insulation clearances. Test according to the applicable low-voltage installation standard and device instructions. | Check status indicators during routine electrical inspections and after suspected surge events. Replace modules or the complete device when the end-of-life indicator operates or when physical damage is visible. | System earthing arrangement, maximum continuous operating voltage, nominal discharge current, impulse current rating, voltage-protection level, short-circuit rating, and backup protection. | IEC 61643-11; IEC 60364-4-44; IEC 62305; applicable national low-voltage wiring regulations. |
| Low-Voltage Surge Protective Device, Type 2 | Distribution boards, commercial buildings, industrial panels, control cabinets, and downstream circuits requiring protection from induced or conducted surges. | Designed primarily for residual surge energy after upstream protection. Commonly uses metal-oxide varistors and may be installed as a modular device with visual status indication. | Install downstream of the main incoming protection with short leads and correct line, neutral, and protective-earth connections. Observe required coordination distance or use a coordinated protection system. | Check circuit configuration, continuous operating voltage, protection level, backup protection, conductor routing, earth connection, and status indicator. Confirm that the device is suitable for the system earthing arrangement. | Inspect status indicators and terminals during panel maintenance. Replace the module or device after an end-of-life indication, major surge event, overheating, or visible deterioration. | Nominal discharge current, maximum discharge current, voltage-protection level, continuous operating voltage, response characteristics, short-circuit rating, and coordination with Type 1 or Type 3 protection. | IEC 61643-11; IEC 60364-4-44; IEC 62305; applicable national electrical installation regulations. |
| Low-Voltage Surge Protective Device, Type 3 | Final protection near sensitive electronic equipment, instrumentation, communication equipment, building automation, and information-technology loads. | Provides fine protection at the equipment level but has lower energy-handling capability than service-entrance and distribution-stage devices. | Install close to the protected load and use short, correctly routed conductors. Do not use as the only protection where direct or substantial lightning current can enter the installation. | Verify compatibility with the upstream protection stages, equipment voltage, plug or terminal arrangement, grounding method, and status indication. Confirm that signal and power protection are coordinated where necessary. | Check indicators, plugs, terminals, enclosure condition, and equipment nuisance-trip history. Replace after an end-of-life indication or a confirmed surge event. | Voltage-protection level, nominal discharge current, load current, system voltage, response time, connector arrangement, and compatibility with upstream Type 1 or Type 2 protection. | IEC 61643-11; IEC 60364-4-44; IEC 62305; applicable product and installation requirements for the protected equipment. |
| Signal and Data-Line Surge Protector | Industrial communication networks, measurement circuits, control systems, security systems, telecommunications, and outdoor sensor cabling. | Protects signal conductors from common-mode and differential-mode surges while aiming to preserve the operating bandwidth and signal integrity. | Install at cable entry points and near sensitive equipment when required. Match conductor configuration, impedance, operating frequency, shielding, grounding method, and connector type. Avoid ground loops. | Verify line assignment, polarity, shielding, earth bonding, insertion loss, continuity, insulation condition, and communication performance. Use suitable test equipment for the interface type. | Inspect connectors, shield bonds, grounding conductors, corrosion, moisture ingress, and status indicators. Test communication quality after maintenance and replace damaged protection modules. | Maximum operating voltage, nominal discharge current, clamping voltage, bandwidth, insertion loss, capacitance, common-mode and differential-mode protection, and shield termination method. | IEC 61643-21; IEC 61643-22; IEC 62305; applicable telecommunications, industrial-control, and electromagnetic-compatibility requirements. |
