Low-voltage AC transient protection at an identified network connection
A low-voltage AC surge protective device limits transient voltage at an electrical installation. Select it for the actual network configuration, installation point and protective-device arrangement. Surge-current capacity, voltage protection and short-circuit behavior describe different tests.
Low-voltage AC surge protective devices for service entrances, distribution or branch panels and equipment, including products classified under the applicable UL or IEC scheme. Medium-voltage line/station arresters, PV/DC-only devices, data-line protectors and arrester test equipment are outside this page.
CNFX editorial research · Sources checked October 18, 2026 · 5 sources
Keep surge-current capacity separate from fault-current rating
Raycap’s reference guide distinguishes RSE stacked-MOV products from Strikesorb-based Rayvoss systems. Its application table identifies model-specific test and installation arrangements; the technologies and listed ratings must not be transferred across the whole range. [1]
The RSE Series 1 sheet separately lists maximum surge current of 25–50 kA per mode, UL nominal discharge current of 20 kA and short-circuit current rating of 200 kA. These are not alternative names for the same current capacity. Its UL type designation is Type 1 and Type 2; apply the product’s installation listing rather than assuming UL type labels and IEC test classes are interchangeable. [2]
The guide labels its surge ratings by mode/phase. Compare like-labelled quantities rather than adding protection modes or doubling a per-mode figure to claim a new tested rating. Its short-circuit table footnote also refers to an appropriately rated breaker for the marked arrangements. [1]
02
Match the system configuration and the protected mode
Raycap’s RSE Series 1 sheet gives different voltage-protection ratings by system and mode. For 480Y/277 V, it lists 1,200 V for L-N, L-G and N-G, 2,000 V for L-L, and MCOV 320 V. Those figures belong to that configuration; they do not specify a delta-system connection or the correct device for every network. [2]
The DEHNguard DG M TNS 275 sheet identifies a Type 2/IEC Class II device for 230/400 V TN-S: Uc 275 V, In 20 kA and Imax 40 kA using 8/20 µs current, and Up ≤ 1.25 kV. The separate Up ≤ 1 kV entry is at 5 kA and must retain that test-current qualifier. [3]
Nominal-voltage ratios are not a method of deriving compatibility or protective performance. Confirm the continuous-voltage rating, protection modes, temporary-overvoltage behavior and connection instructions for the actual earthing and supply arrangement.
03
Retain the waveform and test definition behind each IEC-style parameter
CITEL’s parameter guide distinguishes continuous operating voltage Uc, protection level Up, nominal discharge current In, maximum discharge current Imax, impulse current Iimp and short-circuit rating Isccr. A product’s kA figure is incomplete without identifying which quantity and test it represents. [4]
These laboratory test descriptions do not establish survival of an equal number of real lightning strikes. Real surge exposure and the installed assembly are not established by multiplying a declared current by the number of test strokes.
CITEL’s Protection Kit page labels the assembly Type 1+2 and prints a 12.5 kA @ 8/20 µs figure. Its parameter page defines Iimp with 10/350 µs. Do not relabel the kit-page figure as Iimp; obtain the exact model data sheet and confirmation of the declared current and waveform from CITEL. [5][4]
Type 2 maximum withstand for a single 8/20 µs test stroke. [4]
Iimp
Type 1 withstand defined using a 10/350 µs test stroke. [4]
Isccr
SPD and associated disconnecting device tested together for the declared short-circuit condition. [4]
04
Order the declared backup protection with the SPD
CITEL describes kits combining an SPD with a specific fuse and busbar, and says the external fuse is declared by the SPD manufacturer. Selection includes the disconnection arrangement, not just the plug-in protection module. [5]
The DEHN sheet lists maximum mains-side protection of 125 A gL/gG and short-circuit withstand of 50 kArms with the specified maximum mains-side protection. Preserve that pairing; the fuse value is not a universal breaker recommendation and the short-circuit value is not an impulse-current rating. [3]
Identify the available fault current, declared backup protection, installed conductor arrangement and the complete product’s instructions. Obtain the relevant test/listing documentation for the offered model and the local installation requirements.
05
Specify what the installed protection assembly includes
The RSE Series 1 sheet separates protection modes, thermal protection, status indication and optional alarms or contacts. Confirm the ordered options, rather than treating every monitoring function as standard. [2]
Assembly boundary
Information to obtain
Protection element and disconnection
Identified module, thermal/end-of-life behavior and declared backup protection. [2][5]
Network connection
System voltage/earthing, modes, installed conductors and connection instructions.
Status and remote indication
Supplied indication, alarm/contact options and interpretation of a failed or unpowered indication. [2]
Enclosure
Protection of the complete installation, including connections; use the identified model’s enclosure specification.
06
Attach the test basis to the quotation fields
Require the model and its declared test basis beside each rating.
Order field
Required definition
Application
AC system voltage/configuration, earthing and installation point.
Current ratings
In/Imax/Iimp or the applicable declared rating, waveform and per-mode/per-phase basis. [4][1]
Voltage protection
Uc/MCOV and Up/VPR for the stated mode and test; do not merge values from different modes. [3][2]
Fault protection
Available fault current and manufacturer-declared fuse/breaker combination. [5]
Installed package
Mounting, connections, enclosure, status and remote contacts supplied.
07
Send the system, location and ratings together
Paste it into your enquiry below or into an email to a maker, then replace every bracket.
System: [voltage; configuration; earthing]
Location: [service entrance, distribution, branch, equipment]
Ratings: [type/class; In; Imax per mode; Up; Uc; SCCR]
Connection: [parallel or in-line; conductor; breaker or fuse]
Enclosure: [DIN rail or panel; IP/NEMA]
Monitoring: [LED; alarm; dry contact; SNMP]
Standard: [UL 1449 or IEC 61643-11]
13 companies list this product among what they make. Company figures are quoted from each
company's own website; every card states where the relationship came from.
CNC Electric
TBC
Lists low-voltage AC SPDs as well as a separate DC range.
Explore company information and manufacturing capabilities, then discuss the scope of your project with a relevant supplier.
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Compiled and source-reviewed by the CNFX editorial team.
Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review
· Page last updated 13 October 2026
Buyer questions
Is a surge-current figure the same as an SPD short-circuit rating?
No. Raycap lists maximum surge current, nominal discharge current and SCCR separately. Preserve the quantity, waveform and connection/test basis with each figure. [2]
Does an In test description promise survival of repeated lightning strikes?
CITEL describes a defined laboratory waveform and repetition test. It does not establish the number of real lightning events the installed device will survive. [4]
Can the Protection Kit page’s current figure be read directly as Iimp?
The kit page prints 12.5 kA @ 8/20 µs while CITEL’s parameter guide defines Iimp with 10/350 µs. Request the exact model data sheet and confirmation rather than changing the waveform or parameter label. [5][4]
Sources and evidence scope
Sources checked 2026-10-18. Original Raycap product documents, the identified DEHN sheet and CITEL technical pages. Product ratings and test summaries do not create a shared installation rule or a lightning-strike lifetime guarantee.
