Type 1+2 Combined Surge Protection Devices for the main panel of any building with a lightning protection system
One device, both classes: Iimp 12.5 kA (10/350 µs) lightning-current capability plus In 20 kA / Imax 40 kA (8/20 µs) surge protection, Up ≤ 1.5 kV. Tested to IEC 61643-11 Class I+II and IS 16463, in 1P+N, 3P and 3P+N configurations. Manufactured and certified by LPES International.
Get a QuoteTalk to an EngineerWhat is a Type 1+2 surge protection device?
Type 1+2 vs separate Type 1 and Type 2
| Type 1+2 combined SPD | Separate Type 1 + Type 2 | |
|---|---|---|
| Lightning current (Iimp) | 12.5 kA or 25 kA per pole | 12.5–25 kA (Type 1 only) |
| Surge current (In / Imax) | 20 kA / 40 kA | 20 kA / 40 kA (Type 2 only) |
| Protection level Up | ≤ 1.5 kV | ≤ 2.5 kV at the Type 1; ≤ 1.5 kV after the Type 2 |
| Panel space | One 4-module base | Two devices, two backup fuses |
| Decoupling | Not needed | 10 m cable or decoupling inductor between the two |
| Best for | Main LT panel of a building with an LPS, overhead supply or rooftop PV | Very large service entrances (Iimp above 25 kA) with long feeders to sub-panels |
| LPES products | Type 1+2 SPD | Type 1 SPD + Type 2 SPD |
Where the lightning protection level is LPL I or II (IEC 62305-3), or the supply is TN-C with a single PEN, specify Iimp 25 kA per pole.
Type 1+2 SPD range from LPES
Type 1+2 SPD, Iimp 12.5 kA
3P+N and 1P+N, Uc 275 V / 320 V, In 20 kA, Imax 40 kA. For LPL III–IV structures and buildings on overhead LT supply.
View 12.5 kA models →Type 1+2 SPD, Iimp 25 kA
3P+N and 3P, Uc 275 V / 320 V. For LPL I–II structures, telecom towers, substations and process plants.
View 25 kA models →Type 1 SPD (spark-gap)
Iimp 25–50 kA lightning-current arresters for very large service entrances and TN-C supplies.
See Type 1 SPD →Type 2 SPD for sub-panels
The downstream partner: In 20 kA / Imax 40 kA for every sub-DB, MCC and control panel.
See Type 2 SPD →How to select a Type 1+2 SPD
1. Establish the lightning current the panel can see
IEC 62305-4 assumes 50 % of the lightning current enters the earth and 50 % is shared between the incoming services. For a three-phase four-wire supply at LPL III–IV (100 kA strike) that is 12.5 kA per conductor; at LPL I (200 kA) it is 25 kA per conductor. Use the LPES risk assessment to find your LPL, then pick Iimp 12.5 kA or 25 kA accordingly.
2. Decide whether you need Type 1+2 at all
| Situation | Main panel SPD |
|---|---|
| Building has an external LPS (air terminals, down conductors) | Type 1+2 mandatory |
| Overhead LT supply, or building taller than its neighbours in open ground | Type 1+2 |
| Rooftop solar plant on the same building | Type 1+2 on the AC side plus DC SPD at the inverter |
| Underground supply, no LPS, urban surroundings | Type 2 is sufficient |
3. Pick Uc and the pole configuration
Uc 275 V for TN-S / TN-C-S; Uc 320 V for TT networks and DG-fed sites. Use 3P+N (3+1, with a gas discharge tube N–PE) for TN-S and TT, and 3P for TN-C where the PEN acts as the reference. Single-phase incomers use 1P+N.
4. Size the backup fuse and the leads
Type 1+2 devices are wired with 16 mm² copper minimum and a backup gG fuse of 125 A or 160 A (per datasheet), unless the upstream device is already lower. Keep the combined lead length under 0.5 m; the V-connection wiring in the LPES datasheet removes lead voltage drop altogether.
5. Signal the status
Wire the remote-signal contact to the panel annunciator, PLC or BMS. On a main panel, a failed lightning arrester is a site-wide risk, and the visual window alone is checked too rarely.
Limitations and trade-offs
A Type 1+2 SPD in the main panel does not protect sub-panels more than 10 m of cable away — induced surges re-enter through the cable run, so every sub-DB still needs its own Type 2. It also does not protect the DC side of a solar plant, telecom lines or data cables; those need their own DC, telecom and signal SPDs. Iimp 12.5 kA is adequate for most Indian commercial and industrial buildings but is not enough for LPL I–II structures such as substations, hazardous-area plants and telecom towers, where 25 kA per pole is the correct specification.
Datasheets, certificates and CAD
Every LPES product ships with a datasheet, test report reference and declaration of conformity. Download the current catalogue and product datasheets from the Downloads library, or ask for the CAD block and single-line drawing for your panel from the RFQ form below.
Frequently asked questions
When is a Type 1+2 SPD required instead of a Type 2?
Whenever partial lightning current can enter the electrical installation: the building has a lightning protection system, is fed by an overhead line, stands exposed above its surroundings, or carries a rooftop solar plant. In those cases IEC 62305-4 and IS 732 call for a Class I (Type 1) device at the service entrance, and the Type 1+2 delivers that plus Type 2 protection in one unit.
What Iimp rating should I specify?
12.5 kA per pole for lightning protection level III–IV (the common case for factories, warehouses and commercial buildings); 25 kA per pole for LPL I–II structures such as substations, hazardous-area plants, hospitals and telecom towers, or for TN-C supplies where the whole current shares fewer conductors.
Does a Type 1+2 SPD replace the Type 2 in sub-panels?
No. It replaces the Type 2 in the same main panel only. Sub-distribution boards and control panels more than 10 m away still need their own Type 2 SPD because induced surges re-enter along the cable runs.
What is the difference between a spark-gap Type 1 and an MOV-based Type 1+2?
Spark-gap arresters carry very high Iimp (25–50 kA) with no leakage current but have a higher protection level and can produce follow current. MOV-based Type 1+2 devices give a lower Up (≤ 1.5 kV), no follow current and simpler coordination. LPES offers both and recommends the Type 1+2 for the majority of main panels.
Which backup fuse is used with a Type 1+2 SPD?
A gG fuse or MCB rated per the datasheet — typically 125 A or 160 A gG — installed in series unless the upstream protection is already at or below that value. The device also has an internal thermal disconnector and a status contact.
Can I use a Type 1+2 SPD on a TT network?
Yes. Use the 3P+N (3+1) configuration with a gas discharge tube between neutral and PE so that a surge does not trip the RCD and no leakage flows to earth in normal service. Specify Uc 320 V on TT networks.
Is the Type 1+2 SPD tested and certified?
Yes. LPES Type 1+2 SPDs are type-tested to IEC 61643-11 Class I and Class II (IS 16463 Part 11) with reports from CPRI / ERDA, carry CE marking and are certified in LPES International's own name.
What earth resistance is needed for a Type 1+2 SPD to work?
The SPD diverts current into the earth electrode system; the lower the resistance, the lower the voltage rise. Aim for under 5 Ω for buildings and 1 Ω for substations, measured with a fall-of-potential test, and bond the SPD earth to the main earthing terminal with the shortest possible conductor.
Related pages
Specifying the main panel SPD for a new building or plant?
Share the lightning protection level, supply type and panel SLD; LPES returns an energy-coordinated Type 1+2 and Type 2 schedule with a BOQ and datasheets.
