Type 2 Surge Protection Devices that stop induced surges before they reach your panels
IEC 61643-11 Class II / Type 2 SPDs for distribution boards, sub-panels and machine control panels. In 20 kA (8/20 µs), Imax 40 kA, Up ≤ 1.5 kV, pluggable modules with thermal disconnect and remote-signal contact. Built, tested and certified by LPES in Gurugram, shipped across India and exported to the GCC, Africa and Europe.
Get a QuoteTalk to an EngineerWhat is a Type 2 surge protection device?
Type 1 vs Type 2 vs Type 3 — which class do you need?
| Type 1 (Class I) | Type 2 (Class II) | Type 3 (Class III) | |
|---|---|---|---|
| Test wave | 10/350 µs (Iimp) | 8/20 µs (In / Imax) | Combination wave 1.2/50 – 8/20 µs (Uoc) |
| Handles | Direct lightning current from an LPS or overhead line | Induced and switching surges | Residual surge at the equipment |
| Where installed | Service entrance / main LT panel of a building with an LPS | Main DB (no LPS) and every sub-DB, MCC, PCC, control panel | At the socket or inside the equipment, within 10 m of the load |
| Typical rating | Iimp 12.5–25 kA per pole | In 20 kA, Imax 40 kA per pole | Uoc 6–20 kV |
| Protection level Up | ≤ 2.5 kV | ≤ 1.5 kV | ≤ 1.0 kV |
| Standards | IEC 61643-11 Class I, IS 16463 | IEC 61643-11 Class II, IS 16463 | IEC 61643-11 Class III, IS 16463 |
| LPES range | Type 1 and Type 1+2 SPD | Type 2 SPD, Single Phase, Three Phase | Type 3 SPD, Type 2+3 SPD |
Ratings are per IEC 61643-11 Ed. 1.0 and IS 16463 (Part 11). Up values are for 230/400 V, 50 Hz systems at the rated discharge current.
Type 2 SPD range from LPES
Single Phase Type 2 SPD
1P+N / 2P, Uc 275 V or 320 V, In 20 kA, Imax 40 kA. For lighting DBs, small panels, homes and shops.
View single phase models →Three Phase Type 2 SPD
3P+N / 4P, Uc 275 V or 320 V, In 20 kA, Imax 40 kA. For MCC, PCC, sub-DBs and machine panels.
View three phase models →Type 1+2 Combined SPD
Iimp 12.5 kA + In 20 kA in one device for the main panel of buildings with an LPS.
See Type 1+2 SPD →All Type 2 SPDs
Every Type 2 model, pole configuration and Uc rating in the catalogue, with pricing for logged-in dealers.
Browse the full range →How to select a Type 2 SPD
1. Match the maximum continuous operating voltage (Uc) to the network
Uc must be above the highest voltage the SPD will see continuously, including neutral shift on TT networks. For a 230/400 V TN-S or TN-C-S supply use Uc 275 V. For TT networks, unstable rural supplies, DG sets or long feeders where voltage regularly runs high, use Uc 320 V — it costs a little in Up but the SPD will not age prematurely from temporary overvoltages. LPES lists Uc on every model page so you can filter for it.
2. Choose the pole configuration for the earthing system
| Earthing system | Configuration | Notes |
|---|---|---|
| TN-S (separate N and PE) | 4P (L1, L2, L3, N to PE) or 3P+N | Most industrial panels in India |
| TN-C (combined PEN) | 3P (L1, L2, L3 to PEN) | No neutral module needed |
| TT (local earth electrode) | 3P+N (CT2: three MOVs L–N plus a gas discharge tube N–PE) | Prevents earth-fault trip of the RCD |
| Single phase | 1P+N or 2P | Use 1P+N on TT |
3. Check In, Imax and the protection level Up
In 20 kA (8/20 µs) is the rating an SPD must survive 15 times; Imax 40 kA is the single-shot ceiling. For a sub-DB fed by an upstream Type 1, In 20 kA is enough. For the main DB of a building without an LPS in a high-flash-density region (Ng above 5 per km² per year — most of north and east India), specify Imax 40 kA or step up to a Type 1+2. Then confirm Up ≤ 1.5 kV is below the impulse withstand of the equipment you are protecting (Category II equipment, 2.5 kV, with margin).
4. Keep the connecting leads short
Every metre of lead between the busbar, the SPD and the earth bar adds roughly 1 kV of inductive voltage at 20 kA. Keep total lead length under 0.5 m, run the phase and earth leads side by side, and use 6 mm² copper minimum (16 mm² where the SPD also sees Type 1 duty). If the leads cannot be kept short, use the V-connection (Kelvin) wiring shown in the LPES datasheet.
5. Provide the backup overcurrent device
An SPD that fails at end of life must be isolated. Each LPES Type 2 module has an internal thermal disconnector; the external backup is an MCB or gG fuse sized per the datasheet (typically 32 A gG or a C-curve MCB where the upstream device exceeds 125 A). Use the remote-signal contact on the base to wire the SPD status into the panel annunciator or BMS.
6. Coordinate with the upstream Type 1
Where a Type 1 is installed at the service entrance and a Type 2 downstream, allow 10 m of cable between them or use a decoupling inductor so that the Type 1 takes the bulk of the energy. LPES Type 1 and Type 2 ranges are energy-coordinated, so the pairing is tested rather than assumed.
Limitations and trade-offs
A Type 2 SPD does not replace a lightning protection system and cannot carry direct lightning current — on a structure with an LPS, on an overhead LT supply, or on a rooftop solar plant it must sit behind a Type 1 or be replaced by a Type 1+2. It also protects only the circuit it is connected to: sensitive electronics more than 10 m downstream need a Type 3 at the equipment. Finally, an SPD is only as good as the earth it discharges into — target an earth resistance of 1 Ω for substations and below 5 Ω for panels, measured, not assumed.
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
What is the difference between a Type 1 and a Type 2 SPD?
A Type 1 SPD is tested with the 10/350 µs lightning-current wave and is installed at the service entrance of buildings that have a lightning protection system or an overhead supply. A Type 2 SPD is tested with the 8/20 µs wave and protects against induced and switching surges in main and sub-distribution boards. Most installations use both, energy-coordinated, or a combined Type 1+2 device.
Where should a Type 2 surge protection device be installed?
In the main distribution board if the building has no external lightning protection, and in every sub-distribution board, MCC, PCC and machine control panel downstream of a Type 1. Install it as close to the incoming terminals as possible with connecting leads under 0.5 m total.
What does In 20 kA and Imax 40 kA mean?
In is the nominal discharge current (8/20 µs) the SPD must withstand 15 times without failing. Imax is the maximum single-shot discharge current. In 20 kA / Imax 40 kA is the standard rating for Type 2 SPDs under IEC 61643-11 and IS 16463.
Should I choose Uc 275 V or Uc 320 V?
Use Uc 275 V for stable TN-S or TN-C-S supplies. Use Uc 320 V on TT networks, DG-fed or rural supplies where temporary overvoltages are common; the higher Uc extends the life of the MOV at a small cost in protection level.
Does a Type 2 SPD need a backup MCB or fuse?
Yes. Every SPD needs an external overcurrent device unless the upstream protection is already within the value stated in the datasheet. LPES Type 2 modules also carry an internal thermal disconnector and a visual status window, with a remote-signal contact on the base.
Can a Type 2 SPD be used for solar PV or DC circuits?
No. AC Type 2 SPDs are rated for 50 Hz networks. DC circuits need a DC-rated SPD tested to IEC 61643-31, such as the LPES Solar PV SPD range for 600 V, 1000 V and 1500 V DC strings.
Is a Type 2 SPD mandatory in India?
IS 732:2019 (wiring of electrical installations) and the National Electrical Code 2023 require surge protection where the consequences of overvoltage affect safety, public services, commercial or industrial activity, or where a lightning protection system or overhead supply exists. Insurers and EPC specifications increasingly call for Type 2 SPDs in every distribution board.
How long does a Type 2 SPD last and how do I know it has failed?
Under normal surge exposure a Type 2 SPD lasts 10–15 years. Each LPES module has a status window that turns from green to red when the thermal disconnector operates, and a remote contact to signal the panel or BMS. Modules are pluggable and replaced without disturbing the wiring.
Related pages
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