Modular surge protectors
Surge protection devices: S24 devices for limiting transient overvoltages in AC networks.
- Types: Type 2 and Type 1+2, depending on reference.
- Networks: 1P+N and 3P+N configurations for AC.
- Format: one to four modules, depending on reference.
- Mounting: 35 mm DIN-rail fixing.
S24 surge protection devices: Type 2 and Type 1+2
Solera S24 surge protection devices (SPDs) limit transient overvoltages in AC networks. They are selected for residential, office and commercial distribution boards according to installation conditions and the equipment to be protected. The four references published in this category allow comparison of Type 2 and Type 1+2 devices for single-phase and three-phase circuits.
References, configuration and board space
| Reference | SPD type | Configuration | Modules |
|---|---|---|---|
| S24LST1N | T2 | 1P+N | 1 |
| S24LST3N | T2 | 3P+N | 2 |
| S24LST1N/12 | T1+T2 | 1P+N | 2 |
| S24LST3N/12 | T1+T2 | 3P+N | 4 |
How to select a surge protection device
First check the AC network, phases and neutral, earthing arrangement and Solera’s stated connection conditions. The choice between Type 2 and Type 1+2 depends on the installation assessment and coordination with other protective devices; device width alone does not determine the choice.
Check maximum continuous operating voltage Uc, voltage protection level Up and discharge ratings with their test conditions in the specific documentation. An SPD’s kA ratings describe impulse performance, not the normal load current the circuit can supply. Values from different test types must not be compared as if they were equivalent.
The specifications state 35 mm DIN-rail mounting. Allow the modules required by the particular reference and check conductors, earth connection and backup protection where required by the instructions. Transient protection does not by itself incorporate residual current, overcurrent or sustained overvoltage protection.
Frequently asked questions
How do S24LST1N and S24LST1N/12 differ?
Both are published as 1P+N. S24LST1N is Type 2 and occupies one module; S24LST1N/12 is Type 1+2 and occupies two. Type 1+2 is a transient protection classification, not combined sustained and transient overvoltage protection.
Do all 3P+N surge protectors occupy the same space?
No. S24LST3N is Type 2 and occupies two modules, whereas S24LST3N/12 is Type 1+2 and occupies four. Pole configuration and modular width are different characteristics; check both before planning the board.
Can these references be used on the DC side of a photovoltaic installation?
These four references are declared for AC. Do not assume compatibility with the DC side of a photovoltaic installation: that application requires a DC-specific protector validated for its voltage and connection arrangement.