Read any EBB SPD code
An EBB part number tells you everything you need to specify it — family, voltage, discharge rating, signalling and poles. Build a code or click a segment to learn what it means.
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Type 2 surge arrester (MOV), 8/20 µs wave. For sub-distribution boards and equipment protection — the most common SPD on site.
Maximum continuous operating voltage. The SPD sits across live conductors at all times — Uc must exceed your system voltage with margin.
Maximum discharge current (Imax, 8/20 µs). Higher kA = more surge energy absorbed before end-of-life.
Single-pole — line to earth/PEN. For single-phase TN-C systems.
How the model name reads
Take the hero SKU — PZ-C 275/40 R 1P+N. Each segment encodes a specific parameter.
PZ-C 275 / 40 R 1P+N
│ │ │ │ │
family Uc voltage Imax remote pole config
(kA) signallingFamily — first four characters
Sets the protection class and the worst-case waveform the device is tested against.
| Code | Meaning | When to use |
|---|---|---|
PZ-A | Type 2, Class II, Group A — DIN-rail surge arrester | Downstream sub-DBs, light residential |
PZ-B | Type 1+2, Class B+C — combined lightning + surge arrester | Main building entry where an LPS is installed |
PZ-C | Type 2, Class II, Group C — surge arrester | Standard distribution boards (most common) |
PZ-M1 | Type 2 variant without internal disconnector | Where external thermal protection already exists |
Type / Class
The standard designation you will see on tender documents and installation schedules. Each type maps to a specific test waveform and installation position in the system.
| Code | Meaning | When to use |
|---|---|---|
Type 1 (Class I) | Tested for direct lightning strike — 10/350 µs waveform — Iimp rated | Building entry under a lightning rod / LPS |
Type 2 (Class II) | Tested for induced surges — 8/20 µs waveform — In and Imax rated | Distribution boards downstream |
Type 1+2 (Class B+C) | Combined — handles both direct-strike and induced surges | Entry of buildings where one device must do both jobs |
Type 3 (Class III) | Fine protection — socket-level (not in the EBB range) | Point-of-use, via a power strip with surge filter |
First number — Uc (Maximum Continuous Operating Voltage)
The highest voltage the SPD can sit at indefinitely without conducting. Select the value that matches your supply network — never under-rate it.
| Code | Meaning | When to use |
|---|---|---|
275 | 275 V ac / 350 V dc | Standard SA 230 V single-phase networks |
320 | 320 V ac | Networks with elevated voltage tolerance, some industrial |
440 | 440 V ac | Phase-to-phase protection in 400 V three-phase, IT systems, industrial |
Second number — Imax / discharge capacity (kA)
Maximum discharge current the device can handle in a single 8/20 µs surge event. Higher numbers indicate larger energy absorption headroom. Multi-module assemblies (1P+N, 3P+N, 4P) list the combined figure.
| Code | Meaning | When to use |
|---|---|---|
40 | 40 kA Imax | Single-module Type 2 — per-phase DB protection |
50 | 50 kA Imax | Single-pole Type 1+2 (5 kA Iimp series) |
60 | 60 kA Imax | Single-pole Type 1+2 (12.5 kA Iimp series) |
80 | 80 kA Imax | 2-module (single-phase) packages |
100 | 100 kA Imax | 1P+N Type 1+2, 5 kA Iimp |
120 | 120 kA Imax | 3-pole TN-C packages |
150 | 150 kA Imax | 3P Type 1+2, 5 kA Iimp |
160 | 160 kA Imax | 4-module (three-phase + N) packages |
180 | 180 kA Imax | 3P Type 1+2, 12.5 kA Iimp |
200 | 200 kA Imax | 3P+N Type 1+2, 5 kA Iimp |
240 | 240 kA Imax | 4P Type 1+2, 12.5 kA Iimp |
Suffix — after the second number
Optional codes that modify the base unit. A device with no suffix is the standard installation variant; every other suffix adds a specific capability.
| Code | Meaning | When to use |
|---|---|---|
(none) | Base unit — visual flag indicates end-of-life | Standard installation, manual status check |
R | Remote signalling — dry-contact output | Wire status back to a BMS / alarm / SCADA |
MODULE / MODUL | Replaceable plug-in cartridge — base stays, only the worn module is swapped | Maintenance-friendly installs |
GDT | Gas Discharge Tube technology | Typically the N-PE protection slot |
Pole / system configuration
Specifies how many conductors are protected and which earthing system the unit is designed for. Choosing the wrong pole configuration for your earthing system is one of the most common installation errors — a TT-system installation requires the NPE variant, not the standard N variant.
| Code | Meaning | When to use |
|---|---|---|
1P | Single-pole (one phase only) | Any earthing system |
1P+N | Single-phase + Neutral | TN-S / TN-C-S |
1P+NPE | Single-phase + Neutral + separate Protective Earth | TT |
3P | Three-phase (no neutral protected) | TN-C / 3-wire industrial |
3P+N | Three-phase + Neutral | TN-S / TN-C-S |
3P+NPE | Three-phase + Neutral + separate PE | TT |
4P | Four-pole — three phases + neutral, all protected | TN-S / TT |
TN-S (urban SA standard)
Separate neutral and protective-earth conductors throughout. Most urban South African supplies. Use 1P+N or 3P+N variants.
TT (rural / farms)
Separate local earth electrode. Farms, agricultural pumps, rural installs. Use 1P+NPE or 3P+NPE variants.
TN-C (older industrial)
Combined PEN conductor. Older industrial sites, some mining infrastructure. Use the 3P TN-C variant.
The other letters on the spec sheet
These symbols appear in datasheets and tender specs. Every value on an EBB unit is printed to IEC 61643-11 conventions.
| Symbol | Plain English |
|---|---|
Uc | Highest voltage the SPD can sit at all day, every day, without conducting. |
In | Nominal discharge current — the surge it handles repeatedly without degrading (8/20 µs wave). |
Imax | Maximum discharge current — the biggest single surge it can survive (8/20 µs wave). |
Iimp | Impulse current — direct-lightning energy it can absorb (10/350 µs wave); only on Type 1 / Type 1+2. |
Up | Voltage protection level — the residual voltage protected equipment sees during a surge. Lower is better. |
TE | Module width unit (1TE ≈ 18 mm DIN rail). 2TE = double-width module. |
Which SPD do I install where?
A quick decision flow covering the most common South African installation scenarios.
Building has a lightning rod / LPS?
│
├── YES → Main DB at building entry needs Type 1 or Type 1+2
│ │
│ ├── Light commercial / residential → PZ-B 5 kA Iimp series
│ └── Industrial / mining / telecoms / large solar
│ → PZ-B 12.5 kA Iimp series
│
│ Then in each downstream DB → PZ-C (Type 2)
│
└── NO → Type 2 protection is sufficient
│
└── At every DB → PZ-C, matched to your earthing system:
• TN-S (urban SA standard) → PZ-C ... 1P+N / 3P+N
• TT (rural, farms) → PZ-C ... 1P+NPE / 3P+NPE
• TN-C (older industrial) → PZ-C ... 3P (TN-C variant)
• Sub-DBs downstream → PZ-AStill unsure which SPD fits your installation?
Send Mphatso your system type, supply voltage, and DB position — he will specify the right EBB SKU and confirm SANS compliance. Response within one business day.
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