Why a 4-pole differential switch?
In Belgian installations, the 4-pole differential switch is the standard model as soon as an installation includes three-phase 3N~ 400/230 V, which is common in contemporary residential, tertiary and light industry.
A 4P differential switch ensures:
- monitoring of the 3 phases + neutral,
- the measurement of the complete vector sum, essential when several single-phase circuits are distributed between phases,
- personal protection (30 mA) or fire protection (300 mA) depending on its role in the installation.
It is naturally required in several situations:
- Three-phase switchboard with distributed single-phase circuits: the most reliable and common way to monitor the entire busbar.
- Direct three-phase loads: motors, three-phase heat pumps, compressors, pumps, industrial tools.
- Installation head: 300 mA fire protection for the entire installation.
- Tertiary or industrial: where drives, inverters and electronic loads are omnipresent.
The RGIE sets a very clear framework regarding differential devices: as soon as a circuit powers electronic equipment – which is now the norm – the use of type A is mandatory. In new or renovated installations, type AC differentials are no longer permitted, which makes type A (and its reinforced, selective or adapted variations to particular loads) essential in 4 poles.
In Belgian practice, where three-phase panels are common and where electronic loads are multiplying, the4-pole differential switch has become the central building block of the protection architecture.
The Teconex range of 4-pole differential switches
The Teco range is one of the most readable and coherent on the Belgian market. It is based on three complementary families:
- “Standard” models (F9-40, F9-63, F9-80, F9-100)
- “Connectable” models (FB94)
- “Digital” models: DGA (Type A digital), DU (Type A variable frequency), GB (Type B), GBFQ (Type B variable frequency), DSA (Type A selective), S-B and S-BFQ (Type B selective)
All families of 4-pole differential switches have three important common characteristics:
- Type A systematic (RGIE compliant)
- Ratings 25 to 100 A
- Sensitivities 30 / 100 / 300 mA
“Standard” 4P differential switches
These are the models of4-pole differential switches used in 80% of professional installations: three-phase residential switchboard, classic tertiary sector, 300 mA installation head, light workshops, etc. They are robust, simple, perfectly suited to classic architecture and renovations.
Key Features:
- Type A (no 4P AC model in the Teco range)
- Ratings: 25, 40, 63, 80, 100 A
- Sensitivities: 30 / 100 / 300 mA
- S-A (selective) versions for upstream stages
- Very good resistance to unbalanced loads (frequent case in three-phase with mixed circuits)
| Reference | Kind | Caliber | Sensitivity | Use |
|---|---|---|---|---|
| F9404003A | Type A | 40A | 30mA | Protection of distributed single-phase groups (three-phase panels). |
| F9634003A | Type A | 63A | 30mA | More busy tertiary circuits, IT + lighting + sockets. |
| F980403A | Type A | 80A | 300mA | Three-phase installation head (fire protection). |
| F9100403A | Type A | 100A | 300mA | Heavy industrial or tertiary installations. |
| F963403SA | Type A Selective | 63A | 300mA | Selective upstream of stages 30 mA. |
“Connectable” 4P differential switches
This range contains 4-pole differential switches prepared to receive control modules (ASA/USA). These models are rarely offered by general manufacturers, although their usefulness on the Belgian ground is very real.
They are to be used when it is necessary:
- Remote control,
- Simple GTB integration,
- An automatic cut-off per scenario,
- Reset remotely or if security commands are required.
Unlike digital models, the connectable ones remain entirely mechanical: no LED display, no internal logic, which makes them very robust and easy to troubleshoot models.
Key Features:
- Type A
- Ratings 40 and 63 A
- Sensitivities 30 / 100 / 300 mA
- Compatible with ASA (remote triggering) and USA (minimum voltage) modules
| Reference | Kind | Caliber | Sensitivity | Use |
|---|---|---|---|---|
| FB9404003A | Type A | 40A | 30mA | Connectable 4P differential for GTB / single control. |
| FB9634003A | Type A | 63A | 30mA | Technical sites, telecoms, workshops. |
| FB940403A | Type A | 40A | 300mA | Fire protection + remote control possible. |
| FB963403A | Type A | 63A | 300mA | Tertiary with supervised circuits. |
4P “Digital” differential switches
These models of4-pole differential switches are intended for complex electronic chains and become essential in installations comprising drives, PV or IRVE inverters when a DC component is possible or even probable. Only Type B or S-B digital differentials guarantee correct detection of continuous or disturbed faults.
They offer:
- Better immunity to disturbances,
- Better detection precision,
- An LED display,
- Variable frequency versions, type B, selective S-A, selective S-B, etc.
Key Features:
- Type A / A Var.F / B / B Var.F / Selective S-A / Selective S-B
- Ratings 25 / 40 / 63 A
- Sensitivities 30 / 300 mA depending on type
| Reference | Kind | Caliber | Sensitivity | Use |
|---|---|---|---|---|
| F9404003DGA | Type A Digital | 40A | 30mA | Sensitive circuits, moderate electronic loads. |
| F9404003DU | Type A Var.F | 40A | 30mA | Light VFDs, pro LEDs, HF power supplies. |
| F9254003GB | Type B | 25A | 30mA | PV inverters, drives, IRVE. |
| F963403GB | Type B | 63A | 300mA | Upstream differential for installations with DC load. |
| F940403SB | Type S-B | 40A | 300mA | Selective upstream in PV/IRVE/variators environment. |
| F940403SBFQ | Type S-B Var.F | 40A | 300mA | Selective upstream + high frequency disturbances. |
These models ofdifferential switches are essential as soon as an installation includes drives, PV or IRVE inverters: only Type B or S-B digital differentials guarantee correct detection of continuous or disturbed faults.
How to choose a 4-pole differential switch?
The choice of a 4-pole differential switch never depends on a single criterion. Three parameters really govern the selection:
- The type of load (resistive, electronic, variators, PV, IRVE, etc.)
- The position in the architecture (installation head, sub-panel, sensitive circuit, etc.)
- The context of the installation (tertiary, industrial, technical, three-phase residential)
Installation head (300 mA — fire protection)
The 4-pole differential switch 300 mA must be as immune as possible, and less sensitive than the 30 mA stages. Here, the S-A or S-B models are recommended as soon as several downstream differentials exist.
| Use | Kind | Sensitivity | Caliber | Teco reference | For what ? |
|---|---|---|---|---|---|
| Three-phase domestic panel | Type A | 300mA | 40A | F940403A | Robust standard for installation head. |
| Tertiary sector / light workshop | Type A | 300mA | 63A | F963403A | Better supports cumulative leaks from electronic circuits. |
| Several downstream stages (selectivity) | Type S-A | 300mA | 63A | F963403SA | Built-in timer → downstream triggers first. |
| Installations with PV/IRVE/variators | Type S-B | 300mA | 40–63 A | F940403SB / F963403SB | Selectivity + DC/HF compatibility. |
| Disturbed environments (industries, HF) | Type S-B Var.F | 300mA | 40–63 A | F940403SBFQ / F963403SBFQ | Selectivity + wideband variators. |
Circuit groups (30 mA — personal protection)
These are the “mid-panel” 4-pole differential switches, before the circuits themselves. The choice depends above all on the rate of electronic charges behind each group.
| Use | Kind | Sensitivity | Caliber | Reference | For what ? |
|---|---|---|---|---|---|
| Classic mixed circuits | Type A | 30mA | 40A | F9404003A | Versatile three-phase standard (sockets + LED + IT). |
| Heavier groups (tertiary) | Type A | 30mA | 63A | F9634003A | Absorbs cumulative HF leaks (IT/LED). |
| LED of variable quality / IT grouped | Type A Var.F | 30mA | 40–63 A | F9404003DU / F9634003DU | Better immunity to switching power supplies. |
| Light variators, PAC Inverter | Type A Var.F | 30mA | 40A | F9404003DU | Increased stability with non-linear loads. |
| Drives, inverters, controlled motors | Type B | 30mA | 40A | F9404003GB | DC detection required with power electronics. |
| PV / IRVE inverters | Type B | 30mA | 25–40 A | F9254003GB / F9404003GB | Safety essential if DC smoothed possible. |
Heavy technical circuits (300 mA local)
Sometimes we place a local 4-pole differential switch 300 mA, only to protect a specific outlet (HVAC, extractor, three-phase pump, etc.).
| Use | Kind | Sensitivity | Caliber | Reference | For what ? |
|---|---|---|---|---|---|
| Three-phase technical departure (pump, HVAC) | Type A | 300mA | 40A | F940403A | Local fire prevention. |
| Highly electronic circuit | Type A Var.F | 300mA | 40–63 A | F940403DU / F963403DU | Less sensitive to parasitic HF signals. |
| Group of machines with variators | Type B | 300mA | 63A | F963403GB | Necessary if DC component possible. |
| Upstream of workshop with var. /PV | Type S-B | 300mA | 40–63 A | F940403SB / F963403SB | Selectivity + DC tolerance. |
Remote control (coupled + ASA/USA)
The range of 4-pole differential switches FB94 / FB963 is the only range in the Teco catalog and one of the few on the market that can be fully coupled to become controllable via ASA/USA.
| Use | Kind | Caliber | Sensitivity | Reference | Function |
|---|---|---|---|---|---|
| Simple GTB cutoff | Type A | 40A | 30mA | FB9404003A | Controllable via ASA/USA. |
| Telecom / IT / multi-site | Type A | 63A | 30mA | FB9634003A | Piloting + HF stability. |
| Controllable fire protection | Type A | 40–63 A | 300mA | FB940403A / FB963403A | Remote emergency shutdown. |
Why Teconex for your 4-pole differential switches?
The Belgian market is demanding: frequent three-phase installations, varied electronic loads, complex renovation, strict standards... The range of 4-pole differential switches Teco is precisely designed to meet these constraints, without unnecessary complexity:
- A readable and structured range: three families (Standard F9, Connectable FB94, Digital DGA/GB/SB/Var.F) cover the most common uses in three-phase residential, tertiary and light industry.
- Complete compatibility with Belgian needs: systematic type A, RGIE compliance, selective S-A / S-B versions, Var.F options for non-linear loads, B versions for PV/IRVE/variators. The range of 4-pole differential switches responds to all situations actually encountered in the field.
- Coherent modular logic: ASA/USA modules, auxiliary contacts, standardized and maintainable accessories. The installer is not locked into a proprietary architecture.
- Stable availability: the Teco range is based on a monitored and long-lasting catalog, a crucial point for tiered panels, technical networks and industrial installations.
- Experienced local support: Teconex teams master the requirements of the RGIE, Belgian three-phase configurations, DSO constraints and modern issues (PV, IRVE, drives, HVAC Inverter).
Need more advice? Check out our other articles:
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- An unrivaled 5-year warranty on your 4-pole differential switches
- Short channels for your 4-pole differential switches
- Teconex: the leader in 4-pole differential switch since 1932
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