Bus Systems and Digital Data Protection
The Raycap RayDat digital system protection family is a series of SPDs developed for the protection of industrial bus systems and LAN networks against lightning-induced surges. It offers specialized models for Ethernet, CAN, Profibus, RS485, RS232, and KNX protocols. Key features include Cat 6 compatibility, PoE (IEEE 802.3af/at/bt) compliant models, various shielding options, and uninterrupted line connection during module replacement.
Bus systems are an indispensable component of today's industrial applications. They transmit commands to actuators and relay signals from sensors to data centers and controllers. The most common bus systems are Ethernet, CAN, Profibus, RS485, RS232, and KNX, all of which require surge protection for optimal performance.
The fundamental vulnerability of these lines lies in long cable distances — long cables act like antennas against atmospheric disturbances. Switching transients within buildings and electrostatic discharges also pose a separate risk.
Product Families:
RayDat NET 6 POE — for LAN network protection. Protects all four lines in UTP and STP cables, is Cat 6 compliant, and offers a 250 MHz cutoff frequency. Suitable for 1 Gbit/s lines and fully compatible with all PoE versions (IEEE 802.3af, 802.3at, 802.3bt). Provides ground potential equalization between the signal and the protective network or PC chassis ground. Metal housing, RJ45 input/output sockets, DIN rail mounting.
RayDat SBH-3 Series — for industrial fieldbus systems (CAN Bus, Profibus DP, RS 232/V.24, RS 485, Sinec L2). Specifically designed for sites with high ground potential rise, such as near electric railways.
RayDat SGH-3 Series — for systems requiring separated signal ground, especially RS 232. Wide voltage range from 5 V to 110 V.
RayDat RS 485 — designed for all versions of RS 485; also usable with RS 422 and V.11 protocols. Protects 2 pairs (4 conductors), offers 20 kA discharge capacity.
RayDat KNX — for KNX systems. Thanks to its special design, it is mounted directly on bus terminals — no separate DIN rail space required. Weighs only 8 g.
Technical approach: Devices feature a multi-stage structure — coarse protection is provided by a three-pole gas discharge tube (GDT), fine protection by a high-speed silicon stage. This structure provides both common mode (longitudinal) — from each line to protective earth — and differential mode (transverse) — between pairs — protection. Coordination between stages ensures no voltage or impulse current "blind spots" occur. Thermal protection reduces the risk of thermal runaway in case of mains incursion faults.
Products comply with IEC/EN 61643-21 and UL 497B 4th Edition standards; many are UL Listed. Classification: D1 / C1 / C2 / C3.
Common Features
- Very high impulse current ratings
- Screw or quick-connect (spring) terminals
- Various shield-handling options
- Connection lines remain active during module replacement
- Cat 6 compatibility and PoE compliant models
- Multi-stage hybrid protection: GDT (coarse) + fast silicon (fine)
- Common mode (longitudinal) + differential mode (transverse) protection
- Energy coordination between stages — no blind spots
- Thermal protection — against mains incursion faults
- 35 mm DIN rail mounting (IEC/EN 60715)
- Protection class: IP 20 (embedded)
- Housing: gray thermoplastic, V-0 flame resistance (NET 6 POE: metal)
- Operating temperature: -40 °C … +80 °C
- Classification: D1 / C1 / C2 / C3
- Standards: IEC/EN 61643-21, UL 497B 4th Edition
RayDat NET 6 POE (LAN / Ethernet — UL Listed)
| NET 6 POE 48 | |
|---|---|
| Number of protected pairs | 4 pairs (8 conductors) |
| Nominal operating voltage Un | 48 V DC |
| Max. continuous operating voltage (line-line / pair-pair) Uc | 50 V / 72 V |
| Nominal load current IL (25 °C) | 1 A |
| In (8/20 µs) line-line | 150 A |
| C2 total discharge current (lines-ground) In | 10 kA |
| Iimp (10/350 µs) | 1 kA |
| Protection level Up (line-line / line-ground) | 150 V / 550 V |
| Response time tA | < 1 ns |
| Cutoff frequency fG | 250 MHz |
| Compatibility | Cat 6, 1 Gbit/s, PoE / PoE+ / PoE++ (802.3af/at/bt) |
| Connection | RJ45 input/output sockets |
| Housing | Metal, IP 20 |
| Dimensions / Weight | 19 mm / 120 g |
| Order code | 706 312 |
RayDat SBH-3 Series (industrial fieldbus — UL Listed)
| 5 | 12 | 30 | |
|---|---|---|---|
| Protected line | 1 pair (2 conductors) | ||
| Nominal operating voltage Un | 5 V | 12 V | 30 V |
| Max. continuous operating voltage Uc | 6 V | 15 V | 33 V |
| Nominal load current IL (25 °C) | 1 A | ||
| In (8/20 µs) | 10 kA | ||
| Imax (8/20 µs) | 20 kA | ||
| Iimp (10/350 µs) | 2.5 kA | ||
| Residual voltage @5 kA (line-line) Ures | < 22 V | < 42 V | < 80 V |
| Response time tA (line-line / line-ground) | < 1 ns / < 100 ns | ||
| Transverse capacitance (line-line / line-ground) | 50 pF / 5 pF | ||
| Cutoff frequency fG | 30 MHz | ||
| Dimensions / Weight | 12 mm (2/3 TE) / 60 g | ||
| Order code | 7082.86 | 7082.88 | 7082.90 |
| Quick connection (Q) | 7085.21 | 7085.22 | 7085.23 |
RayDat SGH-3 Series (separated signal ground — RS 232)
| 5 | 12 | 15 | 24 | 30 | 48 | 60 | |
|---|---|---|---|---|---|---|---|
| Nominal operating voltage Un | 5 V | 12 V | 15 V | 24 V | 30 V | 48 V | 60 V |
| Max. continuous operating voltage Uc | 6 V | 15 V | 18 V | 28 V | 33 V | 52 V | 64 V |
| In / Imax (8/20 µs) | 10 kA / 20 kA | ||||||
| Iimp (10/350 µs) | 2.5 kA | ||||||
| Residual voltage @5 kA Ures | < 22 V | < 42 V | < 48 V | < 70 V | < 80 V | < 140 V | < 160 V |
| Cutoff frequency fG | 30 MHz | ||||||
| Order code | 7086.61 | 7086.62 | 7086.63 | 7086.64 | 7086.65 | 7086.66 | 7086.67 |
110 V version also available
RayDat RS 485 (RS 485 / RS 422 / V.11)
| RS 485 | |
|---|---|
| Number of protected pairs | 2 pairs (4 conductors) |
| Nominal operating voltage Un | 5 V DC |
| Max. continuous operating voltage Uc | 6 V DC |
| Nominal load current IL (25 °C) | 500 mA |
| In (8/20 µs) line-line | 20 kA |
| Iimp (10/350 µs) | 2.5 kA |
| Residual voltage @5 kA (line-line) Ures | 20 V |
| Response time tA | < 1 ns |
| Thermal protection | Yes |
| Series resistance per path R | 1.7 – 1.9 Ω |
| Transverse capacitance C | < 2 nF |
| Cutoff frequency fG | > 1 MHz |
| Terminal cross-section | 2 × 2.5 mm² |
| Dimensions / Weight | DIN 43880 2 TE / 114 g |
| Order code | 703 812 |
RayDat KNX (KNX bus — terminal mounted)
| RayDat KNX | |
|---|---|
| Number of protected pairs | 1 pair (2 conductors) |
| Nominal operating voltage Un | 24 V AC |
| Max. continuous operating voltage Uc | 170 V DC |
| Nominal load current IL (25 °C) | 7 A |
| In (8/20 µs) | 5 kA |
| Imax (8/20 µs) | 10 kA |
| Iimp (10/350 µs) | 1 kA |
| Residual voltage @5 kA (line-ground / line-line) Ures | < 600 V / < 1000 V |
| Response time tA | < 100 ns |
| Insulation resistance Riso | ≥ 1 GΩ |
| Series resistance per path R | < 0.1 Ω |
| Cutoff frequency fG | 50 MHz |
| Mounting | Directly on bus terminal |
| Connection cable | 0.5 mm² line / 0.75 mm² ground, 200 mm |
| Weight | 8 g |
The RayDat digital system protection family is used in industrial communication and network infrastructures:
- Ethernet / LAN networks — Cat 6, 1 Gbit/s lines (NET 6 POE)
- PoE devices — IP camera, wireless access point, IP phone (802.3af/at/bt)
- Profibus DP lines — Industrial fieldbus systems (SBH-3)
- CAN Bus systems — Automation and in-vehicle communication (SBH-3)
- RS 485 / RS 422 / V.11 lines — Modbus RTU and serial communication (RS 485)
- RS 232 / V.24 connections — Systems requiring separated signal ground (SGH-3)
- KNX building automation — Direct bus terminal mounting (KNX)
- Sinec L2 networks — Siemens industrial communication (SBH-3)
- PLC and controller communication ports — Control system side
- Installations near electric railways — High ground potential rise (SBH-3)
- Long cable routes — Lines with high induction risk due to antenna effect
- In-building switching transients — Environments with electrostatic discharge risk
- Data center entry points — Network lines coming from outside the building
- Facilities requiring continuous operation — Line remains active during module replacement
