Selec RSS-SD1A2125ZPL DC Input AC Output 125A Solid State Relay
Selec RSS-SD1A2125ZPL Solid State Relay – 125A, 48–480VAC, DC Control, Zero-Cross, Inductive-Load Type
High-capacity 125A SSR with DC control (4–32 VDC), 48–480 VAC load voltage, zero-cross switching, inductive-load compatibility, 1600 V transient protection, IP20 touch-safe cover, and LED ON indication.
Selec RSS-SD1A2125ZPL is a 125A heavy-duty solid-state relay designed for inductive and resistive AC loads. It supports 48–480 VAC output, 4–32 VDC control input, zero-cross turn-on, and high surge immunity and comes with a touch-safe IP20 cover and LED ON indicator. Suitable for industrial heaters, solenoids, motors, and high-inrush loads.
KEY FEATURES
Rated load current: 125A
Load voltage: 48–480 VAC
Control voltage: 4–32 VDC
Zero-cross switching (ZP)
Inductive-load optimized (L-type)
Transient protection: 1600 Vpk
LED input status indicator
IP20 touch-safe removable cover
Back-to-back SCR output design (series SOP)
Cost-effective industrial switching solution
TECHNICAL SPECIFICATIONS
Input Specifications
| Parameter | Value |
|---|---|
| Control Voltage Range | 4–32 VDC |
| Control Current | 4–15 mA |
| Pickup Voltage | 3 VDC |
| Dropout Voltage | 1 VDC |
| Input Impedance | 2 kΩ |
| Max Reverse Voltage | 40 VDC |
| Zero-Cross Turn-On | Yes |
| LED Indicator | Yes |
| Reverse Voltage Protection | Yes |
| Response Time | ½ cycle + 1 msec (ON & OFF) |
Output Specifications
| Parameter | Value |
|---|---|
| Max Load Current | 125A |
| Load Voltage (Min–Max) | 48–480 VAC |
| Minimum Load Current | 0.1 A |
| Transient Voltage | 1600 Vpk |
| Off-State Leakage | 20 mA |
| On-State Voltage Drop | 1.6 V |
| dv/dt | 1000 V/μsec |
| 1-Cycle Surge Current | 2000 Arms |
| I²t (½ cycle) | 11250 (min) / 20000 (typical) |
| Thermal Resistance (RθJC) | 0.45 °C/W |
| Minimum Required Heat Sink | 0.1 °C/W |
General Specifications
| Parameter | Value |
|---|---|
| Dielectric Strength (I/O ↔ Ground) | 4000 Vrms |
| Dielectric Strength (Input ↔ Output) | 4000 Vrms |
| Minimum Insulation Resistance | 100 MΩ (500 VDC) |
| Capacitance (I/O) | 0.8 pF |
| Operating Temp | −30°C to +80°C |
| Storage Temp | −30°C to +100°C |
| Ambient Humidity | 93% RH (non-condensing) |
Housing/Mechanical
| Parameter | Value |
|---|---|
| Dimensions | 58.50 × 46.75 × 41 mm |
| Weight | 145 g |
| Baseplate | Aluminium |
| Material | Glass-filled polyester |
| Mounting Type | Panel Mount |
| LED Indicator | Red |
Wiring & Tightening Torque
| Terminal | Wire Size | Torque |
|---|---|---|
| M4 Input Terminals | 0.75–2.5 mm² (18–14 AWG) | 1.2 N·m |
| M6 Load Terminals | 1.5–10 mm² (16–8 AWG) | 2.5 N·m |
The wiring diagram on page 4 clearly shows:
DC input (±)
AC output terminals connected inline with the load
APPLICATIONS
Industrial heaters (high kW)
Solenoids & inductive coils (L-type SSR)
Motor soft-switching (low HP AC motors)
Ovens, dryers, plastic machines
High-inrush loads
Packaging and sealing machinery
WHAT’S IN THE BOX
Selec RSS-SD1A2125ZPL SSR
IP20 protective cover
Mounting screws
User manual
FAQS
Q1. What is the load current rating?
125A continuous (with sufficient heat sink).
Q2. Is RSS-SD1A2125ZPL inductive-load compatible?
Yes—the suffix “L” = inductive & resistive load support.
Q3. What load voltage range can it switch?
48–480 VAC.
Q4. What type of switching does it use?
Zero-cross (ZP).
Q5. Is a heat sink required?
Yes—minimum 0.1°C/W at 40°C ambient.
Q6. Does it have LED indication?
Yes—a red LED indicates the ON state.