
Selec RSS-TD1A140ZP DC Input AC Output Solid State Relay – 40A
Selec RSS-TD1A140ZP Solid State Relay – 40A, 24–330VAC, DC Control (4–32VDC), Zero-Cross
Heavy-duty panel-mount SSR with 40A switching capacity, 24–330VAC load voltage, 4–32VDC control input, zero-cross switching, IP20 touch-safe cover, and LED status indicator. Ideal for heaters, motors, ovens, and industrial automation panels.
The Selec RSS-TD1A140ZP is a 40A single-phase solid-state relay designed for high-reliability switching of AC loads using a DC control signal. With zero-cross firing, high surge capability, an IP20 protective cover, and built-in LED input indication, it is ideal for industrial heater loads, resistive loads, and general automation applications.
KEY FEATURES
Rated load current: 40A
Load voltage: 24–330 VAC
Control input: 4–32 VDC
Zero-cross switching
LED input state indication
IP20 touch-safe removable cover
Industrial-grade surge capability
Reverse voltage protection
Cost-effective & reliable panel-mount SSR
TECHNICAL SPECIFICATIONS
Input Specifications
| Parameter | Value |
|---|---|
| Control Voltage Range | 4–32 VDC |
| Control Current | 4–15 mA |
| Nominal Input Impedance | 2 kΩ |
| Pickup Voltage | 3 VDC |
| Dropout Voltage | 1 VDC |
| Max Reverse Voltage | 40 VDC |
| Response Time (ON) | ½ cycle + 1 sec |
| Response Time (OFF) | ½ cycle + 1 sec |
| Zero-Cross Turn-On | Available |
| Reverse Voltage Protection | Available |
| LED Indicator | Available |
Output Specifications
| Parameter | Value |
|---|---|
| Maximum Load Current | 40A |
| Minimum Load Current | 50 mA |
| Load Voltage Range | 24–330 VAC |
| Transient Voltage | 800 Vpk |
| Off-State Leakage | 10 mA |
| On-State Voltage Drop | 1.5V |
| dv/dt Rating | 1000 V/µsec |
| Surge Current (1 sec @ 50 Hz) | 150 Apk |
| 1-Cycle Surge Current | 400 Arms |
| Thermal Resistance (RθJC) | 0.9°C/W |
| Minimum Required Heat Sink | 1°C/W (at 40°C ambient) |
General Specifications
| Parameter | Value |
|---|---|
| Dielectric Strength (Input/Output → Ground) | 4000 Vrms |
| Dielectric Strength (Input ↔ Output) | 4000 Vrms |
| Insulation Resistance | 100 MΩ at 500 VDC |
| Max Input/Output Capacitance | 0.8 pF |
| Ambient Temperature (Operation) | −30°C to +80°C |
| Ambient Temperature (Storage) | −30°C to +100°C |
| Humidity | 93% RH (non-condensing) |
Housing & Mechanical
| Parameter | Value |
|---|---|
| Dimensions | 44.5 × 57.5 × 27.3 mm |
| Weight | 87.2 g |
| Baseplate | Aluminium |
| Housing Material | Glass-filled polyester |
| Mounting Type | Panel mount |
| LED Indicator | Red |
Wiring & Torque Specs
| Screw | Wire Size | Torque |
|---|---|---|
| M4 (Input) | 0.75–2.5 mm² | 1.2 N·m |
| M5 (Output) | 1.5–10 mm² | 2.0 N·m |
The wiring diagram on page 5 shows:
DC control input (± terminals)
AC load and AC line connections
APPLICATIONS
Plastic machine heaters
Industrial ovens & furnaces
HVAC heating systems
Resistive & inductive AC loads
Solenoid valves
Motor soft-start switching
Temperature control loops (with PID controllers)
WHAT’S IN THE BOX
RSS-TD1A140ZP SSR
IP20 protective cover
Mounting screws
User documentation
FAQS
Q1. What load voltage does RSS-TD1A140ZP support?
24–330 VAC load range.
Q2. What is the control input voltage?
4–32V DC.
Q3. Does it have zero-cross switching?
Yes—RSS-TD1A140ZP is a zero-cross SSR.
Q4. Is a heat sink required?
Yes—a minimum 1°C/W heat sink is required at 40°C.
Q5. Is the SSR suitable for inductive loads?
Yes—ZP models handle resistive loads; L-suffix models handle inductive loads.
(RSS-TD1A140ZP is resistive type.)
Q6. What is the surge current capability?
150A (1-second peak), 400A (1-cycle peak).