FOTEK SSR-75DA Solid State Relay

Description

The Fotek SSR-75DA is an industrial-grade single-phase solid state relay engineered for high-duty-cycle, contactless power modulation. Utilizing optical isolation between the low-voltage control input and high-voltage power output, the unit incorporates zero-crossing trigger architecture to eliminate electrical noise (EMI/RFI) and transient voltage spikes during AC load switching. Built on a heavy-duty aluminum heat-transfer baseplate and housed in a flame-retardant PBT enclosure, this component delivers extended lifecycle performance over electromechanical contactors in continuous production environments.

Technical Specifications:
Control Input Voltage: 4 to 32 VDC
Control Input Current: 6 to 25 mA DC
Turn-On Voltage: 4 VDC
Turn-Off Voltage: 1 VDC
Rated Load Current: 75 A AC (RMS)
Rated Load Voltage: 24 to 380 VAC
Peak Blocking Voltage: 600 VAC (Vp)
Switching Method: Zero-Cross Trigger (Zero Voltage Turn-On)
Peak One-Cycle Surge Current: 750 A (10 ms at 50/60 Hz)
On-State Voltage Drop: ≤ 1.6 VAC at rated current
Off-State Leakage Current: ≤ 5 mA at 220 VAC
Response Time (Turn-On): ≤ 10 ms (1/2 cycle)
Response Time (Turn-Off): ≤ 10 ms (1/2 cycle)
Dielectric Strength (Input-Output-Base): ≥ 2500 VAC (1 minute)
Insulation Resistance: ≥ 50 MΩ at 500 VDC
Operating Temperature Range: -20 °C to +80 °C
Baseplate Material: High-conductivity Aluminum
Housing Material: Flame-retardant PBT (UL 94V-0 compliant)
Terminal Configuration: Heavy-duty screw clamp with touch-safe transparent cover
Mounting Configuration: Panel / Heatsink surface mount via dual M4/M5 fixing holes
Dimensions (L x W x H): 58.0 mm x 45.0 mm x 32.0 mm
Weight: 105 g
Certifications and Standards: CE, RoHS, ISO9001

System Integration and Thermal Dynamics:
The SSR-75DA provides direct Technical Compatibility with digital automation systems, programmable logic controllers (PLCs), PID temperature controllers, and standard TTL/CMOS logic circuits without requiring interposing relays. For operational currents exceeding 10 A, integration with an appropriately rated extruded aluminum heatsink and thermal interface material (thermal paste or phase-change pad) is mandatory to maintain baseplate temperatures below 70 °C. For inductive load management, an external varistor (MOV) across output terminals 1 and 2 is recommended to safeguard the internal thyristors against AC line surges.

Industrial Application Profile:
The SSR-75DA is designed for multi-zone PID temperature regulation in industrial plastic extrusion lines, blow molding machinery, reflow ovens, and electric heat treatment furnaces. In these environments, rapid cycling of high-wattage resistive heating elements rapidly degrades mechanical contactors through contact welding and arcing. The zero-crossing switching profile of the SSR-75DA eliminates contact wear, suppresses transient electrical noise on the plant bus, and maintains precise thermal equilibrium in mission-critical manufacturing processes.

Procurement and Lifecycle Support:
Manufactured to Original Engineering specifications, the Fotek SSR-75DA guarantees drop-in field replacement and consistent electrical characteristics across modular automation panels. Structured supply chain management supports reliable Lead Time schedules for planned equipment builds and critical MRO operational reserves.

Key Attributes
Brand Name: FOTEK
Model Number: SSR-75DA
Type: Single-phase
Relay Type: Single-phase
Mounting Type: Screw
Place of Origin: Taiwan, China
Description: -
Application: Load heating
Output Type: Exchange
Coil Type: DC control AC
Circuit: -
Connector Type: -
Voltage - Output: 24~380VAC
Contact Rating (Current): 75A
Voltage - Input: 4~32VDC
Switching Voltage: <3.5VDC
Current - Input: -
Contact Form: -
Voltage - Load: -
On-State Resistance (Max): -
Current - Output: -
Termination Style: -
Load Current: -
Coil Current: -
Coil Voltage: -
Series: SSR-DA
Features: -
Model: SSR-75DA
Rated current: 75A
I²t for fuse: 1328A²S
Surge current: 820A
Peak voltage: 1200VAC min.
Output voltage: 24~380VAC
Lnput voltage: 4~32VDC
Turn off voltage: <3.5VDC

Packaging and Delivery
Selling Units: Single item
Single package size: 6.1X4.5X3 cm
Single gross weight: 0.100 kg