803 ZDA 48 25 01, Unison SSR Dc to Ac, 25amp

Product Description

The Unison 803 ZDA 48 25 01 is a 25 Amp DC to AC Slim Solid State Relay (SSR) designed for high-performance switching in industrial automation and control panels where installation space is limited. With its 23.6 mm slim body, this SSR occupies significantly less panel space while delivering the same reliable switching performance as conventional solid state relays. It features Zero Cross Switching, which turns the output ON only when the AC waveform crosses zero voltage, reducing electrical noise, minimizing inrush current, and extending the life of connected equipment.

The relay accepts a 4–32 VDC control input and switches 24–480 VAC loads up to 25 Amps, making it suitable for PLCs, PID temperature controllers, microcontrollers, and industrial automation systems. Built using Direct Bonded Copper (DBC) technology, the relay offers superior heat dissipation, improved thermal performance, and enhanced reliability during continuous operation. The optically isolated input and output provide additional protection for sensitive control circuits, while the built-in surge protection improves durability in electrically noisy industrial environments.

The 803 ZDA 48 25 01 is widely used in industrial heating systems, packaging machinery, textile equipment, plastic processing machines, food processing equipment, and process automation panels. Its DIN rail compatible slim heat sink arrangement makes installation easier in compact electrical panels where space optimization is important.

For optimum performance at rated current, an appropriately sized heat sink should always be used.

Key Features

• Model: 803 ZDA 48 25 01
• Brand: Unison
• DC to AC Slim Solid State Relay
• Rated Load Current: 25 Amp
• Zero Cross Switching
• Slim 23.6 mm wide design
• Input: 4–32 VDC
• Output: 24–480 VAC
• Optically isolated input and output
• Built-in surge voltage protection
• LED input indication
• Long electrical life (up to 10¹¹ switching cycles)
• Compact DIN rail/panel mounting

Technical Specifications

Applications

The Unison 803 ZDA 48 25 01 is suitable for:

• Temperature control using PID controller
• Resistance heater switching
• Motor starting
• UV lamp control
• Plastic welding machines
• Industrial ovens and furnaces
• Packaging and sealing machines
• Textile machinery
• Food processing equipment
• Industrial automation control panels

Why Buy from Voltkart?

• Genuine Unison Solid State Relays
• GST Invoice provided
• Pan India delivery
• Bulk pricing available for OEMs, panel builders and machine manufacturers
• Expert technical support for product selection
• Trusted supplier of industrial automation components

Frequently Asked Questions

1. What makes the 803 series different from the standard 101 series SSR?

The 803 series features a slim 23.6 mm design, making it ideal for compact electrical panels while maintaining the same reliable industrial switching performance.

2. What control signal is required?

The relay operates with a 4–32 VDC control input, making it compatible with PLCs, PID controllers, and most industrial automation systems.

3. Is a heat sink required?

Yes. For continuous operation at the rated 25 Amp load, an appropriately sized heat sink is recommended to ensure efficient heat dissipation and longer service life

Related Products & Collections

Also explore our complete range of Protection Relays, Phase Failure Relays, Phase Sequence Relays, and Motor Protection Devices for enhanced electrical safety.

For complete automation panel solutions, browse our collections of PLCs, Timers, Temperature Controllers, AC Drives, and SELEC automation products. You may also be interested in our range of Power Supply solutions including DIN Mounted SMPS, Enclosed SMPS, 1 Phase SMPS, 3 Phase SMPS, and popular Mean Well MDR Series, NDR Series, EDR Series, and TDR Series power supplies for industrial applications.