01 / 06 · Heat sink
It starts with where the heat goes.
Extruded aluminium heat sinks on a 35 mm DIN rail. Every relay ships with a published load table at 40 °C, from the C-56 up to the fan-cooled A-190.
- 35 mm DIN rail
- C-56 → A-190
Solid state relays · Ahmedabad · since 1992
Switch 200 amps.
Move nothing.
Unison solid state relays have no contacts to arc, bounce or wear. Designed, built and tested in India for heaters, motors and DC loads.
1992
Incorporated in Ahmedabad
200 A
Highest single-relay rating
157
Catalogue variants
40,000 sq ft
Manufacturing floor
Selector · Four questions
Tell us the load. Get the part number.
Results update as you answer, with the heat sink sized from Unison's published load tables at 40 °C.
09matches · 20 A · 230 VAC · 4–32 VDC
- BEST MATCH
Model 803 · Zero cross
Slim Zero Cross DC to AC SSR, 25 A
UNI 803 ZDA 48 25 01
- Rating
- 25 A · 480 V
- Heat sink
- B-24
- Load at 40 °C
- 20 A
- Zero-cross switching suits resistive heater loads
- UL approved
- 22.5 mm slim body
Model 901 · Zero cross
Zero Cross DC to AC SSR, 50 A
UNI 901 ZDA 60 50 01 AL5
- Rating
- 50 A · 600 V
- Heat sink
- G-68
- Load at 40 °C
- 26 A
- Zero-cross switching suits resistive heater loads
- UL approved
Model 803 · Zero cross
Fault Detection DC to AC SSR, 40 A
UNI 803 FDZDA 58 40 01
- Rating
- 40 A · 580 V
- Heat sink
- V-87
- Load at 40 °C
- 22 A
- Zero-cross switching suits resistive heater loads
- Detects open load, shorted load and shorted relay
- 22.5 mm slim body
Indicative selection from catalogue data. Heat-sink ratings assume 40 °C ambient and free air flow. Confirm inrush, duty cycle and ambient with Unison before ordering.
Switching lab · Try it
Four ways to switch a sine wave.
The right relay depends on when in the cycle it turns on. Pick a mode, drag the slider and watch what reaches the load.
Load voltage · 50 Hz
Waits 7.3 ms for the zero crossing
However late the control signal arrives, the relay holds off until the mains crosses zero. No sudden current step and very little electrical noise. The default for heaters.
Model 901 Zero Cross SSRRange · 52 product families
From a 2 A PCB relay to a 200 A power controller.
AHMEDABAD · PRODUCTION LINE
Make in India · One roof
Designed, assembled and load-tested in one plant.
Every stage, from PCB and mould design to SMT assembly and full-load testing, happens at Unison's facility in Ahmedabad.
- Two fully automatic high-speed SMT production lines
- Automatic conveyor lines for product assembly
- Dedicated R&D area for design and simulation
- QC and testing laboratory
- Semi-automatic packaging machines
- 40,000 square feet of floor area
ULCERoHSISO 9001ISO 14001
Technical capabilities Customers · In their words
Machine builders who have stayed for decades.
“We are affiliated with Unison since 1996, which was the beginning year for us too. This continuous connection is possible with constant technical upgradation and competitive pricing. Unison has developed a lot of customised and specialised solutions which are import substitutes.”
Have a load we have not listed?
Unison builds customised relays for OEMs. Send the load details and an engineer will reply with a part number.