Unison Solid State Relays (SSR)

Unison price list on Voltkart: 22 Unison products from ₹302 including GST. Voltkart is an authorised Unison distributor, with a GST invoice on every order and delivery across India.

Unison makes solid state relays (SSR), 3-phase SSRs and SCR power controllers for heater and process control panels. Prices checked 3 November 2026. Reviewed by Amit, Voltkart.

Unison price list (live prices)

Solid State Relays (SSR) (22)

Model	Price (incl. GST)
Unison 101 ZDA 48 25 01, SSR DC to AC, 25 Amp	₹302
Unison 901 ZDA 48 25 01 AL5, SSR DC to AC, 25 Amp	₹450
Unison 101 ZDA 60 40 01, SSR DC to AC, 40 Amp	₹454
Unison 803 ZDA 48 25 01, SSR DC to AC, 25 Amp	₹460
Unison 807 PMDD 100 08 01, SSR DC to DC, 8 Amp	₹510
Unison 807 ZDA 48 08 01, SSR DC to AC, 8 Amp	₹510
Unison 101 PMDD 200 15 00, SSR DC to DC 15 Amp	₹580
Unison 803 ZDA 48 40 01, SSR DC to AC, 40 Amp	₹595
Unison 901 ZDA 48 40 01 AL5, SSR DC to AC, 40 Amp	₹605
Unison 901 ZDA 60 50 01 AL5, SSR DC to AC, 50 Amp	₹860
Unison 803 ZDA 58 50 01, SSR DC to AC, 50 Amp	₹955
Unison 901 PHT 24 40 420 AL5, Scr, Input 4-20ma, output 240V AC, 40 Amp	₹1,195
Unison 901 ZDA 60 90 01 CU2, SSR DC to AC, 90 Amp (heat sink not included)	₹1,350
Unison 901 PHT 24 50 420 AL5, Scr, Input 4-20ma, output 240V AC, 50 Amp	₹1,355
Unison 905 3PH ZDA 48 25 01, 3 Phase SSR DC to AC, 25 Amp	₹1,433
Unison 803 ZDA 58 90 01, SSR DC to AC, 90 Amp	₹1,590
Unison 905 3PH ZDA 48 40 01, 3 Phase SSR DC to AC, 40 Amp (without heat sink base)	₹1,593
Unison 901 PHT 44 90 420 CU2, Scr, Input 4-20ma, output 440V AC, 90 Amp	₹2,150
Unison 901 PHT 24 90 420 CU2, Scr, Input 4-20ma, output 240V AC, 90 Amp	₹2,150
Unison 905 3PH ZUA 48 50 02, 3 Phase SSR DC to AC, 50 Amp	₹3,000
Unison 901 ZDA 60 200 01 CU2, SSR DC to AC, 200 Amp	₹3,110
Unison 905 3PH ZUA 48 90 02, 3 Phase SSR DC to AC, 90 Amp	₹4,200

Need an Unison part that is not listed, or a bulk price for several items? Send the part numbers on WhatsApp at 8800754881 (Mon–Sat, 12:30–7 pm) and we will quote the whole list with GST.

Which Unison SSR do I need?

Type (code)	Control signal	Switches	Typical use
DC to AC (ZDA)	DC from a controller's SSR output	Single-phase AC load	Heaters in ovens, moulding and sealing machines
3-phase DC to AC (905 3PH)	DC from a controller's SSR output	Three-phase AC load	Three-phase heater banks
DC to DC (PMDD)	DC signal	DC load	DC solenoids, valves and DC heaters
SCR power controller (PHT)	4–20 mA from a PID controller	AC load, proportional power	Smooth heater power control instead of on/off switching

Choose an SSR rated well above the load current: for a resistive heater, about 1.5 to 2 times the heater current is a common margin. SSRs get hot in use, so mount them on a heat sink (for example the G-68 DIN-rail heat sink, up to 26 A) or on the panel back-plate with thermal paste. For a ready-matched set, see the heater control kits (controller + Unison SSR + heat sink + sensor). Compare all solid state relays and temperature controllers.

Unison FAQs

What is the difference between a DC to AC and a DC to DC SSR?

Both are switched by a DC control signal. A DC to AC SSR (Unison ZDA models) switches an AC load such as a heater; a DC to DC SSR (Unison PMDD models) switches a DC load such as a solenoid or valve. Using a DC to AC SSR on a DC load will not switch off correctly.

How do I choose the SSR current rating?

Work out the load current (for a heater, watts divided by volts) and choose an SSR rated well above it, commonly 1.5 to 2 times the load current for resistive heaters, and always fit it on a heat sink.

When should I use an SCR power controller instead of an SSR?

Use an SCR power controller (Unison PHT, 4–20 mA input) when a PID controller should vary the heater power proportionally. An SSR only switches the load fully on or off, which is fine for most temperature control loops.