Solid State Relays (SSR)

SSR price on Voltkart: single-phase solid state relays from ₹302 (25 A), three-phase from ₹1,433, and 4–20 mA SCR controllers from ₹1,195, including GST. Every model is in the table below.

A solid state relay (SSR) switches a load electronically with no moving contacts, so it is silent, fast and does not wear out like a contactor. SSRs mainly switch heaters in ovens, furnaces and plastic machinery from a temperature controller or PLC. Voltkart is an authorised distributor of Unison. Prices checked 6 October 2026. Reviewed by Amit, Voltkart.

SSR price list (incl. GST)

Model	Rating	Price
Single-phase SSR, DC input to AC output
Unison 101 ZDA 48 25 01	25 A	₹302
Unison 901 ZDA 48 25 01 AL5	25 A	₹450
Unison 803 ZDA 48 25 01	25 A	₹460
Unison 807 ZDA 48 08 01	8 A	₹510
Unison 101 ZDA 60 40 01	40 A	₹454
Unison 803 ZDA 48 40 01	40 A	₹595
Unison 901 ZDA 48 40 01 AL5	40 A	₹605
Unison 901 ZDA 60 50 01 AL5	50 A	₹860
Unison 803 ZDA 58 50 01	50 A	₹955
Unison 901 ZDA 60 90 01 CU2	90 A (heat sink not included)	₹1,350
Unison 803 ZDA 58 90 01	90 A	₹1,590
Unison 901 ZDA 60 200 01 CU2	200 A	₹3,110
Three-phase SSR, DC input to AC output
Unison 905 3PH ZDA 48 25 01	25 A	₹1,433
Unison 905 3PH ZDA 48 40 01	40 A (without heat sink base)	₹1,593
Unison 905 3PH ZUA 48 50 02	50 A	₹3,000
Unison 905 3PH ZUA 48 90 02	90 A	₹4,200
DC to DC SSR
Unison 807 PMDD 100 08 01	8 A	₹510
Unison 101 PMDD 200 15 00	15 A	₹580
SCR power controllers, 4–20 mA input
Unison 901 PHT 24 40 420 AL5	40 A, 240 V AC output	₹1,195
Unison 901 PHT 24 50 420 AL5	50 A, 240 V AC output	₹1,355
Unison 901 PHT 24 90 420 CU2	90 A, 240 V AC output	₹2,150
Unison 901 PHT 44 90 420 CU2	90 A, 440 V AC output	₹2,150
Heat sink
G-68 SSR heat sink	Up to 26 A, DIN rail mount	₹180

Click a model to open the product. The product page always shows the live price and stock.

How to choose an SSR

Load current: choose a rating well above the actual load, since capacity falls with temperature.
Heat sink: mount every loaded SSR on a heat sink; check whether one is included.
Control signal: DC input from a temperature controller's SSR output or a PLC, or 4–20 mA for SCR power controllers.
Phases and voltage: single-phase or three-phase, and the load voltage.

Learn more: solid state relays explained. Drive your SSR from a temperature controller with an SSR output.

Frequently asked questions

What is the price of a 25A SSR?

On Voltkart a single-phase 25 A SSR (DC input, AC output) costs from ₹302 (Unison 101 ZDA 48 25 01), including GST. A 40 A SSR starts at ₹454.

Does an SSR need a heat sink?

Yes. An SSR carrying real load current heats up and must be mounted on a heat sink sized for the current. The G-68 DIN-rail heat sink (₹180) suits loads up to 26 A. Some higher-current SSRs are sold without a heat sink, as noted in the table.

How much current rating should I choose?

Choose an SSR rated well above the actual load current, because SSR current capacity falls as the temperature rises. Many panel builders pick roughly double the load current, for example a 25 A SSR for a 10–12 A heater.

SSR or contactor for heaters?

An SSR switches silently with no moving contacts, so it suits frequent switching from a temperature controller's SSR output. A contactor suits infrequent switching and gives a visible air-gap isolation.

Is Voltkart an authorised Unison distributor?

Yes. Voltkart is an authorised distributor of Unison, with a GST invoice and pan-India delivery. See the Unison distributor page.

Not sure which model you need? Send the part number or your application on WhatsApp at 8800754881 (Mon–Sat, 12:30–7 pm) and we will help you choose. For bulk or OEM quantities, ask for a quote on the same number.