Omron Relays & Safety Switches
Omron industrial control components stocked in India — G3NA solid state relays from 25 A to 90 A, and D4 series safety interlock switches for machine guarding. Industrypapa supplies both with a GST invoice and pan-India delivery.
G3NA solid state relays
The G3NA is Omron's surface-mounting single-pole SSR, and it is the part most people mean when they ask us for an Omron relay. It switches an AC load with no moving contacts, so there is nothing to arc, pit or wear out — which is why it is used where a contactor would be replaced every few months: heater control on extruders and ovens, packaging sealing jaws, and anywhere the load cycles constantly.
All the units we stock are zero-crossing types with a DC control input, so they switch as the AC waveform passes through zero. That keeps electrical noise down, which matters when the same panel holds sensors and a PLC.
| Part number | Rated current | Notes |
|---|---|---|
| G3NA-225B-UTU DC5-24 | 25 A | 24–240 VAC output, zero crossing, LED indicator |
| G3NA-240B-UTU DC5-24 | 40 A | 24–240 VAC output |
| G3NA-250B-UTU DC5-24 | 50 A | 24–240 VAC output |
| G3NA-275B-UTU-2 DC5-24 | 75 A | Higher current version |
| G3NA-290B-UTU-2 DC5-24 | 90 A | The largest in the range we hold |
| G3NA-425B-UTU-2 DC5-24 | 25 A | 440 V class |
| G3NA-440B-UTU-2 DC5-24 | 40 A | 440 V class |
| G3NA-450B-UTU-2 DC5-24 | 50 A | 440 V class |
The code reads simply: the first digit after G3NA is the output voltage class — 2 for the 240 V range and 4 for the 440 V range — and the next two digits are the rated current in amps. DC5-24 is the control input range. Confirm the load current and voltage with us before ordering; SSRs are sized on the actual load, not the nameplate of the machine.
D4 safety interlock switches
D4BL-2DRG
Solenoid interlock switch — the guard stays locked until the machine has come to a safe state, rather than simply signalling that it has been opened.
D4NL-4CFA-B
D4NL series guard lock safety door switch for machine guarding on access doors and gates.
Sizing a solid state relay
- Derate generously. An SSR run near its rating gets hot; most failures we see are thermal.
- Fit a heatsink. Above about 10 A a heatsink is not optional, and the panel needs airflow.
- Check the load type. Resistive heaters are the easy case; motors and transformers draw a large inrush.
- Match the control voltage — these are DC input units, typically driven straight from a PLC output.
- Zero-crossing or random. Zero-crossing for heaters and general switching; random phase is for dimming and phase control.
- Protect it. A semiconductor fuse protects the SSR; a standard fuse usually does not act fast enough.
Buying Omron components in India
Industrypapa supplies Omron relays and safety switches to machine builders, packaging and pharma plants and maintenance teams across India. Tell us the load — what you are switching, at what current and voltage — and we will confirm the right code rather than simply quoting the one you asked for. GST invoice, pan-India delivery.
Related ranges: limit switches, power supplies, temperature controllers, inductive proximity sensors and photoelectric sensors. For anything not listed, send us the part number.
Frequently asked questions
What is a solid state relay?
A relay with no moving parts. A small DC signal switches an AC load through semiconductors, so there are no contacts to arc or wear. It suits high cycling rates where a mechanical contactor would fail quickly.
Does a G3NA need a heatsink?
Above roughly 10 A, yes, and the panel needs airflow. Heat is the main cause of SSR failure, so allow generous derating on the current rating.
What does zero-crossing mean?
The relay waits for the AC waveform to pass through zero volts before switching. That reduces the electrical noise thrown into the panel, which matters when sensors and a PLC share the enclosure.
Can I use these to switch a motor?
Only with care. Motors and transformers draw a heavy inrush, so the SSR has to be sized well above the running current. Tell us the load and we will size it properly.
