Electrical Relays Price Comparison
Compare 189 electrical relays from ABB, Schneider Electric, Siemens and more. Find the best price across top UK retailers, from 0 £ to 0 £.
Electrical Relays price comparison UK
Electrical relays sit at the heart of any serious control panel, yet they're one of those components where the wrong choice can bring an entire installation to its knees. Our catalogue covers 189 products spanning everything from compact DIN-rail modules to heavy-duty industrial switching units — and the price spread tells its own story. A basic Phoenix Contact signal relay can be had for 0 £, whilst a fully specified safety relay from ABB or Schneider Electric pushes well past 0 £. Knowing where your application sits on that spectrum is half the battle.
ABB dominates this category by sheer volume, with nearly 60 references and an average price that reflects their industrial-grade positioning. Phoenix Contact runs a close second — their PSR safety relay series is particularly well regarded in motor control and emergency-stop circuits. What's worth noting is how Schneider Electric manages to undercut both on average price whilst still covering the same functional ground; their A9C impulse relays, for instance, are a popular choice for lighting control in commercial buildings across the UK.
The technology split matters more here than in most categories. Electromechanical relays remain the workhorse of panel building — simple, proven, and easy to replace. But if your application involves high switching frequency or demands silent operation, a solid-state relay (SSR) is worth the premium. SSRs generate more heat (heatsinking is non-negotiable) but offer 10 to 100 million switching cycles against the 1–10 million typical of mechanical contacts. For low-power signal switching, reed relays offer a compact middle ground. Shelly's smart relay modules occupy a different niche entirely — Wi-Fi-connected and aimed squarely at home automation rather than industrial panels.
Mounting format is another practical consideration that often gets overlooked until it's too late. The vast majority of products here are designed for 35mm DIN rail installation, which suits standard distribution boards and control cabinets. PCB-mount variants are available for embedded designs, but they're a minority in this catalogue. If you're retrofitting an existing panel, double-check the form factor before comparing prices — a relay that doesn't fit your rail is no bargain at any price.
For UK buyers, it's worth confirming CE marking and IEC 61810 compliance, particularly for safety-critical applications. Retailers like RS Components, Farnell, and Screwfix stock many of these brands, but prices vary considerably between suppliers — which is precisely where comparing across merchants pays off. You can also explore related switching components such as electrical switches, electrical actuators, and automatic transfer switches to complete your control system.
How to Choose the Right Electrical Relay
With prices ranging from 0 £ to 0 £ and technology types that behave very differently under load, picking the wrong relay isn't just a waste of money — it can be a safety issue. Here's what actually matters, in order of importance.
Rated voltage and current for your circuit
This is the non-negotiable starting point. A relay rated for 24V DC coil activation won't work on a 230V AC control circuit, and a contact rating of 10A will fail — potentially dangerously — if you're switching a 16A motor load. Always check both the coil voltage (what activates the relay) and the contact rating (what the relay switches). Most industrial relays in this catalogue cover 24V DC or 230V AC coil options; contact ratings range from under 1A for signal relays up to 100A+ for power contactors. When in doubt, size up — a relay running at 80% of its contact rating will outlast one running at 100% by a significant margin.
Relay technology: electromechanical vs. solid-state
Electromechanical relays are the default choice for most panel-building applications — they're cheap, universally understood, and easy to replace in the field. Their weakness is mechanical wear: expect 1–10 million switching cycles before contacts degrade. Solid-state relays (SSRs) eliminate moving parts entirely, switching silently in microseconds and lasting 10–100 million cycles. The trade-off is heat: SSRs must be mounted on a heatsink, and they can fail 'closed' (conducting) rather than 'open', which has safety implications. For home automation or low-frequency switching, electromechanical wins on simplicity and cost. For high-cycle industrial processes, SSR is worth the extra spend — which typically starts around 0 £ in this catalogue.
Contact configuration (SPDT, DPDT, multi-pole)
SPDT (Single Pole Double Throw) is the most common configuration and handles the majority of on/off switching tasks. If you need to control two independent circuits simultaneously — or reverse motor polarity — you'll want DPDT or a multi-pole variant. Safety relay modules from Phoenix Contact and ABB often feature 3- or 4-pole configurations with forced-guided contacts, which are mandatory in EN ISO 13849-compliant safety circuits. Don't pay for poles you don't need, but don't underspecify either: retrofitting a DPDT where you installed an SPDT means rewiring the panel.
Inductive load protection (arcing and back-EMF)
Switching motors, solenoids, or transformers generates back-EMF voltage spikes that can arc across relay contacts, causing erosion and — in worst cases — contact welding. If your load is inductive, look for relays with built-in suppression: a free-wheeling diode for DC circuits, or an RC snubber / varistor (MOV) for AC. Some ABB and Schneider Electric units include this protection as standard; others require an external suppressor wired in parallel with the load. Skipping this step is the single most common cause of premature relay failure in motor control applications.
Mounting format and panel compatibility
The overwhelming majority of products here mount on a standard 35mm DIN rail, which suits most UK distribution boards and industrial control cabinets. Check the width in module units (typically 17.5mm to 45mm wide) to ensure you have enough rail space. Plug-in socket relays offer the advantage of hot-swap replacement without rewiring — useful in production environments where downtime is costly. PCB-mount relays are a different category entirely and generally not interchangeable with DIN-rail types. If you're building a new panel, DIN rail is almost always the right answer.
Certification and safety compliance
For UK and European installations, CE marking and compliance with IEC 61810 (electromechanical relays) or IEC 62314 (solid-state relays) is the baseline. Safety relays used in machine guarding or emergency-stop circuits must additionally meet EN ISO 13849 or IEC 62061 requirements — this is where Phoenix Contact's PSR series and ABB's safety relay range justify their higher price points. RoHS compliance is standard across the major brands. If you're specifying for a client or a regulated environment, always verify the datasheet rather than relying on product listings alone.
- Entry-level and signal relays (From 0 £ to 0 £) : Compact signal relays, basic SPDT modules, and budget DIN-rail units from brands like Finder, Eaton, and lower-tier ABB references. Perfectly adequate for simple on/off switching in low-current circuits. Don't expect safety-rated contacts or built-in suppression at this price point.
- The practical sweet spot (From 0 £ to 0 £) : Where most panel builders spend their money. Covers solid electromechanical relays from Siemens, Legrand, and mid-range Schneider Electric units. Reliable contact ratings, DIN-rail mounting, and often CE-certified. Good balance of performance and cost for standard industrial and commercial applications.
- Monitoring and timer relays (From 0 £ to 0 £) : ABB and Schneider Electric monitoring relays (phase failure, voltage monitoring, current monitoring) sit firmly in this band, as do programmable timer relays and some solid-state units. These are specialist components — you pay for the added intelligence, not just the switching capability.
- Safety and high-specification relays (Over 0 £) : Phoenix Contact PSR safety relay modules, ABB safety relays, and multi-function industrial units. Mandatory for EN ISO 13849-compliant safety circuits. The price reflects forced-guided contacts, dual-channel monitoring, and the certification overhead. Not overkill — genuinely necessary for the applications they're designed for.
Top products
- Hager ESC225 electrical relay (Hager) : The most-listed relay in the catalogue and genuinely good value for a DIN-rail impulse relay. Solid build quality typical of Hager's panel range, but verify the coil voltage matches your installation before ordering — it's a common source of returns.
- Phoenix Contact PSR-SCP- 24UC/ESAM4/3X1/1X2/B electrical relay Green, Yellow (Phoenix Contact) : A proper safety relay with forced-guided contacts and dual-channel monitoring — exactly what EN ISO 13849 Category 3/4 circuits demand. Expensive, but non-negotiable for emergency-stop applications. Overkill (and overpriced) for anything outside a safety function.
- Schneider Electric A9C30112 (Schneider Electric) : An impulse (bistable) relay from Schneider's Acti9 range — the go-to choice for centralised lighting control in commercial buildings. Reliable, well-documented, and available from multiple UK suppliers. Not a general-purpose relay; if you need standard on/off switching, look elsewhere.
- Shelly Plus i4 DC electrical relay Orange (Shelly) : A smart 4-channel input module for home automation — Wi-Fi connected, compact, and genuinely useful for integrating dry contacts into a smart home system. Not an industrial relay in any meaningful sense; don't specify it for panel building or safety circuits.
- ABB CT-ERS.22S electrical relay (ABB) : A star-delta timer relay from ABB's CT range — well-suited to motor starting applications where you need a controlled transition from star to delta winding. Precise timing, robust construction, and a datasheet you can actually trust. Niche use case, but excellent at what it does.
Related categories
Frequently Asked Questions
What is the difference between a relay and a contactor?
A relay is designed for low-to-medium current switching (typically under 25A) and control circuit applications, whilst a contactor is a heavy-duty switching device built for high-current power circuits — motor starters, for instance. In practice, the line blurs: some relays in this catalogue handle currents that overlap with small contactors. The key distinction is that contactors are built for continuous high-current duty with arc-quenching chambers, whereas relays prioritise signal isolation and control flexibility. If you're switching anything above 25A continuously, you almost certainly want a contactor rather than a relay.
Can I use a 24V DC relay on a 12V DC circuit?
No — a relay rated for a 24V DC coil will not reliably activate on 12V DC, as the coil requires its rated voltage to generate sufficient magnetic force to pull in the contacts. Running a 24V coil on 12V may result in chattering, partial engagement, or complete failure to switch. Always match the coil voltage exactly to your control circuit voltage. Most manufacturers offer the same relay model in multiple coil voltage variants (12V, 24V, 48V DC; 110V, 230V AC), so finding the right version is rarely a problem — just check the part number suffix carefully.
Are solid-state relays worth the extra cost for home automation?
For most home automation use cases, no — a standard electromechanical relay is sufficient and considerably cheaper. SSRs shine in high-frequency switching applications (thousands of cycles per day) or where silent operation is critical. A typical smart home relay switching lights or heating a few dozen times daily will last decades in electromechanical form. The exception is if you're switching resistive loads like heating elements at high frequency, where SSRs genuinely extend service life. Shelly's smart relay modules, which appear in this catalogue from around 0 £, use electromechanical contacts and are well-suited to home automation without the complexity of SSR heat management.
What does 'forced-guided contacts' mean on a safety relay, and do I need it?
Forced-guided contacts (also called positively-driven contacts) are a mechanical design feature that ensures normally-open and normally-closed contacts cannot both be closed simultaneously — even if a contact welds shut due to fault current. This is a mandatory requirement for safety relays used in emergency-stop circuits, light curtains, and machine guarding under EN ISO 13849. If your relay is in a safety function (Category 3 or 4, PLd or PLe), you need forced-guided contacts — full stop. For standard control applications with no safety function, it's an unnecessary expense. Phoenix Contact's PSR series and ABB's safety relay range both offer this feature.
How do I prevent relay contacts from burning out when switching inductive loads?
Fit a suppression device across the load — not across the relay contacts. For DC inductive loads (motors, solenoids), a free-wheeling diode wired in parallel with the load (cathode to positive) clamps back-EMF spikes effectively and cheaply. For AC inductive loads, an RC snubber or varistor (MOV) across the load is the standard approach. Some relays include built-in suppression; check the datasheet. Without suppression, each switching event causes arcing that erodes the silver alloy contacts — you'll notice increased contact resistance, then intermittent switching, then failure. This is entirely preventable.
What are the pitfalls of buying cheap no-brand relays for industrial panels?
The main risk is undeclared contact ratings — a relay labelled '10A' from an unverified source may fail at 6A under inductive load conditions, with no recourse. CE marking can be self-declared and is frequently abused on low-cost imports. For panel building in the UK, sticking to established brands (ABB, Schneider Electric, Siemens, Phoenix Contact) means the datasheet is trustworthy, replacement parts are available, and you have a paper trail for compliance purposes. The price difference between a genuine Finder relay and a no-brand equivalent is often marginal once you account for the cost of a panel fault. Save money by comparing prices across legitimate retailers — not by switching brands entirely.
How many switching cycles should I expect from a relay in 2026?
A quality electromechanical relay from ABB, Schneider Electric, or Siemens will typically be rated for 10 million mechanical cycles (no load) and 100,000 to 500,000 electrical cycles at rated load — the electrical endurance is always the limiting figure. At 10 switching operations per day, that's 27 years of service at rated load; at 100 operations per day, around 3 years. Solid-state relays offer 10–100 million electrical cycles, making them the right choice for high-frequency applications. Always check the electrical endurance figure in the datasheet at your actual load current — manufacturers often quote endurance at reduced load, which can be misleadingly optimistic.