Introduction: Meet the Haydon 24V DC 3A Boxed PSU
Haydon HAY-DC24V3ABBLPSUis a purpose-built boxed AC/DC power supply designed for security, intruder and access-control installations. Combining a protected 24 VDC output with integrated battery backup, tamper detection and a mains-fail relay, this unit addresses the core needs of modern security systems: reliable power, supervision and simple system integration. Housed in a lockable metal enclosure sized to accept two 12 V lead-acid batteries (recommended 2 × 7 Ah), the Haydon PSU is a compact, practical and robust solution for installers and system designers.
Key features at a glance
- 24 V DC single output(nominal ~27.6 VDC on mains) capable of supplying up to 3.0 A.
- Integrated battery backup/chargersupporting 2 × 12 V lead-acid batteries with automatic switchover on mains failure.
- Universal mains input: 90–264 VAC, 50–60 Hz for straightforward global / variable-voltage installations.
- Local status indicatorsfor mains, battery and fault conditions, aiding rapid fault-finding and commissioning.
- Tamper signalling: lid and rear volt-free contacts to integrate with alarm panels for enclosure supervision.
- Mains-fail relay: changeover volt-free contacts (N/O & N/C) for system supervision or logging.
- Protection: electronic overload/short-circuit protection and transient suppression to suit commercial and security environments.
Detailed specifications and their practical benefits
Understanding the technical spec is important for selecting the right PSU for a given application. Below we break down the Haydon HAY-DC24V3ABBLPSU specifications and explain the benefits in real-world terms.
- Mains input:90–264 VAC, 50–60 Hz — the wide input range makes the unit suitable for installations with varied mains voltages or international environments, simplifying stock and deployment.
- Mains fuse:3.0 A, 250 V — user-protective fuse on the input side helps reduce risk of upstream faults propagating into the unit.
- Transient protection:Yes — helps protect connected equipment from voltage spikes common in commercial or industrial sites.
- Nominal voltage:27.6 VDC when on mains — this higher-than-24V nominal under mains ensures adequate headroom for devices that draw regulated 24 V while batteries are being charged or when loads vary.
- Max current:3.0 A — suitable for powering single or multiple security devices (control panels, readers, locks, small cameras or auxiliary devices) within the amperage envelope.
- Ripple:≤150 mV p-p — low ripple helps sensitive electronics such as access controllers and alarm panels operate reliably without false triggers.
- Load fuse & overload protection:3 A load fuse with electronic shutdown on overload/short — safeguards both the PSU and downstream devices; automatically resets once faults are cleared on mains.
- Configuration:2 × 12 V lead-acid in series — provides a supervised 24 V backup source when mains fails.
- Recommended capacity:2 × 7 Ah — balances runtime and enclosure size for typical security installations.
- Charger current:~0.5 A max — gentle charging prolongs battery life while maintaining readiness.
- Auto switchover:Automatic change to battery on mains fail — seamless transition reduces system downtime and avoids manual intervention.
- LEDs:Mains (green), Battery (orange/green/red), Fault (red) — immediate visual status aids commissioning and routine checks without tools.
- Tamper:Lid & rear volt-free contacts (normally open) — allow the enclosure to be monitored by the alarm system for unauthorised access.
- Mains-fail relay:Changeover volt-free contacts (COM, N.O., N.C.) — enables central logging or triggering of external devices when mains changes state.
- Operating temperature:-10 °C to +40 °C; storage -20 °C to +60 °C — suitable for indoor protected environments.
- Humidity:95% RH non‑condensing — typical of well-specified electrical enclosures.
- Box size and enclosure:360 × 330 × 90 mm lockable metal box — fits 2 × 7 Ah batteries and offers physical security and cable management for tidy installations.
Use cases and scenarios where the Haydon PSU excels
The HAY-DC24V3ABBLPSU is optimised for security and access control environments. Typical and high-value use cases include:
- Intruder alarm panels:Most alarm control panels require a 24 V supply and a supervised battery. This Haydon unit provides both in a single, installable enclosure with tamper contacts for panel supervision.
- Access control systems:Door controllers, electromagnetic locks and proximity readers often run from 24 V sources; the PSU supports these devices while ensuring doors remain powered during mains outages.
- Perimeter and remote sites:Small outbuildings, gate controllers and perimeter detection hubs benefit from the robust enclosure, battery backup and transient protection the unit provides.
- Small CCTV or auxiliary devices:While not sized for heavy camera arrays, this PSU can power individual cameras, junction boxes or lighting circuits that accept 24 V input.
- Supervised systems requiring logging:The mains-fail relay provides a volt-free contact to alert central monitoring or automation systems of power events, improving fault reporting and response times.
Comparisons with similar products on the market
When selecting a boxed PSU with backup, installers typically weigh factors such as output current, battery capacity, enclosure size, supervised signalling and protective features. Here’s how the Haydon compares in typical decision criteria:
- Power and current:At 3 A, the Haydon sits in the mid-range for security PSUs. Some competitors offer higher current (5–10 A) for larger panels or multiple peripherals; others offer lower-current compact models for single-device installations. Choose Haydon when you need a reliable mid-power supply with battery backup.
- Battery integration:The Haydon’s support for 2 × 12 V lead-acid batteries in a lockable enclosure is standard for security use; a few rivals use external battery boxes or only provide single-12 V solutions. On-board battery charging and auto switchover are real advantages for streamlined installs.
- Signalling & supervision:The combination of lid/rear tamper contacts and a mains-fail relay is a strength. Some low-cost options omit tamper contacts or mains-fail relays, reducing integration options when supervision is required by installers or insurers.
- Protection & robustness:With transient suppression and electronic overload protection, the Haydon aligns with professional expectations. Cheaper PSUs may lack robust transient suppression and can be more prone to nuisance failures in noisy electrical environments.
- Enclosure and fitment:The lockable metal box sized for 2 × 7 Ah batteries is convenient; smaller boxes that don’t accept batteries require separate battery enclosures—adding complexity and cost to installations.
Customer feedback and typical user impressions
While individual reviews for specific part numbers can vary, installers and system integrators typically comment on a few consistent points when evaluating PSUs like the Haydon:
- Reliability:Installers report that units with integrated charger and supervised outputs reduce call-backs when specified correctly and installed with correct batteries.
- Ease of installation:The presence of clear LED indicators, labelled terminals (V+, V-, B+, B-, COM/N.O./N.C.) and a lockable enclosure speeds up commissioning and handover.
- Value for money:For projects requiring supervised backup and tamper detection, a boxed unit such as this often represents better value than buying a separate PSU and battery box.
- Maintenance:Users appreciate the gentle charger current (~0.5 A) which helps prolong battery life; routine visual checks of LEDs and battery condition are straightforward.
If you require peer reviews or site-specific case studies, check supplier pages or trade forums where installers post field experience and tips for battery selection and wiring practises.
Conclusion: Why choose the Haydon HAY-DC24V3ABBLPSU?
The Haydon 24V DC 3A boxed PSU with battery backup, tamper and mains-fail relay is a sensible, professional-grade choice for security and access control installations that require a supervised 24 V source. It combines the most-requested features — integrated battery charging and automatic switchover, tamper contacts and a mains-fail relay — into a tidy, lockable enclosure designed for typical 2 × 7 Ah battery fitment. With universal mains input, built-in protection and straightforward status indication, the unit simplifies installation, reduces parts count and supports reliable operation during mains outages.
For projects that need a mid-power, supervised 24 V supply with good integration options, the Haydon unit represents a balanced option in terms of capability and cost. Suggested retail pricing positions it competitively for professional installers who value reliability and built-in supervision. As always, ensure installation by a qualified electrician or security systems engineer, select appropriate sealed lead-acid batteries, and consult the manufacturer datasheet and local regulatory documentation for certification and warranty details prior to purchase.
