Introduction to the CDVI VHLD 12 Vdc Delay Module
Product:VHLD Delay Module 12 Vdc (3 6s) NO/NC Relay (ITM002672) —12 Vdc Delay Module (3 6s). Compact, purpose-built and economical, the CDVI VHLD provides a short, adjustable hold-off period for fail-safe locks and other access control outputs. It holds the lock output off for an adjustable 3 6 seconds when power is reapplied, then restores power automatically. Designed with installers and integrators in mind, the VHLD is a space-saving solution that eliminates the need for a separate relay or external timer in many simple push-button RTE scenarios.
Key features at a glance
- Adjustable delay:3 6 seconds for short hold-off timing suitable for most RTE (request-to-exit) operations.
- Supply:10 15 Vdc nominal 12 Vdc — compatible with typical access control power outputs.
- Output:Single relay 1 x NO/NC, usable with fail-safe locking devices (consult datasheet for exact contact ratings).
- Form factor:Very compact (approx. 65 7 24 7 16 mm) for PCB or enclosure mounting; ideal where panel space is limited.
- Ingress protection:IP22 — intended for indoor installations in protected enclosures.
Detailed specifications and benefits
- Delay range:Adjustable 3 6 seconds — quick and simple adjustment allows you to tailor behaviour to the site requirement.
- Supply voltage:10 15 Vdc (nominal 12 Vdc) — works with standard access control power supplies.
- Relay/contact:1 x NO/NC. Contact rating is approximately 3 5 A but installers should consult the CDVI datasheet for exact conditions and derating.
- Dimensions:Approx. 65 7 24 7 16 mm — small enough for tight cabinet layouts or PCB mounting.
- Weight:~0.01 kg — ultra-light for easy mounting.
- IP rating:IP22 — suitable for indoor, protected enclosures; avoid exposed outdoor installation without additional protection.
- Simplicity:The VHLD is a single, focused module: set the delay, fit it in the enclosure, wire the lock output. No complex programming or extra modules needed for basic hold-off operation.
- Space and cost savings:Its compact size and one-piece design reduce panel clutter and can remove the need for a separate timer relay. For small installations this is a real material and labour saver.
- Reliability:Designed for the access control environment with a straightforward electromechanical relay output; easy to troubleshoot and replace if needed.
- Flexibility:Adjustable timing lets the same module serve several different door behaviours — from very short hold-offs to slightly longer delays for wider doors or multi-user egress.
Use cases and scenarios where the VHLD excels
The VHLD is ideal for request-to-exit (RTE) push-button arrangements where you want the lock to remain de-energised for a short, defined period when power is reapplied. For example, after a power interruption or during maintenance, you may want the lock to remain off long enough for personnel to exit safely before the lock re-energises.
In apartments, small offices, retail fit-outs or local utility rooms where full access control panels are unnecessary, this module provides a neat, low-cost solution. Its compact footprint means it fits easily into small enclosures next to the power supply or lock wiring without requiring an additional DIN rail relay or timer module.
When upgrading existing doors to fail-safe locking or adding a simple hold-off feature to an existing access control system, the VHLD can be integrated quickly with minimal rewiring. Because it doesnBt require specialised software, electricians and installers can commission it on-site in minutes.
Fail-safe locks are designed to drop bolt or unlock on loss of power. The VHLD prevents immediate reapplication of power for a short period, which can be helpful during testing, intermittent power events, or controlled maintenance where a short hold-off avoids accidental locking during a service task.
How the VHLD compares with similar products
There are several approaches to creating a short delay or hold-off in access control systems: programmable access controllers, standalone time-delay relays, and small dedicated modules like the VHLD. Each has pros and cons.
- Programmable controllers offer maximum flexibility (schedules, multi-event logic), but they are more complex, costlier, and often oversized for a single short hold-off requirement.
- The VHLD is purpose-built and lower-cost. If you only need a single configurable delay for a fail-safe lock, the VHLD is the leaner option.
- Generic timer relays can provide a wide range of timings and modes but may be larger, require DIN-rail space, or be over-specified for the simple 3 6s hold-off use case.
- The VHLD wins on size and plug-and-play simplicity for access control-specific tasks.
- Solid-state modules with MOSFET outputs can be useful for low-power switching, but mechanical relay outputs like the VHLDs are often preferred for switching lock power due to their clear on/off state and ease of replacement.
- If your application requires high inrush capacity or a higher contact rating than the VHLD offers, a relay or protection device sized appropriately will be necessary.
Installation considerations and safety
The VHLD is IP22-rated and intended for indoor mounting within a protective enclosure. Always follow the CDVI VHLD datasheet and installation manual for wiring, mounting and safety information. The relay contact rating is given approximately (3 5 A); if your lock or solenoid approaches or exceeds the modules contact limit, fit a properly rated protection or buffer relay to carry the heavy current and protect the VHLD. If in doubt, consult CDVI documentation or your supplier for compatibility guidance.
Customer feedback and reviews
While no formal published testimonials are embedded here, installer and integrator feedback on compact delay modules such as the VHLD tends to focus on a few recurring positives:
- Ease of fit: Installers appreciate the small footprint and straightforward wiring, especially when retrofitting into cramped enclosures.
- Reliability: Field reports commonly describe reliable operation in everyday RTE use with minimal service calls when installed correctly.
- Value: For simple hold-off needs the module is frequently described as good value compared to larger timer relays or upgrading to a programmable panel.
For site-specific references or case studies, ask your supplier or CDVI representative; many distributors can provide anonymised customer experiences relevant to your project type.
Conclusion: Why the VHLD is a great choice for simple delay needs
The CDVI VHLD 12 Vdc Delay Module (3 6s) is an effective, low-cost, and compact solution for adding a short hold-off to fail-safe locks and other access control outputs. It excels where simplicity, space-saving and predictable behaviour are priorities: push-button RTE doors, small commercial fit-outs, and retrofit projects. Its adjustable 3 6s delay, single NO/NC relay output and compatibility with common 12 Vdc access control supplies make it a practical choice for installers who want a reliable timer without the complexity or expense of larger control systems.
Before specifying, always check the datasheet for exact contact ratings and installation guidance and consider adding a protection relay if your lock current approaches the modules limits. For straightforward short-delay requirements, the VHLD often represents the best balance of price, footprint and functionality.
- Model:VHLD (ITM002672)
- Function:3 6s adjustable delay for fail-safe locks
- Supply:10 15 Vdc (nom. 12 Vdc)
- Output:1 x NO/NC relay (approx. 3 5 A — consult datasheet)
- Suggested price:A329.99
