Dual Relay Controller CHQ-DRC2SCI — Loop‑Powered with SCI
Product:Dual Relay Controller CHQ-DRC2SCI (SCI), Loop‑Powered, 2× SPDT, 30 VDC 1 AType:Addressable Fire ModuleSuggested price:A374.99 (indicative)
Introduction: what the CHQ-DRC2SCI does and its key features
The CHQ-DRC2SCI is a loop‑powered analogue addressable dual relay controller designed for use with compatible Hochiki ESP fire panels. It brings two independently controlled change‑over (SPDT) relay outputs together with a monitored auxiliary input and an integral short‑circuit isolator (SCI) into a compact module or DIN‑rail package. Because it is loop‑powered, the module requires no separate power supply, simplifying installation in many panel-driven systems.
Key features at a glance:
- Loop‑powered single‑loop addressable module (ESP protocol)
- Two independently controlled change‑over (SPDT) relays (30 V DC, 1 A resistive)
- Monitored auxiliary input with EOL 10 k11 B1 5%
- Integral short‑circuit isolator (SCI) to protect the remainder of the loop
- Available as a boxed module or DIN‑rail variant; optional IP65 backbox (CHQ‑BACKBOX)
Detailed specifications and benefits
The CHQ-DRC2SCI is engineered to deliver reliable, installer‑friendly control and monitoring for discrete circuits in life‑safety and building management applications. Below is a focused summary of the most relevant specifications and the practical benefits they provide.
- Operating voltage:17 641 V DC. This wide operating window ensures compatibility with standard ESP loop voltages and stability under typical loop loads.
- Power consumption:Low‑power 170 11A (0.75 s wake); quiescent 800 11A; polling current typical ~22 mA B1 20%. Loop‑powered operation eliminates the need for local power arrangements, reducing wiring complexity and installation cost.
- Relay rating:Two change‑over (SPDT) relays rated at 30 V DC, 1 A (resistive). Suitable for controlling low‑voltage release circuits, shutdown signals, auxiliary relays or small DC devices directly from the module.
- Monitored auxiliary input:EOL 10 k11 B1 5% (0.25 W). Input thresholds are defined (ON ≈ 470 11; short <50 11; open >100 k11), enabling reliable reporting of power‑fail conditions, tamper switches, or remote contact statuses back to the panel.
- Integral SCI:The built‑in short‑circuit isolator prevents a loop short from taking down the entire circuit, enhancing continuity of service and simplifying fault diagnosis.
- Form factor:Module dimensions 157 × 127 × 35 mm (module + lid); DIN‑rail variant available for equipment racks and control cabinets.
- Optional IP65 backbox (CHQ‑BACKBOX):Adds environmental protection where dust or moisture is a concern; assembled depth with backbox is 79 mm.
- Operating environment:610 C2 B0C to +50 C2 B0C; storage C2 B0C to +60 C2 B0C; max 95% RH (no condensation at 40 C2 B0C).
- Protocol:ESP (Hochiki ESP / ESPintelligent) — ensure compatibility with the host panel before installation.
- Approvals:LPCB listed; check the datasheet for CE / UKCA and any SIL classification relevant to your application.
- Safety:Relay contacts are rated for small DC loads only; installers must not exceed the 30 V DC, 1 A resistive rating. Wiring should be performed by qualified personnel and in accordance with local regulations and the supplied datasheet.
Use cases and scenarios where the CHQ-DRC2SCI excels
The CHQ-DRC2SCI is a versatile interface device suited to a variety of fire and building management tasks. Its combination of two independent relays, monitored input and SCI makes it particularly useful in applications that require resilient control and clear reporting to the panel.
- Door release and access control:Use one relay to operate a door‑release circuit on fire alarm activation while retaining the second relay for a hold‑open device, interlock or manual override. The monitored input can report the state of the door or release circuit back to the panel.
- Shutdown of plant and HVAC systems:The module can control shutdown signals for fans, HVAC dampers or equipment isolation circuits, with the advantage of reporting auxiliary input states (e.g., a local manual stop or fan status) to the panel.
- Control of external relays and ancillary equipment:Where higher currents or AC loads are required, the module can drive an external relay coil or contactor; the second relay can be used for separate zones or redundancies.
- Retrofit and distributed installations:The loop‑powered design and DIN‑rail option make the CHQ-DRC2SCI convenient for retrofitting into plant rooms, control cabinets and modular distribution boards without adding local power supplies.
- Resilient loop protection:In installations where loop integrity is critical, the integral SCI provides local isolation of faults, keeping the remainder of the loop operational and aiding troubleshooting.
Comparisons with similar products on the market
When evaluating relay interface modules, installers commonly weigh factors such as relay capacity, power requirements, loop protection and environmental ratings. The CHQ-DRC2SCI positions itself by offering a balanced feature set for many building and fire applications:
- Loop‑powered vs externally powered modules:Loop‑powered devices like the CHQ-DRC2SCI remove the need for local power, simplifying installations. Externally powered modules may offer higher current outputs or greater switching capability, but require additional wiring, local PSUs and often add ongoing maintenance points.
- Single‑relay vs dual‑relay modules:Compared with single‑relay modules, the CHQ-DRC2SCI provides two independent SPDT contacts in one footprint, saving panel addresses and board space where multiple outputs are needed.
- Presence of SCI:Modules without a built‑in short‑circuit isolator can allow a single fault to disable multiple devices. The CHQ‑DRC2SCI's integral SCI is a practical advantage in larger systems where keeping the loop operational during a fault is important.
- Environmental protection:The optional IP65 backbox brings the module closer to industrial robustness; some competing modules require separate enclosures for outdoor or harsh environment use.
Customer testimonials and field feedback
Publicly available formal reviews for specific addressable modules are often limited because these products are purchased and specified by contractors, consultants and institutions rather than general consumers. However, field feedback from installers and system integrators who work with Hochiki ESP modules typically highlights the following themes:
- Ease of installation and the value of loop‑powered operation, which reduces cabling and eliminates the need for a local PSU.
- The practical benefit of two independent relays in one module for space and address savings in panels and control cabinets.
- Reliability of the integral short‑circuit isolator in preserving loop operation during faults, which reduces downtime and simplifies troubleshooting.
For precise warranty, service experience and user reviews, prospective buyers should consult their local distributor, integrator references or project case studies from the manufacturer.
Conclusion: why the CHQ-DRC2SCI is a strong choice
The Dual Relay Controller CHQ-DRC2SCI is a compact, well‑specified addressable module that meets a broad range of control and monitoring needs in fire and building management systems. Its loop‑powered design simplifies installation; the two SPDT relays deliver flexible control of local circuits; the monitored auxiliary input adds useful diagnostics and reporting; and the integral short‑circuit isolator significantly improves loop resilience.
When you need a dependable, installer‑friendly interface module for Hochiki ESP‑based systems—especially in situations where reducing wiring complexity and preserving loop integrity are priorities—the CHQ-DRC2SCI is a practical, cost‑effective option. Always confirm panel compatibility, observe the relay contact ratings (30 V DC, 1 A resistive) and follow the manufacturer datasheet and applicable regulations during installation.
Need more details?Contact your Hochiki distributor or system integrator for installation guidance, datasheets, wiring diagrams and to confirm regulatory approvals for your jurisdiction.
