Hochiki CHQ-MRC2/FS ESP Addressable Fail Safe Relay Controller | Integral SCI, Mains Rated
You may also need
Key features
- Fail-safe relay control built in
- Integral short-circuit isolator protects loop
- Auxiliary monitored input for faults
Downloads
Summary
The Hochiki CHQ-MRC2/FS(SCI)(SCI) is a loop-powered single input/output module built to switch mains-rated plant such as dampers, door magnets, extractors or shutdown circuits directly from your analogue addressable loop, with fail-safe relay control built into the unit itself rather than relying solely on panel logic.
View full overview Show less
That matters on site because it lets you specify one device for both the switching and the safe-state behaviour that access control and smoke damper jobs demand, cutting down on extra interface gear and wiring runs. You still need to confirm your control panel supports fail-safe operability, but once that’s checked you get a self-contained module ready to go straight onto the loop.
An integral short-circuit isolator (SCI) protects the rest of the loop if a fault occurs at this point, so a damaged cable or connector here does not take down devices further round the ring. The monitored auxiliary input gives you a second job for the module, whether that’s local power supply fault monitoring or a general-purpose supervised input.
Features
- Fail-safe relay control – relay drives to a defined safe state, useful for damper and door holder applications once you’ve confirmed panel compatibility
- Integral short-circuit isolator – protects the remainder of the loop if a fault occurs at this device
- Mains-rated relay output – 250 VAC at 5 A or 48 VDC at 2 A (resistive) for direct control of dampers, access control equipment, extractors or plant shutdown
- Auxiliary monitored input – supervised with an end-of-line (EOL) resistor for local power supply fault monitoring or general-purpose use
- Simple DIL switch addressing – straightforward loop address setting without software tools
- Deeper, glanded IP65 backbox option – available for harsher environments, and the CHQ-BACKBOX supports BS 7671 compliance; the module is also suitable for BS 7273-4 applications
FAQs
What is the CHQ-MRC2/FS(SCI) used for?
The CHQ-MRC2/FS(SCI) is a single input/output module that provides a mains-rated relay output for controlling ancillary systems within a fire detection installation. Typical applications include releasing or holding door magnets, shutting down plant and equipment, controlling dampers, and switching extractor fans. It is designed for use within Hochiki’s ESP analogue addressable fire detection systems.
What does “fail safe” mean in the context of this module?
Fail safe relay operation means the relay defaults to a predetermined safe state if the loop or power supply fails, rather than remaining in its last active state. This is important in life safety applications where a predictable response to a fault condition is required. Fail safe operability is subject to compatibility with the connected fire alarm control panel — check panel documentation before specifying.
What is the relay contact rating?
The relay contact is rated at 250 VAC @ 5 A (resistive load) and 48 VDC @ 2 A (resistive load). For mains AC switching, the connected control panel must be compliant with the Low Voltage Directive for SELV circuits. No fuses are fitted to the device, so the relay output circuit must be protected by a suitable over-current protection device.
What is the auxiliary monitored input used for?
The auxiliary monitored input can be used to monitor a local power supply for faults, or it can be configured as a general-purpose input to bring an external signal into the fire detection system. This adds flexibility where additional monitoring is required alongside the relay output function.
Is a DIN rail version available?
Yes. The CHQ-MRC2/FSDIN(SCI) is a DIN rail-mountable version of the same module, offering identical functionality in a compact green ABS format suitable for installation within a panel or cabinet. Both the standard and DIN versions feature an integral short-circuit isolator.
Can the module be used in damp or outdoor-adjacent environments?
A deeper, glanded IP65-rated backbox is available for installations where additional environmental protection is required. The module itself has a maximum humidity rating of 95% RH non-condensing at 40°C, and an operating temperature range of -10°C to +50°C.
Specifications
| Ordering Code | CHQ-MRC2/FS(SCI)(SCI) |
|---|---|
| Operating Voltage | 17 – 41 VDC |
| Low Power Mode (0.75s) | 100 µA |
| Quiescent Current (Typ) | 300 µA |
| Current Consumption | 22 mA ±20% (polling) |
| Current In Short Circuit | 8 mA |
| Maximum Short Circuit Current | 1 A |
| Relay Contact Rating | 48 VDC max, 2 A (resistive load); 250 VAC max, 5 A (resistive load) – control panel must comply with the Low Voltage Directive for SELV circuits |
| Input EOL Resistor | 10 kΩ, ±5%, 0.25 W |
| Input Threshold Level | ON = 470 Ω, short circuit <50 Ω, open circuit >100 kΩ |
| Storage Temperature Range | -30°C to 60°C |
| Operating Temperature Range | -10°C to 50°C |
| Maximum Humidity | 95% RH non-condensing (at 40°C) |
| Weight | 360 g (add 235 g when using CHQ-BACKBOX) |
| Dimensions | L157 x H127 x H35 mm (module plus lid); H79 mm overall with CHQ-BACKBOX fitted |
| Colour / Material | White ABS module, semi-opaque black ABS lid as standard |
| Fusing | No internal fuses fitted – external over-current protection required on the relay output |
| Approvals / Compliance | Suitable for BS 7273-4 applications; CHQ-BACKBOX supports BS 7671 compliance |
FAQ
Hochiki states that the state of the relay contacts is indeterminate until the unit is powered, so you should never assume a known default position during installation or testing. Always power the module up and verify the relay state before connecting it to safety-critical equipment such as a damper or door holder. Yes. Fail-safe relay control on this module depends on your control panel being compatible with fail-safe operability, so check this with your panel manufacturer or Huvo before specifying it for a BS 7273-4 application. No, there are no fuses fitted on this device. You need to add a suitable over-current protection device on the relay output circuit to prevent excessive current through the contacts. Yes, the input isn’t limited to power supply fault monitoring and can be used as a general-purpose supervised input, using a 10 kΩ end-of-line (EOL) resistor with defined thresholds for open and short circuit conditions. A deeper, glanded IP65 backbox is available for this module where a higher ingress rating is needed, and it can be used with the CHQ-BACKBOX to support BS 7671 compliance. Check the dimensions table, as fitting the backbox adds to the overall depth and weight of the installed unit.What happens to the relay if the module loses power or signal?
Does my fire alarm panel need to support anything special for fail-safe operation?
Is the relay output fused?
Can I use the auxiliary input for a general-purpose monitored contact?
Do I need a backbox, and does it affect the IP rating?
Downloads
- Datasheet (Adobe PDF)
Additional information
| Weight | 1 kg |
|---|---|
| Device Type | |
| Version | DIN Rail, Standard |
More Interface products from Hochiki
Ekho Wireless Single Input Module
£95.51 (inc VAT: £114.61)
Ekho Wireless Single Output Module
£201.91 (inc VAT: £242.29)
Hochiki CHQ-DIM2 | Intelligent Addressable Dual Input Module | 2 Independent Inputs, Integral Short-Circuit Isolator
Hochiki CHQ-MRC2 | ESP Addressable Mains Relay Controller | Integral Short-Circuit Isolator
Hochiki CHQ-PCM(SCI) | Analogue Plant Control Module | 4 Relay Outputs, 4 Monitored Inputs, SCI
Hochiki CHQ-POM | ESP Intelligent Powered Output Module | User-Selectable 2-32mA Output, Two Monitored Inputs
£26.65 (inc VAT: £31.98)
Hochiki CHQ-SIM | ESP Addressable Single Input Module | Compact Design, Flying Leads, Hand Held Programmable
£26.10 (inc VAT: £31.32)