Gent S4 Heat Sensor
| Part no. | S4-720 |
|---|---|
| Brand | Gent |
| Range | S4 Detectors |
| Sub-range | Detectors Only |
Image for illustration; item supplied may differ
At a glance
- Heat sensorThermistor heat sensor. Sensing readings are sent to the control panel.
- 5 selectable sensing modesSTATE 0: Class A1 heat. The response is selected during commissioning.
- Addressable sensing channels2: heat.
- Integral short circuit isolatorThe head includes loop short circuit isolation. S-Quad devices take their power from the loop at 35 V to 48 V.
- S-Quad mounting optionsFits the separate S4-700 base; the S4-FLUSH kit supports semi-flush mounting for white S-Quad heads.
- Nano loop loadingNano load factor 0.5 per device. The Nano panel limit is 127 devices on its loop, subject to loop loading.
Description
The Gent S4-720 is an addressable heat sensor for Vigilon Plus, Compact Plus and Nano fire alarm panels. A thermistor measures temperature, while the panel applies the selected heat response and any rate of rise calculation. Five sensing modes provide Class A1, B, BS, A2S and A2 heat detection, with Class A1 as the default. The head takes its power from the loop and includes a short circuit isolator. It fits the separate S4-700 base and has a white ABS housing with a red fire LED. The S4-780-S combines heat detection with an integral sounder where the system needs audible warning at the sensor.
The S4-720 measures heat with a thermistor and reports it on analogue channel 2. The control panel sets the fire threshold and calculates any rate-of-rise contribution to the fire decision. This is a heat-only head, with no optical smoke channel or integral sounder. The S4-780-S combines heat sensing with an audible alarm in one head.
Read the full technical description
The S4-720 measures heat with a thermistor and reports it on analogue channel 2. The control panel sets the fire threshold and calculates any rate-of-rise contribution to the fire decision. This is a heat-only head, with no optical smoke channel or integral sounder. The S4-780-S combines heat sensing with an audible alarm in one head.
Five heat modes are selectable during commissioning: STATE 0 is Class A1, STATE 5 is Class B, STATE 6 is Class BS, STATE 7 is Class A2S and STATE 13 is Class A2. The factory setting is STATE 0. Class B suits higher ambient temperatures; Class BS has no rate-of-rise component. Class A2S provides fixed-temperature operation without responding to transient temperature variations.
S-Quad devices take power from the loop at 35 V to 48 V. This head includes a short circuit isolator. Its Nano load factor is 0.5; Nano allows a maximum of 127 devices on its loop. This maximum is subject to loop loading. Use the Battery Standby and Loop Load calculator to determine the installed device mix, cable length and standby requirement.
S-Quad heads plug into the separately ordered S4-700 base. Mount the base on a metal back box, maintain loop earth continuity and connect earth securely to the box. The base locking peg can secure the head against removal. A locked head needs access to the peg for release. The S4-FLUSH kit provides semi-flush ceiling mounting for the white S-Quad range.
The S-Quad programmable connection supports either a monitored input or an unmonitored output. The default output drives a remote repeat LED without a series resistor. One 13449-01 or SEN-LED remote indicator can connect to a base, with a maximum run of 15 m to the external I/O unit. The head is supplied with a dust cover, which must be removed before commissioning.
Specifications
| Device type | Addressable heat sensor |
|---|---|
| Sensor marking | H |
| Sensing elements | Thermistor heat sensor |
| Analogue sensing channels | 2: heat |
| Selectable sensing STATEs | 0, 5, 6, 7, 13 |
| Factory default | STATE 0: Class A1 heat |
| Compatible panels | Gent Vigilon Plus, Compact Plus and Nano |
| Power source | Loop powered |
| S-Quad loop operating voltage | 35 V to 48 V |
| Nano load factor per device | 0.5 |
| Nano panel loop limit | 127 devices maximum, subject to loop loading |
| Short circuit isolator | Integral |
| S-Quad isolator voltage data | Vmax 48 V; Vnom 40 V; Vmin 35 V; Vso max 16 V; Vso min 8 V |
|---|---|
| S-Quad isolator current and impedance | IC max 0.8 A; IS max 1.25 A; IL max 50 microamps; Zc max 0.13 ohm |
| S-Quad head dimensions | 117 mm diameter x 49.6 mm high |
| S-Quad height with standard base | 63.8 mm |
| S-Quad housing | ABS; white RAL 9010 |
| S-Quad operating temperature | -10°C to +50°C |
| S-Quad storage temperature | -20°C to +70°C |
| S-Quad relative humidity | 95% non-condensing at +5°C to +45°C |
| Mounting base | S4-700, ordered separately |
| S-Quad programmable connection | Monitored input or unmonitored output; default remote LED output |
| S-Quad external I/O cable limit | 15 m from base to external I/O unit |
Specifications per manufacturer documentation, subject to change. E&OE.
Standards and approvals
| Standard | What it covers |
|---|---|
| LPCB approved | Approved by the Loss Prevention Certification Board for fire detection and alarm system products. |
| EN 54-5:2002 + A1:2002 | |
| EN 54-17:2005 + AC:2007 | |
| EN 54-18:2005 + AC:2007 | |
| Declaration of Performance 001-CPR-2013 |
Approval body: Loss Prevention Certification Board (BRE Global Limited).
Documents
| Document | Type | Size | Download |
|---|---|---|---|
| Gent 4188-1073 issue 7 - S-Quad data and installation (white and black) | Installation | 7.2 MB | Download PDF |
Optional accessories
- S4-FLUSHS-Quad Semi-Flush Mounting KitOptional semi-flush fixing kit for the S-Quad device.£28.23ex VAT£33.88 inc VATIn stock
- 805580S-Quad Removal Tool KitRemoval tool kit listed as an associated product for the sensor.£327.18ex VAT£392.62 inc VATIn stock
FAQs
Which heat classes can be selected on the S4-720?
The S4-720 has five heat sensing STATEs. STATE 0 is Class A1 and is the factory default; STATE 5 is Class B, STATE 6 is Class BS, STATE 7 is Class A2S and STATE 13 is Class A2. The panel configuration determines the heat response and calculates any rate-of-rise contribution. Class BS has no rate-of-rise component, and Class A2S provides fixed-temperature operation unaffected by transient temperature variations. The selected STATE changes the response of the same thermistor-equipped sensor head.
Does the S4-720 detect smoke as well as heat?
The S4-720 detects heat through a thermistor and has no optical smoke sensing channel. It reports its heat reading on analogue channel 2, with the fire response controlled by the selected heat STATE at the panel. Its five options are Class A1, B, BS, A2S and A2. For optical smoke sensing alone, the S4-715 is the corresponding sensor; the S4-710 combines optical and heat detection. Each of these heads fits the S4-700 base and includes a short circuit isolator.
Which model adds a sounder to the S4-720 heat-sensing option?
The S4-780-S combines heat sensing with an integral tone sounder. It has the same five heat-class choices as the S4-720: A1, B, BS, A2S and A2, selected through commissioning STATEs. The S4-720 itself provides heat sensing without a sounder, voice output or visual alarm device. Both take power from the loop and include a short circuit isolator. Both fit the separate S4-700 base. The S4-720 reports its heat reading on analogue channel 2.
Can the S4-720 be locked into its base?
Yes. The S4-700 base has a locking peg that can secure the S4-720 against removal. Once the head is locked, releasing it requires access to that peg; the standard extractor tool cannot remove a locked head remotely. The base is a separate order code and mounts on a metal back box with loop earth continuity maintained. White S-Quad heads can also use the S4-FLUSH semi-flush kit. Remove the head’s supplied dust cover before the fire alarm system is commissioned.
What Nano load factor applies to the S4-720?
The S4-720 has a Nano load factor of 0.5 per device, with a maximum of 127 devices on the loop subject to loop loading. The head takes its power from the loop and includes a short circuit isolator. S-Quad devices operate at 35 V to 48 V. Use the Battery Standby and Loop Load calculator for the installed device mix, cable length and required battery standby. The S4-720 connects through its separately ordered S4-700 base.
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