Hochiki HF-24 User Manual

HOCHIKI HF-24

FLAME DETECTOR

USER MANUAL

2 Hochiki HF-24 UV Flame Detector – Installation Manual

Table of Contents

Table of Contents 2

UV Detection Basics 3

Summary 3 Comparison of Spectral Characteristics 3 Structure of the UV tube 4 Basic Operating Circuit of the UV Tube 5

Mounting 5

Locations Suitable for Mounting 5 Locations Not Suitable for Mounting 6 Detectable Area 7 Mounting Example 8 Detector to Detector Distance 9

Performance Check 9

Maintenance & Inspection 10

Cleaning 10 Performance Check 10

Detector Specifications 11

Detectable Area 11 Specification 11 Compatible Bases 12

Hochiki HF-24 UV Flame Detector – Installation Manual 3

UV Detection Basics

Summary

The ultraviolet type flame detector, which uses a UV tube, absorbs feeble ultraviolet light contained in flames and detects them in the form of a discharge pulse train with the help of the photoelectric effect and electron avalanche phenomenon. The detector has a counter circuit, which prevents malfunctions from taking place because of single shot or momentary UV rays, such as lightening and cosmic radiation.

Comparison of Spectral Characteristics

 Curve #1: Response of UV tube  Curve #2: Sunlight  Curve #3: Sensitivity of the human eye  Curve #4: Tungsten filament lamp

4 Hochiki HF-24 UV Flame Detector – Installation Manual

Structure of the UV tube

Hochiki HF-24 UV Flame Detector – Installation Manual 5

Basic Operating Circuit of the UV Tube

Mounting

Locations Suitable for Mounting

 Location where fire is strictly prohibited  Location where there is a printing press  Garage  Film library  School  Department store  Art museum  VTR room  Factory  Hospital  Warehouse  Storage for critical materials  Computer data room  Hotel

6 Hochiki HF-24 UV Flame Detector – Installation Manual

 Important cultural property

Locations Not Suitable for Mounting

 Outdoors  Location close to germicidal lamp based on UV rays  Location where there is a machine which will produce electric sparks  Location where welding jobs are carried out  Location involving frequent vibrations and shocks  Location which will generate corrosive gas  Location calling for any explosion proof means  Location where there is a source of radiation  Location which tends to gather dust or oil film

Hochiki HF-24 UV Flame Detector – Installation Manual 7

Detectable Area

The detectable area depends on the distance from the detector to a flame as illustrated below. An alarm condition is produced when a required number of UV rays enter the UV tube, setting off the counter circuit.

8 Hochiki HF-24 UV Flame Detector – Installation Manual

Mounting Example

 The detector should be mounted above something on which you want

to lay stress

Hochiki HF-24 UV Flame Detector – Installation Manual 9

Detector to Detector Distance

In mounting more than one detector, the value of ‘R’ shown below is determined according to the detectable area mentioned in 2.2.

Performance Check

 Approximately one second after the power supply is switched on, the

detector which has been mounted reaches its’ normal operating condition

 Make flames within the detectable area using a candle or a lighter and

confirm that an alarm is produced within 5 to 30 seconds in the area approximately 3m apart from the sensor

 The flame of a candle or a lighter should satisfy the requirements shown

below

 Performance tests should be carried out in the area specified below

10 Hochiki HF-24 UV Flame Detector – Installation Manual

 Ultraviolet lamps or similar means are used for making performance tests at

a location where fire is strictly prohibited (this detector cannot be mounted at a location calling for any explosion proof means). If an ultraviolet lamp is used for testing purposes, then the lamp should have a maximum ultraviolet output @ 200nm.

Maintenance & Inspection

Cleaning

Any built up dust or oil film on the surface of the UV tube will significantly reduce its’ sensitivity. The exposure of the UV tube should be cleaned at its’ surface at regular intervals (half-yearly under normal environments). (In cleaning, take care that no undue force is applied to the UV tube.)

Performance Check

In addition to the soils above, there may be something, like larvae and webs, which hinders proper detection. In such cases, the sensor performance should be checked, as appropriate, using a lighter or the like.

Hochiki HF-24 UV Flame Detector – Installation Manual 11

Detector Specifications

Detectable Area

Specification

Ordering code; HF-24 Operating voltage: 15-30 Vdc (Nominal rating 24Vdc) Standby current: Detection angle: UV sensitivity range: 185 to 260 nm Maximum current in alarm state: 250mA(without base) Operating temperature range: Maximum humidity: Colour and case material: Ivory ACS Weight: 150g (210g with base)

200μA at 24Vdc 120° Cone

-10°C to +50°C 95%RH - Non condensing (at 40°C)

12 Hochiki HF-24 UV Flame Detector – Installation Manual

Compatible Bases

Type Order Code Function* Standard YBF-RL/4H5 2-wire common mounting base. Hochiki ‘SAFELINE’ YBK-RL/4H1 As standard but provides line

continuity using a Schottky diode.

Hochiki ‘LIVELINE’ YBK-RL/4H2H As standard but provides line

continuity using a Zener diode circuit ensuring all call points and remaining detectors are operational when any

number of detectors are removed. Addressable master base (ESP)

*Alarm control panel compatibility is required for certain base types.

YCA-RL/5H2 This base incorporates a simple DIL

switch allowing any address between

1 and 127 to be set. Although this

base allows a conventional zone of up

to 6 CD range detectors and bases,

only one HF-24 and no other

detectors may be used.

Hochiki Europe (UK) Ltd

Grosvenor Road, Gillingham Business Park,

Gillingham, Kent, ME8 0SA, England

Telephone: +44(0)1634 260133 Facsimile: +44(0)1634 260132

Email: sales@hochikieurope.com

Web: www.hoc hikieurope.com

Hochiki Europe (UK) Ltd. reserves the right to alter the specification of its products from time to time without notice. Although every effort has been made to ensure the accuracy of the information contained within this document it is not warranted or represented by Hochiki Europe (UK) Ltd. to be a complete and up-to-date description. Please check our web site for the latest version of this document.