ORBIS
10
ORBIS
HEAT
DETECTOR
Part Number ORB-HT-11001-APO
WHERE TO USE HEAT
DETECTORS
Heat detectors are used in applications
where smoke detectors are unsuitable.
Smoke detectors are used wherever
possible since smoke detection provides
earlier warning of fire than heat detection.
There are, however, limits to the
application of smoke detectors and these
are described in the section ‘features of
Orbis’ on page 4.
Heat detectors should be used if there is
a danger of nuisance alarms from smoke
detectors.
ORBIS HEAT DETECTOR
The Orbis range incorporates seven heat
detector classes to suit a wide variety of
operating conditions in which smoke
detectors are unsuitable.
The European standard EN54-5:2001
classifies heat detectors according to the
highest ambient temperature in which
they can safely be used without risk of
false alarm. The classes are identified by
the letters A to G. (Class A is subdivided
into A1 and A2.) In addition to the basic
classification, detectors may be identified
by a suffix to show that they are rate-of-
rise (suffix R) or fixed temperature (suffix
S) types.
All heat detectors in the Orbis range are
tested as static or rate-of-rise detectors
and are classified as A1R, A1S, A2S, BR,
BS, CR and CS.
USE A1S or A2S
Choosing a heat detector
Fig. 3
Heat Detector Response Modes
Table 1
Class
(EN54–
5:2001)
Application
Temperature
Typical Max
Static Response
Temperature °C
Min Typ Max
A1R
25
50
54
57
65
A1S
25
50
54
57
65
A2S
25
50
54
61
70
BR
40
65
69
73
85
BS
40
65
69
73
85
CR
55
80
84
90
100
CS
55
80
84
90
100
© Apollo Fire Detectors Limited 2004-6/RHD
