Apollo XP95 - Manual (Page 11)

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11
Fig.12 XP95 Heat Detector
ELECTRICAL
DESCRIPTION
The detectors are designed
to be connected to a two
wire loop circuit carrying
both data and a 17V to 28V
dc supply. The detectors are
connected to the incoming
and outgoing supply via
terminals L1 and L2 in the
mounting base. A remote
LED indicator requiring not
more than 4mA at 5V may
be connected between +R
and -R terminals. An earth
connection terminal is also
provided.
When a device is energised
the ASIC regulates the flow
of power and controls the
data processing. The
thermistor provides an output
over normal operating ranges
that is proportional to the
external air temperature.
This voltage output is
processed in the A/D
converter and stored by the
communications ASIC. It is
transmitted to control
equipment when the device
is interrogated. When a
count of 55 is exceeded the
alarm flag is initiated and
XP95 HEAT DETECTOR
XP95 Heat Detector
▲
Part Number 55000-400
OPERATING
PRINCIPLES
The XP95 heat detectors
have a common profile with
ionisation and optical smoke
detectors but have a low air
flow resistance case made of
self-extinguishing white
polycarbonate. The devices
monitor heat by using a
single thermistor network
which provides a voltage
output proportional to the
external air temperature.
The standard heat detectors,
55000-400 and 55000-420,
respond to increasing air
temperature in such a way
that they are classified as an
A2S device. See figure 13.
Both devices will give 55
counts at 55°C.
A high temperature CS heat
detector, 55000-401, which
can be installed in a typical
ambient temperature of
55°C is available. See
figure 14. This device will
give 55 counts at 90°C.
the device address is added
to the data stream every 32
polling cycles from its last
polling for the duration of
the alarm level condition,
except when an alarming
device is being interrogated.
This can provide a location
identified alarm from any
device on the loop in
approximately two seconds.
The detector is calibrated to
give an analogue value of
25±5 counts at 25°C.
ENVIRONMENTAL
CHARACTERISTICS
XP95 Standard Heat
Detectors operate over the
range -20°C to +70°C, the
High Temperature Heat
Detectors operate over the
range –20°C to +120°C.
The detectors are unaffected
by atmospheric pressure.
Fig.11 Schematic diagram - XP95 Heat detector