14
PRS-UM-DP8-EN-Rev.4.1-16.08.2021
Detectors Connections
Panel can be connected and monitor 8 detectors with 4-20 mA output signal. V+, V-(GND)
and S ports must be connected via using three-wire cable. Detector connections supply 24
VDC power to detector and read the output signal of detector from S port. Thus connections
should be made correctly to do not cause any damage on the detectors. Detectors should be
connected with three-wire 0.5mm
2
cross section cable. Cable diameter will be increased
while distance increase between the panel and detectors. Recommended cable types per
distance are given in table 6:
Cable size
Cable type
Cable resistance
Maximum Cable length (L)
(cross sectional area)
nearest equivalent
Ω/km
Meters
0.5 mm2
20 AWG
36.8 Ω/km
400
1.0 mm2
17 AWG
19.5 Ω/km
750
1.5 mm2
16 AWG
12.7 Ω/km
1000
2.0 mm2
14 AWG
10.1 Ω/km
1250
2.5 mm2
13 AWG
8.0 Ω/km
1500
Table
7:
Typical cable details and maximum distance for cabling
Detector connections should be made with 3 core cable and pin definitions are as follows:
S
4-20 mA signal
-
GND (V-)
+
Supply (V+)
Table
8: Connection pin definitions
The panel is programmed as all channels in operation and connected to detectors. In case
less than 8 detectors used the system will raise fault status for unused channels and overall
panel status remain in fault status. In this case user should close (deactivate) unused
channels via using configuration menu steps.
Relay Outputs
S-DP8 panel has four relay outputs which are ALARM1, ALARM2, FAULT and AUX. Relay
connection ports are located right under the relays. Alarm relays are operating in latched
mode. Hence the panel will wait user intervention to clear alarm status even conditions
returned to normal. User should reset status via pressing Exit button to acknowledge any
alarm. The active relays can also be monitored via related LEDs on the panel. Relay details
and activation rules are given below:
ALARM1:
This relay will be activated when any of the detectors in the system will exceed the
programmed Alarm-1 level threshold. If there is oxygen detector used in the system,
ALARM1 is also used as the low oxygen level alarm.
ALARM2:
This relay will be activated when any of the detectors in the system will exceed the
programmed Alarm-2 threshold level. If there is oxygen detector used in the system,
ALARM2 is also used as the high oxygen level alarm.
FAULT:
This relay is normally energised, and it will be de-energised when any of the internal
fault detection measures detects a fault. The Fault LED will be activated also when line
