Oldham BM25, User Manual

Page: 73 / 80

9
– Special Instructions
73
Alarm relay output and dry logic input connectors
Input characteristics for the alarm relay output:
■
U
i
= 30 V max.
■
I
i
= 150 mA max.
Output characteristics for the dry logic input:
■
U
o
= 5 V.
■
I
o
= 50 mA.
■
L
o
= 8 mH.
■
C
o
= 7 µF.
Only circuits disconnected from power should be connected to digital input, or:
■
U
i
= 0 V.
■
I
i
= 0 A.
The two previous circuits are separate intrinsic circuits. The cables
connected to the ends of these circuits must comply with the requirements
for intrinsically safe circuit wiring: cable type, insulation voltage, insulation,
linear capacity and inductance. Refer to national and international
standards, for example EN/IEC 60079-14.
A Descriptive Document System should be established by the person responsible for the
installation as explained above.
Trickle charging connection (external power source)
The external power source for battery pack maintenance must be intrinsically safe and
must be compatible with the following gas detector input characteristics:
■
U
i
= 30 VDC.
■
I
i
= 160 mA.
■
C
i
= 0 µF.
■
L
i
= 0 mH.
It is possible to connect two external power supplies on the connector in accordance with
the rules specified in the previous paragraph.
Connectors wiring diagram
The paragraph Connections on page 13 describes the gas monitor's various
connections. Unused connectors must be equipped with their protective cap.