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9) End of Line Monitoring (DC Units)
9.1
Standard DC End Of Line Monitoring
On D2xS2 DC units, DC reverse line monitoring can be used if
required. All DC sounders have a blocking diode fitted in their supply
input lines. An end of line monitoring resistor can be connected across
the +ve and –ve terminals. If an end of line resistor is used it must have
the following values:
24V DC Max Sounder
Minimum resistance 3K9 Ohms
Minimum resistance 1K Ohms
48V DC Max Sounders
Minimum resistance 15K Ohms
Minimum resistance 3K9 Ohms
The resistor must be connected directly across the +ve and -ve
terminals as shown in the following drawing. Whilst keeping its leads
as short as possible, a spacing of at least 1/16" (1.58mm) must be
provided through air and over surfaces between uninsulated live parts.
See D252-06-001 for details.
Figure 9: End of Line Resistor placement.
Note that the maximum forward polarity monitoring voltage is 6V. A
monitoring voltage greater than 6V may activate the alarm horn
sounder and the 2nd, 3rd or 4th stages.
9.2
Custom DC Multi-Stage End Of Line Monitoring
An optional 12-way terminal module is available to enable up to four
alarm stages to be activated from three DC voltage output channels.
The three alarm stage activation inputs can be independently
monitored.
Refer to Schematic D252-06-001, Config. 6.
Specify Product option 'V' when ordering.
Spare part code for field installation: SP78-0001
Figure 10: End of Line Resistor placement –
Optional 12-Way Terminal Module.
European Safety Systems Ltd. Impress House, Mansell Road, Acton, London W3 7QH
Document No. D252-00-001-IS
Minimum Power 0.5W
Minimum Power 2.0W
Minimum Power 0.5W
Minimum Power 2.0W
Issue 1
21-12-2023
10) Maintenance, Overhaul and Repair
Maintenance, repair and overhaul of the equipment should only be
carried out by suitably qualified personnel in accordance with the
current relevant standards:
For ATEx/IECEx or UKEx:
EN60079-19/IEC60079-19
Explosive atmospheres – Equipment repair, overhaul and
reclamation
EN 60079-17/IEC60079-17
Explosive atmospheres – Electrical installations inspection
and maintenance
Units must not be opened while an explosive atmosphere is present.
If opening the unit during maintenance operations, a clean
environment must be maintained and any dust layer removed prior to
opening the unit.
To avoid a possible ELECTROSTACTIC CHARGE the unit must only
be cleaned with a damp cloth.
11) SIL 2 Reliability Data
Reliability and Functional safety IEC/EN61508 which has been
assessed and is considered suitable for use in low demand safety
function:
1.
Random Hardware Failures and Architectural constraints (route
2
).
H
2.
As an unvoted item (i.e. hardware fault tolerance of 0) at SIL 2.
The product was assessed against failure modes:
•
Failure respond to an input by sounding sounder.
•
Spurious sound output despite no input.
3.
When employing the device in a SIL2 compliant system the user
should ensure frequent or continuous automatic monitoring of
continuity.
Integrity in respect of failure to function
Total Failure rate
"Hazardous" failure rate (revealed)
"Hazardous" failure rate (unrevealed)
"Safe" failure rate (revealed)
"Safe" failure rate (unrevealed)
System type
Hardware Fault Tolerance
Diagnostic Coverage
PFD (hazardous failure)
Proof Test Interval
www.e2s.com
SIL2 & SIL1
0.55 pmh
0 pmh
0.55 pmh
0 pmh
0
B
0
>80%
-3
2.4 x 10
Up to 1 year
Tel: +44 (0)208 743 8880
Sheet 6 of 7
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