Hydrogen Monitoring Of The Analyzer Cabinet" Option - ABB ACX Commissioning Instruction

Installation Preparation

"Hydrogen Monitoring of the Analyzer Cabinet" option

Function
Scope of delivery
Installation
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If an FID (VOC Analyzer) is installed, the analyzer system can be supplied with the
'Hydrogen monitoring of the analyzer cabinet' option as an additional safety measure.
If a leak occurs in the hydrogen path inside the analyzer cabinet and hydrogen
accumulates inside the cabinet, both the hydrogen supply and the power supply are
shut off before the explosion limit is reached – at 40 % LEL. This prevents formation of
an ignitable mixture.
Installed in the analyzer cabinet:
•
in the upper area, an ATEX-certified gas sensor with connection socket,
•
on the exterior on the right-hand side wall, a solenoid valve, connected with the
combustion gas input of the analyzer cabinet, which cuts off hydrogen supply in the
event of a failure of the power supply, or at 40 % LEL (H
Also supplied:
•
a gas warning center for evaluating the gas sensor signal,
•
a contactor for disconnecting the power supply to the analyzer cabinet,
•
a contactor for disconnecting the UPS if the system is prepared for a UPS.
The electric wiring of the gas sensor and the gas warning center to shut down the
power supply in the event of a fault is not installed in the analyzer system in the
factory-delivered condition.
The gas warning center must be installed outside the analyzer cabinet in a non-
hazardous area in a distribution cabinet or similar. It must be electrically connected to
the gas sensor (see the order-specific set of drawings in this regard).
The solenoid valve for disconnecting the hydrogen supply (H
the contactors and relays for disconnecting the power supply and UPS (if present)
must be connected to a fault-signalling contact in the gas warning center. The fault-
signalling contact must be set so that the voltage is shut off at 40% LEL and the
contact itself latches.
The measuring signals (analog outputs and inputs), the status signals (digital outputs
and inputs) as well as the bus systems of the analyzer system are so designed that
after the power supply (and possibly the UPS) are disconnected no component in the
analyzer cabinet (contactor, relay, motor etc.) that could generate an ignition spark
can be actuated from the outside.
The measurement and status signals supplied potential-free as well as bus
connections must not be activated separately in the event of a gas alarm. If however a
non potential-free external signal is fed in, the operator should make sure that if a gas
alarm is triggered, it is activated via a cut-off relay, for example.
ACX Analyzer System Commissioning Instruction
safety valve).
2
) as well as the coils of
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CI/ACX-EN Rev. D