Siemens 7MB2531 Operating Instructions Manual page 66

Technical specifications
7.6 Technical specifications for operation in hazardous areas
Data values
Min. pressure of protective gas
with non-combustible sample gases
with combustible sample gases
Consumption in operation
with Ex px with leakage compensation
with Ex px with continuous purging
with Ex pz with simplified pressurized enclo‐
sure
Max. load on Ex p enclosure
Type test pressure on Ex p enclosure
Ex px safety equipment
In principle, any Ex px safety equipment with a type examination certificate to ATEX can be used.
This safety equipment must have at least the following features:
• A safety level of at least Category 3 to EN ISO 13849-1 for monitoring during pre-purging, and
a safety level of at least Category 1 to EN ISO 13849-1 for monitoring during operation, or a
transferable safety level from another comparable international standard.
• Settable pre-purging phase; protective gas flow must be ≥ 50 l/min
• Limiting of protective gas pressure during the pre-purging phase: < 165 hPa
• With leakage compensation or continuous purging = 1 l/min (depending on version)
• Connection of protective gas lines: ∅ 10 mm or ∅ 3/8" from/to the analyzer
• Inlet pressure for protective gas supply: 0.2 ... 0.4 MPa
• Relay contacts for all-pole isolation of the analyzer's power supply
• Relay contacts for disconnecting additional equipment (e.g. Ex isolating relay)
• Connection facility for key switch with intrinsically-safe scan
• Only for analyzer version with leakage compensation: Connection facility for key switch with
intrinsically-safe scan
Differential pressure monitoring
Only applies to analyzer version Ex p with leakage compensation.
The sample gas pressure must be present in the analyzer (within the specified limits, see
Technical specifications for operation in hazardous areas (Page 62)) in a fail-safe manner. If only
an operationally reliable supply is available, an additional differential pressure switch must be
provided (see also point 5 in "Special conditions" of the EC type examination certificate).
If flame arrestors are fitted, differential pressure switches and/or relative pressure sensors must
be connected via a T-fitting between the sample gas inlet couplings and the flame arrestors (see
AUTOHOTSPOT and assembly diagram for the version Ex p with leakage compensation
Connection diagram for the versions Ex px with leakage compensation (Page 37)).
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At least 50 Pa rel. (recommended 5 hPa rel.)
At least 50 Pa rel. (recommended 5 hPa rel.) or at least
50 hPa (recommended 5 hPa rel.) higher than the sample
gas pressure if the latter is greater than atmospheric pres‐
sure.
Max. 3 l/min. (typically: < 1 l/min.)
1 l/min
1 l/min
165 hPa (rel.)
250 hPa (rel.)
Compact Operating Instructions in accordance with EN 61010-1 and EN 60079-0
Compact Operating Instructions, 09/2018, A5E45779389002-01