Siemens SIMOCODE pro C System Manual page 317

Explanation of approval for explosion protection within the equipment (centrifugal pump):
In practice, very rarely zone 0 (gas/vapor/mist) will be present inside the pump, but possibly
zone 2, sometimes also zone 1. These use cases are covered by the approval for zone 0.
For requirements according to zone 2 and zone 1, SIMOCODE pro can be used as the sole
safety device to protect against dry running - depending on the overall protection concept of
the operator. For requirements according to zone 0, SIMOCODE pro can be used as a
building block in addition to other independent safety devices - here too, depending on the
overall protection concept of the operator.
The devices/modules are also marked with the following warning:
"WARNING – this enclosure contains equipment forming part of an ignition protection system
in accordance with ISO 80079-37."
NOTICE
Monitoring equipment required
Take steps to ensure that the system cannot operate without any additional monitoring
equipment required by the overall ignition protection concept.
NOTICE
Points to observe
To ensure that SIMOCODE pro is used as intended for dry-running protection for
centrifugal pumps by active power monitoring in hazardous areas, observe the stipulations
from this manual as well as the stipulations from the manuals provided by the
manufacturers of the centrifugal pump and the motor.
The devices are suitable for dry-running protection of centrifugal pumps by active power
monitoring in hazardous areas in accordance with the above standards.
Tests other than those legally stipulated (Ordinance on Industrial Safety and Health) are not
required.
SIMOCODE pro
System Manual, 05/2019, A5E40507475002A/RS-AD/004
14.2 Dry-running protection for centrifugal pumps by active power monitoring
Safety and commissioning information for Ex areas
317