Installation instruction for radial blowers for areas subject to gas and dust explosion hazards
07/2019 KARL KLEIN Ventilatorenbau GmbH
Page 19
GB
8
Additional steps to be taken when deploying blowers in
zone 21
Instruction!
Pursuant to DIN EC 14986, a permanent vibration monitoring system that is mounted
directly to the blower has been mandatory since May 2007 on blowers operating in zone
21.
Blowers can be procured from Karl Klein with the corresponding devices installed. In this
case, the customer will be provided with an installed vibration sensor and an optional,
separate monitoring device.
The monitoring device must be installed outside of the explosive area. Please refer to the
corresponding Installation instruction.
When implementing a customer designed solution, the following issues need to be taken
into consideration:
Only vibration sensors that are certified for zone 21 may be used.
The vibration sensor should preferably be installed on the A-side bearing enclosure
of the drive motor, in a horizontal orientation to the installation orientation.
The nominal sensor signal must be transmitted to a control or monitoring device that
is located outside of the explosive area. The control must shut the blower down if the
blower reaches critical vibration levels.
8.1
Vibration threshold values
Threshold values in
accordance with ISO
14694
Rigid mount
mm/s
Flexible mount
mm/s
Starting value
4.5
6.3
Alarm threshold
7.1
11.8
Cut-off value
9.0
12.5
The values apply to blowers in industrial settings.
9
Disposal
Reusing defective blowers and/or their components, such as the blower impeller wheels,
roller bearings, etc. can result in property damage and personal injury, as well as damage to
the environment.
All blower components must be properly disposed of in compliance with the national and
international laws and regulations.
