www.trimodbesta.com 3 │8 LTB011EN │2016.04
1.
Safety Instructions
The operating manual must be read and understood before installation. If you are uncertain on any
point, please contact Bachofen AG, Switzerland.
The electrical connection may only be carried out by qualified personnel who have been authorised by
the operator.
All attached cables and cable bushings must comply with the requirements of IEC 60079-0 Appendix
A – explosion-proof cables and cable entries.
The supply voltage may only be applied after the cover has been closed. Please ensure that you
always observe the special regulations concerning work on explosion-proof devices and during work in
potentially explosive atmospheres at the operators site.
Every Trimod Besta level switch must be selected by qualified, trained personnel in accordance with
the specifications stipulated by the customer. These specifications must be kept by the operator in a
safe place, together with the operating instruction, the customer-specific designation and the type
number (see type plate). In the event of any deviation of the physical quantities (pressure,
temperature, density, etc.) from the original specification, the suitability of the level switch must be
checked again by qualified, trained personnel or by the manufacturer, with regard to the new
specifications.
If the device is mounted in a partition wall, which separates zones from one another, and if category 1
or 2 equipment is necessary, an equipotential bond must be made (contact resistance ≤MΩ) between
the metal housing of the level switch and the wall of the container.
The float and flange module must be included in the regular plant pressure tests.
Process vessels / float chambers must be brought to atmospheric pressure before work is carried
out and must be appropriately vented.
The devices may, under no circumstances, be used as a support aid or as a security fixture for
equipment structures or for persons.
When you are using a Trimod Besta level switch in a safety application according to
IEC 61508 and IEC 61511, the safety manual must be taken into consideration before
installing and commissioning the switch. The safety manual lists the restrictions and limitations of the
IEC 61508 certification of the Besta Trimod level switch. The safety manual can be downloaded from
http://www.trimodbesta.com/en/downloads/approvals/sil.html
2. Conformity of standards
Trimod Besta level switches type B…8 conform with the requirements of:
EN 60079-0, EN 60079-11, EN 60079-26
IEC 61508:2010 (Safety Integrity Level)
3. Technical Data
Ex-protection-data
Explosion protection Ex ia IIC T6 Ga/Gb
IECEx Certification of Conformity IECEx EPS 15.0038 X
Safety Integrity Level (SIL)
Type B…5 SIL 1 (SIL 3 capable)
Type BB…5 SIL 2 (SIL 3 capable)
Electrical connection
The electrical connection should be carried out in accordance with the regulations for explosion proof
devices.
Not suitable for the switching of motor loads and incandescent lamp loads. The device is not protected
against excess current.
