Thermo Scientific Sarasota FD910, Руководство пользователя

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Installation
Electrical Considerations
2-2
Sarasota FD910, FD950, & FD960 User Guide Thermo Fisher Scientific

Pycnometer connections: Refer to the vertical installation drawing.

The density meter should be bolted to the adjoining pipework with a
suitable gasket between the coupling flanges. The configuration should
be in the most convenient direction for connection of electrical cables.
There are also electrical issues to consider prior to installation.

Terminal box: Six core screened cable should be run to the instrument
and inserted into the terminal box through a weatherproof cable gland
screwed into the 3/4" NPT threaded hole in the side of the box. The
bared ends of each wire should have the cable ends crimped or soldered
onto them and then be attached to the terminals in the terminal box.

Cable: As the output from the density transducer is in the form of a
modulated current loop of approximately 8 mA peak-to-peak, the
resistance and reactance of the cable is relatively unimportant provided
a signal no less than 1.3 V peak-to-peak is available at the density
converter or flow computer.

Zener barriers: For intrinsically safe installations, zener barriers or
galvanic isolators must be used. In these cases, cable capacitance,
resistance, and inductance must be within the statutory limits or be as
specified by the certifying authority. Zener barriers or galvanic isolators
must always be mounted in an area allowed by the barrier or isolator
certification.

Screening: Screening is always suggested, but in some cases, it may not
be necessary. When used, it must be earthed to the I.S. bus bar or
grounded only at the control room end of the cable.
The Sarasota FD910, FD950, and FD960 density meters have been
designed to satisfy the requirements of Clause 1.2.7 of the essential Health
and Safety Requirements such that they will not give rise to physical injury
when handled properly. The instruments do not produce excessive surface
temperature, nor do they emit infra red, electromagnetic, or ionizing
radiation.
Before starting installation work, ensure all power connections are isolated,
and take precautions to prevent power from being restored while work is
taking place. Hazardous area installations forbid the use of tools or
equipment that could produce an explosion hazard by causing a spark or
imposing excessive mechanical stress.
Electrical
Considerations
Hazardous Area
Installations