MBA200
·
Operating Instructions 8011417 V 2.2
·
© MBA Instruments GmbH Germany
6
Bin-level Indicator MBA200
3.3.4
Temperatures of the distance tube
Unit versions for high container temperatures above 80 °C
are equipped with a distance tube between unit head and
connection thread/flange. The purpose of the distance tube
is to keep high temperatures away from the unit head (max.
60 °C).
If the container is equipped with a thermal insulation:
Keep the distance tube free of thermal insulation, in order
to allow cooling by the ambient air.
Do not cover
the
distance tube with the insulation of the container.
Otherwise distance tube will not provide the required
cooling effect. Overheat can cause malfunctions and
damage the unit head.
WARNUNG: Risk of injury
The distance tube is possibly hot enough to burn skin
immediately when being touched.
If the container is hot:
Protect the distance tube against
accidental touching.
WARNUNG: Explosion hazard by dust contamination
The surface temperature of the distance tube can be
significantly higher than the unit head temperature.
Check if the dust-explosion limit value can be exceeded
when the surface of the distance tube is covered with
dust.
If this hazard exists:
Make sure that the distance tube
cannot be contaminated with dust, or that the distance
tube is periodically cleaned as a preventive measure.
3.4
Electrical connection
3.4.1
Important safety notes
WARNUNG: Free electrical contacts inside the unit head
Before opening the unit head, shut off the mains power
supply and all connected signal voltage. The electrical
circuits inside the unit head are not protected against
physical contact.
WARNUNG: High voltage inside the unit head (type 230)
In the type 230 unit head, there are always contacts with an
output of 230 and 115 V, even if the unit is powered with a
lower voltage (
page 9, § 3.4.6
).
Observe this information when operating the unit with
open unit head for service purposes. Take care. Give a
warning to other persons.
3.4.2
Safe electrical installation
A MBA200 should be installed and set-up by skilled
persons who can assess the tasks given and consider
the dangers involved.
The MBA200 is not equipped with a power switch or fuse.
Install an external power switch which can switch on and
off the mains power supply to the MBA200.
Provide an external mains fuse for the MBA200 (power
consumption
page 11, § 7.2
).
Use power cable with following conductor cross sections:
– Massive wire: max. 2,5 mm²
– Stranded wire: max. 1,5 mm²
Use cables which are specified for an ambient
temperature of at least 60 °C (140 °F).
Protect all cables against heat. Avoid contact with hot
surfaces (for example, the container wall). Consider
thermal radiation and heat accumulation.
3.4.3
Protection against explosion
WARNUNG: Explosion hazard
If the unit is used in an explosion-hazardous location,
the following criteria must be observed:
Certification:
– Check if the individual unit is applicable to the use in
the actual explosion-hazardous location (see
nameplate and delivered documents).
– Observe the „special conditions“ which are specified
in certification documents.
Equipotential connection:
In addition to the protective
earth connection (PE), install an equipotential bonding,
using the terminal on the outside of the unit head.
Cables:
Use only cables which fit to the cable glands. For
standard product versions, the outer diameter of the
cables must be 6
… 12 mm.
Cable glands:
The built-in cable glands may only be
replaced by components which are certified for the use in
the actual explosion-hazardous location (ATEX-certified).
Fixed installation:
Fix all connected cables in place over
their entire length.
Sparks:
Prevent generation of sparks inside the
container. Sparks can be generated when the shaft or the
paddle collides with metal parts. If the MaihakMBA is
equipped with a flexible shaft, sparks could be produced
when the shaft cable swings and the paddle collides with
the container wall.
Installation standard:
Make the installation in accordance
to the European standard EN 61241-14.
