KROHNE UFM 500 EN - Manual (Page 7)

7
❹ Grounding with measuring ground M for separate
system flowmeters UFM 400 F / UFM 500 F
Do not connect up protective conductor PE incorporated
in the power supply cable, see sect. 2.2.2!
MR 02/04 Sensor cables, factory supplied, see sect.
2.2.3 for connection.
V Connecting cable, cross-section
≥
4 mm
2
(AWG 10) Cu, equip with M6 cable lugs,
customer supplied.
M Measuring ground; ground conductor,
cross-section
≥
4 mm 2 (AWG 10) Cu,
equip with M6 cable lugs, customer
supplied. Threaded hole in housing M4, 6
mm (0.24”) deep.
1.3.3 Grounding in hazardous areas
Special regulations are applicable, refer to sect. 6.1, and
the special “Ex” installation instructions.
1.4 Pipes with cathodic protection
•
Pipes with electric corrosion protection are generally
insulated inside and outside so that the fluid has no
conductive connection to ground. The primary head
must be insulated from the pipe. Note the following
when installing the flowmeter:
•
The pipe flanges must be connected to each other
using a copper cable (L), but must not be connected
to the primary head.
•
The bolts for the flange connections must be
insulated. Use sleeves and washers that made of
insulating material. Must be provided by customer.
1 Flange of 3 Pipe flange 6 Washer
Primary head 4 Bolt 7 Insulating
2 Gasket 5 Nut sleeve
•
Grounding
I Insulated bolts
L Copper cables
For grounding, be sure to read the instructions given in
sect. 1.3.1 and 1.3.2!
2. Electrical connection
2.1 Compact flowmeters UFM 400 K, UFM 500 K
2.1.1 Installation location and cable diameter
Location
•
Do not expose the compact flowmeter to direct
sunlight. Install a sunshade if necessary.
•
Do not expose to intensive vibration. If necessary,
support the pipeline to the left and right of the
flowmeter.
Cable diameter
To conform to protection category requirements, observe
the following recommendations:
•
Cable diameter: 8 to 13 mm (0.31” to 0.51”).
•
Enlarge inside diameter by removing the appropriate
onion ring(s) from the seal of the screwed conduit
entry only if cables have extremely tight fit.
•
Fit blanking plug Pg 16 and apply sealant to unused
cable entries.
•
Do not kink cables directly at conduit entries.
•
Provide water drip point (U-bend in cable).
Conduit installation, general wiring consideration
•
When electrical codes require conduit, it must be
installed in such a manner that the meter terminal
compartment remains dry at all times.
•
Power and output wiring should be run in separate
conduit.
•
Use twisted pairs for output wiring.
Warning: Power wiring should utilize a grounded
neutral conductor to avoid possible shock hazard /
damage to component parts.
L
I
I
I
I
3 2 1
6
4
6 7
5
Not included with meter, must
be provided by customer.
MR 02
MR 04
V
M