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Design, Assembly and Service Manual
Page 22 of 32
Electromagnetic flowmeter FLONET FN50xx.1
ELIS PLZEŇ a. s.
6. FLOWMETER INSTALLATION AND OPERATIONAL START
The meter installation work shall be performed in strict observance of the procedures and rules described in this manual.
To prevent undesirable interference, the power cables shall be laid at least 25cm away from all signal cables. All cables shall be laid outside the thermal insulation layer on the piping (if any). Only shielded conductors shall be used and shielding shall be connected to the earth potential on the side of the plant control system.
6.1. Sensor installation
The measurement point chosen for the sensor installation should ensure that the internal part of the sensor is fully flooded with the measured liquid at all times. If the sensor is mounted in vertical position, the only permitted liquid flow direction is upwards.
No thermal insulation shall be used on the sensor body. If the flowmeter is to be installed in a pipeline with thermal insulation, the insulation shall be removed at the sensor insulation point.
The internal diameters of the piping and the sensor tube shall be identical. The input and output piping sections including seals shall be perfectly aligned, with no protruding edges. The arrow on the sensor body indicates the required fluid flow direction (positive flow direction).
Do not expose the electronic unit box to direct sunlight; in the cases of outdoor installation, use a suitable protection shield.
6.2. Electric connections of electromagnetic flowmeter
The terminals for connecting cables can be accessed upon removal of the upper lid of the electronics box.
The lid is screwed by four bolts. A schematic diagram of the connecting is shown on the bottom side of the lid.
Examples of labels showing power supply and impulse output
6.2.1. Connection to power source
Terminal
BN
BU
N neutral conductor
L phase conductor
To connect the power source, use a standard cable of three conductors of square section not exceeding 2 x
1.5mm
2 . For ambient temperatures, over 50°C, use a cable with rated operating temperature of at least
90°C. The box grommets will only accommodate cables with outer diameter between 4 and 8mm. Use of any other cable would disturb the protection of the IP 65 box.
The earthing conductor shall be longer than both the phase and neutral conductors. This is a safety requirement as in the case of loosening the cable clamping in the gland, the earthing conductor shall be the last to be disconnected from the terminal.
The power supply line shall be protected by an overcurrent circuit breaker. A seal should be applied on the breaker to prevent unauthorized handling. The electronic unit has no independent power switch. The recommended rating of the overcurrent circuit breaker is 4 to 6A.
ELIS PLZEN a. s., Lucni 425/15, 301 00 Plzen, Czech Republic, Phone: +420/377 517 711, fax: +420/377 517 722 Es90716K
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