Operation & Installation Manual V12-V6 2010-05-31.doc
31/05/2010
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5
Electrical Installation
5.1 Safety instructions
CAUTION!
INFORMATION!
The ALTOSONIC V12 ultrasonic gas flow meter is designed to meet requirements for
applications in potentially hazardous areas (explosion). The equipment is certified
accordingly (ATEX). Read the dedicated Explosion Safety Instructions Manual related to
this product before starting to work on this equipment.
As a general rule make sure power supplies are switched off and that the meter is free of any
voltage before working on electrical equipment. After switching off the power supply, the
main part that will retain electrical energy for some time is a bank of capacitors with a total
capacity of 4000
µ
F. Starting from 18 V the charge will disappear according to an exponential
decay curve. After 1 minutes the charge on these capacitors is decreased to 0,2 V,
representing an energy of 0,08 mJ. therefore the Ex d enclosure can safely be opened after
a waiting time of 1 minutes after switching off the power to the unit
It is still strongly recommended to use a gas detector in case of any risk that an explosive
gas mixture can be present.
Be aware of the general safety directives, local safety directives and detailed instructions for
working on electrical installations. Adhere to safety procedures, an authorized work permit is
usually required when working on equipment or premises having a hazardous area
classification.
5.2 Electronics enclosure and cable entries
The metal (SS 316) converter housing of the ALTOSONIC V12 contains the electronic circuit
boards of the ultrasonic flow meter. Three separate compartments contain
a.
connection block with screw terminals
b.
the electronic circuit boards including the display unit
c.
the power supply and serial communication line drivers.
See also sections 2.3.3 and 2.3.4.
The ALTOSONIC V12 electronics enclosure has six threaded holes M20x1,5 , three on
compartment a. and three on compartment c. The holes accommodate Ex d cable glands
suitable for cables wit a diameter from 6.5 to 14 mm to enter the enclosure. Unused holes
shall be closed with an Ex d approved stopping plug.
5.3 Electrical connections
5.3.1. Power connection
NOTE!
The ALTOSONIC V12 Ultrasonic Gas Flow Meter needs to be powered from a 24V dc
supply. Maximum power consumption is 10 W, a voltage variation of ±10% is acceptable .
