Filter
Top Products
Installation & User Manual
Ed 19UK June 2013
Page 20 of 28
Before installing intrinsically safe units within an approved installation, it is essential to ensure
that there are no deviations from the conditions of the order or the requirements of the approved
block schematic diagram and the following related instructions:
1. No circuits other than those shown on the drawing are permitted. There must be no
interconnection to any other circuits.
2. The intrinsically safe cabling must not be connected to non-intrinsically safe circuits, through
any plug, socket or other form of electric connector containing the cable.
3. Adequate precautions must be taken to prevent danger arising from the charging of the
intrinsically safe circuit by the contact leakage or inductance from any other circuit. To
prevent static electricity do not rub cables or amplifier housing with a dry piece of cloth.
4. The intrinsically safe circuit must be adequately insulated from earth in the hazardous area
and the insulation of all cabling must be at least 500 V r.m.s.
5. The safety barrier (zener barrier) must be placed in a safe area and be mounted within a
protective enclosure with a protection degree, at least equal to IP 20.
6. The cable between the safety barrier and the amplifier should be provided with a cable shield
which is connected to earth at the zener barrier. The impedance between the safety barrier
earth rail and a secure bond to the hull must not exceed 1 ohm.
7. Safe area apparatus must not be supplied from, nor contain, a source of potential with respect
to earth under normal or abnormal conditions exceeding 250V r.m.s. or 250 V DC.
8. The inductance/resistance ratio, total inductance and total capacitance, of the cable and the
amplifier must not exceed the values stated by the manufacturer of the approved safety
barriers.
9. Prevent impacts on the sensor housing to avoid sparks. Do not mount or dismount the sensor
when there is a hazardous condition in the tank. Be sure the tank is vented and gas free.
10. Be sure that the amplifier box is dry and clean before the lid is mounted. The four screws
in the lid should be tightened fully.
11. Be sure to order and use sensor cable with the right temperature specification. Check that
the ambient temperature for the entire cable run do not exceed the max limit for the cable.
12. MAS2600 contain no repairable parts. Repairing or fixing the circuit or replacing
components may impact the intrinsic safety.
13. The sensor cable shall remain in one piece from sensor to amplifier box.
Reference is made to manufacturer instructions of zener barriers and to the rules in force at the
time in question concerning intrinsically safe area installation.