Tyco F3200 Benutzerhandbuch

F3200 Installation & Programming Manual

Document No: LT0122

Applications

Page 9-22

5 July 2001

Issue 2.7

AS 2380

Electrical Equipment for Explosive Atmospheres - Explosion-Protection

Techniques.

AS 2381

Electrical Equipment for Explosive Atmospheres - Selection, Installation &

Maintenance.

AS 2430

Classification of Hazardous Areas.

IEC79

Electrical Apparatus for Explosive Atmospheres.

SAA HB13

Electrical Equipment for Hazardous Areas (handbook).

A hazardous area is one which has a potentially explosive atmosphere due to combustible

gases, liquids or dusts.  In such an area there has to be a constraint to prevent an electrical

fault from causing an explosion.

For fire detection in hazardous areas there are two main options:

1)

Use approved IS (Intrinsically Safe) detectors and bases with IS isolators or Zener

barriers and approved cabling.

2)

Use approved detectors with explosion proof housings and compatible cabling.  (E.g.

Olsen V41B, (V42B), V44B, T54B).  These are not discussed further in this section

as the constraints are primarily mechanical.

Note that in addition to equipment selection and inter-connection, there are other
requirements for wiring in hazardous areas that must be satisfied.

These include (but are not limited to):

•

  Matching “Ex” rating of equipment chosen with hazardous area classification.

•

  Ensuring cable capacitance and inductance is within the limits of the repeaters used

(see Tables 9.4.3, 9.4.4, 9.4.5 for more details).

•

  Providing adequate physical protection for equipment according to local hazardous

area wiring regulations.

•

  Using cable of the correct insulation and physical strength according to local

hazardous area wiring regulations.

•

  Complying with manufacturer’s instructions for mounting of “Ex” rated devices.

•

  Inspection and certification of the finished installation.