Controlled Installation Instructions


Intrinsically safe sensor with a RS 232 safety barrier Division 1 Applications

 

 

WARNING – SUBSITUTION OF COMPONENTS MAY IMPAIR INTRINSIC SAFETY.

WARNING – TO PREVENT IGNITION OF FLAMMABLE OR COMBUSTIBLE ATMOSPHERE, DISCONNECT POWER BEFORE SERVICING.

 

AVERTISSEMENT: LA SUBSTITUTION DE COMPOSNATS PEUT COMPROMETTRE LA SÉCURITÉ INTRINSÈQUE.

AVERTISSEMENT: AFIN DE PRÉVENIR L’INFLAMMATION D’ATMOSPHÈRES, POUR SERVICE – DÈBRANCHEZ L’PUISSANCE

 

NOTES:

 

1. Associated apparatus must be installed in accordance with its manufacturer’s control drawing and with the National Electrical Code, NFPA 70, Article 504 and ANSI/ISA – RP 12.2.02 – 1996 or Section 18 of the Canadian Electrical Code for installations in Canada.

 

2. Associated apparatus output current must be limited by a resistor such that the output voltage-current plot is a straight line drawn between open-circuit voltage and short-circuit current.

 

3. Selected associated apparatus must be third party listed as providing intrinsically safe circuits for the application as shown in Table 1.

 

4. Capacitance and inductance of the field wiring from the intrinsically safe equipment to the associated apparatus shall be calculated and must be  included in the system calculations as shown in table 1. Where the cable capacitance and inductance per foot are not known, the following values shall be used:

 

 Ccable = 60 pF/ft., (Ex: Ccable = 1000ft x 60 pF/ft = 60 nF)

 Lcable = 200 nH/ft, (Ex: Lcable = 1000ft x 200 nH/ft = 0.2 mH)

 

            TABLE 1:         

            I.S. Equipment               Associated Apparatus

            V max (or Ui)     ³          Voc or Vt (or Uo)

            I max (or Ii)        ³          Isc or It (or Io)

            P max (or Pi)     ³          Po

            Ci + Ccable       £          Ca (or Co)

            Li + Lcable        £          La (or Lo)

 

     If Po of the associated apparatus is not known, it may be calculated using the formula Po = (Voc*Isc)/4 = (Uo*Io)/4.

 

5. Associated apparatus must not be used in combination unless permitted by the associated apparatus certification.

 

6. Control equipment must not use or generate more