Isolator/Barriers - Vaisala K-PATENTS PR-23 Series Instruction Manual

9 Sensor specifications
Notes:
In the United States, installation must be in accordance with the applicable require-
ments of ANSI/ISA RP12.6 and the national electrical code (ANSI/NFPA 70). In
Canada installation must be in accordance with the applicable requirements of Cana-
dian electrical code part I C22.2.1 section 18 and appendix F. Associated Apparatus
manufacturer's installation drawing shall be followed when installing this equipment.
Ex ia is defined as Intrinsically Safe. The intrinsic safety concept allows the intercon-
nection of two intrinsically safe devices. FM approved and CSA certified entity para-
meters are not specifically examined in combination as a system when:
Uo or Voc or Vt <= Vmax,
Io or Isc or It <= Imax
Ca or Co >= Ci + Ccable or
La or Lo >= Li + Lcable, Po < Pi.
Control equipment connected to the Associated Apparatus shall not use or generate
more than 250 Vrms or Vdc. Important: Use supply wires suitable for 5 K above
surrounding environment.
For Division 1 installations, the configuration of Associated Apparatus shall be FM
Approved/CSA Certified under Entity Concept.
Cables for intrinsically safe installation:
– 10 m (33 ft) cable, part number PR-8230-010, connecting the Indicating transmit-
ter STR and the Isolator unit.
The maximum cable length is 100 m (330 ft).
– 10 m (33 ft) power cable, part number PR-8250-010, connecting the Indicating
transmitter STR and the Isolator unit, part number PR-8250-010. The maximum
length is 100 m (330 ft).
– The intrinsically safe cable between Isolator unit and sensor, part RP-8260-xxx,
where xxx is the cable length in meters. The maximum length is 200 m (660 ft).
For cable connections see Figures 9.38 and 9.40.
Note: Isolator/Barrier Unit can also use an optional external +24V DC power supply
instead of the +24V DC power supply from the transmitter. +24V DC is connected to
terminals 13 and 14. (If +24V DC is used, the PR-8250 power cable is not used at all.)

9.11.3 Isolator/barriers

Isolator unit wiring is explained below in Figure 9.40.
Note: If the power to Isolator unit terminals is not correctly connected, +24V DC to
terminal 14 (+vs) and zero to terminal 13 (-vs), the transmitter STR will give the mes-
sage . Also if terminals 11 and 12 are not correctly connected, sensor cable
No signal
connecting terminal 2 of the Indicating transmitter STR to the Isolator unit terminal
11 (-ve) and terminal 1 of the STR to Isolator unit terminal 12 (+ve) , the message
will appear.
signal
143
No