K-Patents PR-23 - Manual (Page 143)

9 Sensor specifications 135
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.
2 1 3 5 4 6 8 7 9 11 10 12
13
14
+ve -ve +ve -ve
-vs
+vs
ISOLATOR UNIT
24VDC
Power cable
PR-8250-xxx
(max 100m)
(max 100m) (max 200m)
Cable
PR-8230-xxx
1
2
Cable
PR-8260-xxx
Figure 9.40 Isolator unit wiring
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
No signal . Also if terminals 11 and 12 are not correctly connected, sensor cable
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
No
signal will appear.