9
3.3. Explosimetric detectors
•
Only explosimetric detectors of the "bridge" type can be connected to the S4B.
The detector must be of type CAPTEX, CEX300, CEX800 or CEX810.
•
Surveyor 4B and the detector are connected together by a shielded cable with three active
conductors. The shielded cable is to be connected to the earth at one end only.
•
Terminals C1, C2 and C3 of Surveyor 4B and the detector are to be connected in opposite mode
(see Fig. 3).
•
The maximum loop resistance is 1.4 ohms.
For example: the ma ximum distance between Surveyor 4B and the detector will be 40 m with
conductors with a cross section of 1.5 mm².
•
In some cases, Surveyor 4B can be fitted with two explosimetric detectors via an
interconnection box. This box must always be placed as near as possible to the two detectors and
the maximum distance is determined by the following formula:
MAX. distance = L1 +2 (L2 + L3)
3
2
1
Detector terminal
FIGURE 3
4 conductors
"CAPTEX" detectors, for example
JUNCTION BOX
L1
L 2
L 3
FIGURE 4
4 conductors
3 conductors
Detector 2
Detector 1
