Oldham MX 52, Installation Manual, Page: 9 / 48

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1.3.2. 3-wire detectors 4-20 mA: 3 connecting wires for shielded cable
- Resistance of detector / unit cable: 16 ohms maximum per wire, i.e. 32 ohms in
loop (1 km for cable 3 x 1.5 mm²).
- Connection on MX52 unit: see Fig. 10.
1.3.3. 2-wire detectors 4-20 mA: 2 connecting wires for shielded cable
- Resistance of detector / unit cable: 32 ohms maximum per wire, i.e. 64 ohms in
loop (2 km for cable 2 x 1.5 mm²).
-
Connection on MX52 unit: see Fig. 11.
1.3.4. FIRE detectors: 2 connecting wires for shielded cable
The current commercial designations are as follows:
-
“Thermovelo” detectors of type EC 11 (sensitive to temperature variations)
- Ionic detectors of type EI 1 100 (sensitive to smoke)
- Optical detectors of type EO 1 100 (sensitive to smoke)
- Resistance of detector / unit cable: 28 ohms maximum per wire, i.e. 56 ohms in
loop (2 km for cable 2 x 1.5 mm²)
- Fire detectors can be detected in parallel to a maximum of five. The end-of-loop
resistor (2.7 K) is to be placed at the end of the line on the last detector.
- Connection on MX52 unit: see Fig. 11
1.3.5. FLAME detectors: 2, 3 or 4 connecting wires for shielded cable
depending on utilization
REMARK
The detectors can be supplied with power either via the MX52 unit or by an auxiliary 24 V
DC source.
These detectors can operate in standalone mode:
24 V DC power supply and direct utilization of relay contacts in accordance with the technical
specification corresponding to the detector used.