• The maximum loop resistance is 1.4 ohms.
For example: the maximum distance between Surveyor 4B and the detector
will be 40 m with conductors with a cross section of 1.5 mm².
External components
Surveyor 4B is equipped with the following two relays:
• Relay 1 (REL 1), which is in mode, corresponds to the first gas alarm
threshold and to the "FAULT" alarm.
This relay is equipped with SPDT contacts available on the SV 4B
terminal block (Item 3, Figure 4).
• Relay 2 (REL 2), which is "negative safety" mode, corresponds to the
second gas threshold only. This relay is also equipped with SPDT
contacts available on the SV 4B terminal block (item 4, Figure 4).
• These both relays could be configured in positive and negative
security (programmation by welding slots on the printed circuit board:
made only by OLDHAM or a skilled personal).
N.B. : The relay contacts are dry contacts, corresponding to the appliance
without power supply.