8
Sensor leads
Sensor terminal diagram
Sensors are always connected across the relevant sensor terminal (
S1 – S6
) and sensor earth
(GND).
In order to prevent measurement fluctuations and ensure perfect signal transmission, sensor leads
must not be subject to external negative influences through 230 V cables.
Never run sensor leads together with mains voltage cables in the same conduit.
When using non-screened cables, route sensor leads and 230 V cables either in separate cable con
-
duits or with a minimum clearance of 5 cm.
Sensor leads for PT100 or PT500 sensors must be screened.
If screened cables are used, the screen must be connected to the sensor earth (GND)
All sensor leads with a cross-section of 0.5 mm2 can be extended to up to 50 metres. With this lead
length and a PT1000 temperature sensor, the measuring error is approxi1 K. A correspond
-
ingly larger cross-section is required for longer leads or a lesser measuring error.
The connection between the sensor and the extension can be made by pushing heat shrink tubing
(trimmed to 4 cm) over one core and twisting the bare wire ends. Solder the connection if one of the
wire ends has been tin-plated.
Then push the heat shrink tubing over the connection and heat up carefully (e.g. with a lighter) until
it sits tightly over the connection.
