Connecting The Device - Siemens 7MF8.23 Series Compact Operating Instructions

CAUTION
Ambient temperature too high
Damage to cable sheath.
● At an ambient temperature ≥ 60 °C (140 °F), use heat-resistant cables suitable for an ambient temperature at least 20
°C (68 °F) higher.
CAUTION
Incorrect measured values with incorrect grounding
The device must not be grounded via the "+" connection. It may otherwise malfunction and be permanently damaged.
● If necessary, ground the device using the "-" connection.
Note
Electromagnetic compatibility (EMC)
You can use this device in industrial environments, households and small businesses.
For metal housings there is an increased electromagnetic compatibility compared to high-frequency radiation. This
protection can be increased by grounding the housing, see section "Connecting the device (Page 16)".
Note
Improvement of interference immunity
● Lay signal cables separate from cables with voltages > 60 V.
● Use cables with twisted wires.
● Keep device and cables in distance to strong electromagnetic fields.
● Use shielded cables to guarantee the full specification according to HART.
● Connect a load resistor of at least 230 Ω in series in the signal circuit in order to guarantee fault-free HART
communication. When power supply isolators are used for HART transmitters, e.g. SITRANS I, a load resistor is already
installed in the device.

Connecting the device

Opening the device
1. Unscrew the cover of the electrical cable compartment.
2. Unscrew the cable gland cover and remove the plastic seal.
Connecting the device
Note
The following values can be set for the load:
● 230 to 1100 Ω for the HART communicator
● 230 to 500 Ω for the HART modem
16
SITRANS P300 (7MF8.23.. 7MF8.24.. 7MF8.25..)
A5E03434761-01, 08/2011