Electrical connections
24 TTF300
OI/TTF300-EN
5.5.1 Standard
application
Field Control
room
A
B
+
-
U
M
+
U
S
-
R
Ltg
A00094
Fig. 9
A Transmitter
B Power supply / SPS input with supply
When connecting transmitters and power supplies, observe the following specification:
U
Mmin
≤
U
Smin
+ 0.02A x R
Ltg
Where
U
Mmin
:
Minimum operating voltage of transmitter (refer to technical data for transmitter)
U
Smin
:
Minimum supply voltage of power supply / SPS input
R
Ltg
: Line resistance between transmitter and power supply
For HART functionality, use power supplies or SPS input cards with HART mark. If this is not
possible, the interconnection must have a resistance
≥
250
Ω
(< 1100
Ω
).
The signal line can be connected with or without ground. When connecting the ground (minus
side), make sure that only one side of the contact is connected to the equipotential bonding
system.
