TESTO 6681 Instruction Manual page 23

If the channels have to be galvanically isolated, a separate
mains unit must be used for each channel.
Wiring diagram for 4-wire system
(0 to 20 mA/4 to 20 mA/0 to 1 V/0 to 5 V/0 to 10 V)
20 to
30V
AC/
DC
0 V
Requirement for the connecting cable of the supply:
•
•
•
1 Feed connection cables of the two, or optionally three, channels
through opened M 16 x 1.5 screw connection (item (8) in Overview of
terminals, chapter 1.3.2.1).
2 Strip the cable ends, clamp wire end ferrules on and screw to channel
terminals as shown in diagram.
3 Close M 16 x 1.5 screw connection (item (8) in Overview of terminals,
chapter 1.3.2.1).
Insulated with cross-section of at least 0.25 sq. mm.
The supply line must be secured against exceeding 8 A.
An OFF switch must be installed in an easily accessible
position close by and be marked as such.
testo 6681
2 or 3 channels
0 to 20 mA/
4 to 20 mA/
max. load per 500 Ω
0 to 1 V/0 to 5 V/0 to 10 V
- 1.3 Commissioning 23