VEGA VEGASTAB 690 - Manual (Page 10)

10 VEGASTAB 690
5 Diagnostics
5.1 Maintenance
The instrument is maintenance-free.
5.2 Repair
For safety and warranty reasons, any internal
work on the instruments, apart from that
required in normal installation and connection,
must be carried out only by VEGA personnel.
In case of defect, please return the respec-
tive instrument with a short description of the
fault to our repair department.
Diagnostics
1 2 4 3
+ – + –
+ – + –
1
+ 2
–
mA
1
2
5.3 Checking the measuring cable
A measuring instrument connected to the
interlock sockets is switched without interrup-
tion into the circuit of the measuring cable
(series connection). This enables diagnostic
checking of the measuring cable. The
measuring instrument shows the actual
current.
The same procedure is also valid for output
2, measuring cable 2 on the interlock sockets
2.
Sensor
e.g. VEGADIS
e.g.
DCS
VEGASTAB 690
power supply unit
Measuring instrument
load max. 15 Ohm
Note!
In Ex systems make sure that the Ex protec-
tion is not degraded by the measuring instru-
ment.