wtw IQ SENSOR NET System 2020 XT, Руководство по эксплуатации, Страница: 182 / 216

What to do if... System 2020 XT C
ONNECT
10 - 2
ba75970e01 10/2012
10.2.2 Measuring the voltage
If an MIQ module shows an error condition (both LEDs off), this can be
due to the following causes:

The voltage supply has been interrupted

The available voltage is not sufficient; the voltage is below the warn
-
ing range.
These two cases can be differentiated with a voltmeter.
Measuring points of
MIQ modules
The supply voltage is tapped at the following points (Fig. 10-1 on
page 10-3):

Outside on the free contacts on the front of the SENSORNET mod
-
ule

Inside on the SENSORNET connections of the terminal strip (see
section 10.2.2 M
EASURING THE VOLTAGE
).
Measuring points for
IQ sensors
The supply voltage is measured on the MIQ module to which the
IQ sensor is connected via the SACIQ sensor connection cable.
Systematic voltage
measurement
Dock all mobile components (terminals) on the modules with greatest
distance to the next power supply module. Begin measuring the voltage
at the MIQ modules that are directly connected with an MIQ power sup
-
ply module. Continue to measure the voltage systematically to the end
of each cable section, i. e. along the voltage drop. Thus, in combination
with the log book entries, you can narrow down the error location.
WARNING
If the MIQ/PS power supply module is opened during operation, there
is a danger to life due to possible hazard of electric shock. There is also
a danger to life from voltages that may present a hazard of electric
shock on the relay contacts of open MIQ output modules (e.g. MIQ/
CR3). Note the following points in the case of voltage measurement
during operation:

The voltage measurement may not be performed on the open MIQ/
PS power supply module. The MIQ/PS may only be opened when
the line voltage is switched off.

The voltage measurement at an open MIQ output module with re
-
lays may only be performed if all external voltages have been previ
-
ously switched off.

Secure all voltages that have been switched off against being
switched on again for the duration of the work.