Page no.
19
Comments
There are several symptoms that may detect poor installation or setting of the
QNA-412:
•
The voltage measurements are
flashing
on the display. The causes may be:
−
The equipment has detected an event. This may mean that there has
actually been an event in the line (correct installation) or that the pre-set
nominal voltage does not match that of the system.
−
If the
balance screen displays dashes
: It means that the phase turn
sequence is wrong.
•
Power screens with a minus sign:
−
The installation is generating energy. Or actually, energy is being
generated or the current transformers are installed backwards.
−
The PF values are wrong. Check the voltage phases and current
connection. The voltage and current phase do not correspond to that
connected to the QNA.
8.-
SETTING THE QNA-412.
The QNA-412 is always set via a PC.
The operation of the QNA-412 analyzer will depend on the setting of the
equipment. There are two types of Set-up:
•
Programming Set-up: This will define the QNA-412 analyzer's operating mode.
•
File setup: This will define the variables that the QNA-412 is to record in its
internal memory
8.1.-
Programming Set-up for the QNA-412.
There is a complete series of parameters that may be set in the analyzer:
8.1.1.-
Voltage transformation ratio.
The QNA-412 system analyzer has the option to measure voltage via
transformers.
•
Voltage primary / Voltage secondary:
The voltage transformer ratio via
which the measurement shall be taken can be set. Where direct
measurements are to be made, this must be set as1/1.
•
Current primary:
The current transformer primary used for measuring
current can be set.
•
Neutral current primary:
The current transformer primary used for
measuring Neutral current can be set.
