User's Manual

PC Software for 1740 Series

PQ Log Feature Reference

Note

An exceeding occurs when the mean measured value Plt (according to the

EN 50160 standards, the mean value Plt is calculated over twelve

10 minute mean values Pst) is above or below the limit value. The standard

is met if 95 % of all measured values are below the limit value.

Voltage Unbalance

This option indicates the limit value for permissible voltage unbalance in three phase

systems.

Note

An exceeding occurs if the measured mean value (according to the EN-

50160 standard, the 10 minute mean value) is above the limit value. The

standard is met if 95 % of all measured values are below the limit value.

Number of Allowed Events

Determines the permissible number of events. The standard does not prescribe a value.

The default value is 100 events during one week.

Interruption Limit

Allows you to define the threshold for interruptions in % of V

. A dip below this value

will be considered an interruption.

Interharmonics

Opens the Limit value level file - Interharmonics screen. It indicates the limit values for

interharmonics.

Voltage Harmonics

Opens the Limit value level file - Voltage Harmonics screen. It indicates the limit values

for harmonics and the thd.

Current Harmonics

This function is similar to voltage harmonics. This button opens the “Limit value level

file – Current Harmonics” screen. Limit values for individual current harmonics and the

thd can be defined in this screen.

Tip for Central European Distribution Networks

A very important task for utilities is to assess the additional network distortion produced

by new consumers which are to be connected to the network.

There are clearly defined emission levels for each single current harmonic to further

ensure safe and correct operation of all consumers in the network without any failures.

There is a recommendation issued by experts of the Austrian E-CONTROL, the Austrian

VEÖ, the Swiss VSE, the German VDN and the Czech CSRES, which prescribes a

procedure for assessing the impact of new appliances to the distribution network which

can be carried out easily with the Logger product range with the measuring function A.

The Procedure in General:

For a specific installation there are some parameters which provide us with the relevant

basic information: