РА1.007.001РЭ-001
16
PARMA Ltd.
Figure 7
6.2.5 Measurement of current-current phase shift
6.2.5.1
To measure current-current phase shift (only for the de-
vices completed with two clamps), connect reference clamp (see fig. 8) to
connector marked with Ireference. Join measuring clamp to connector
marked with Imeasuring. Use them for their designated purpose, as they are
not interchangeable. Clamps are marked for correct orientation related to
source (generator) of current. In case of false orientation additional phase
shift will be measured.
6.2.5.2
Embrace the wires with a clamp and make sure that it is
fixed well. Since the moment of signal appearance from clamp of the refer-
ence channel (Ireference) the device will be switched to the proper mode
automatically. The lower line will display the value of phase shift between
Ireference and Imeasuring. Read the indication from the lower line of display,
prefix of current-current phase shift:
ii=;
Figure 8
6.2.6 Measurement of current-voltage phase shift
6.2.6.1
To measure current-voltage phase shift, connect reference
clamp to connector marked with Ireference (see fig. 9).
6.2.6.2
Apply voltage to terminals, marked as Uref. Since the mo-
ment of signal appearance from clamp of the reference channel (Ireference)
the device will be switched to the proper mode automatically. The upper line
─190.0W
220.0V
29.2var 999 mА
180°
270°
0°
90°
Uc
Ia
150°
φiu= ?°
0.0V
φii= 30° С 999 mА
180°
270°
0°
90°
Ic
Ia
30°
РА1.007.001РЭ-001
13
PARMA Ltd.
4.7.2.2
The device consists of two galvanically separated parts:
reference and measurement channels.
4.7.2.3
The reference channel is intended for formation of signals
necessary for measurement of phase shifts of galvanically isolated circuits.
These may be current (Im) or voltage (Um). The reference channel consists
of three comparators (1,2,3); two of them to form reference signals Im and
Um (1,2) and one (3) to work with voltage signal Ub in the mode of determi-
nation of phase alternation order. Comparators convert the input sinusoid
signal to meander and pass it through opto-isolators (9) to micro-controller
(10) for further processing. Comparators’ supply is provided by isolated volt-
age converter (4).
4.7.2.4
The measurement channel apart from similar signal forma-
tion facilities for phase shift determination (7,8) contains two voltage-to-
frequency converters (5,6) used for direct measurement of current and volt-
age values.
4.7.2.5
All formed signals come to micro-controller (10), where
programmed evaluation and operation mode choice is made based on de-
termined priorities (see below). The results of measurements are taken out to
display (11).
4.7.2.6
The display has lighting controlled by timer (12) set on 10
sec, which can be started by a button (13).
4.7.2.7
Power supply of measurement channel is provided by the
device (14), forming voltage b5 V and –5 V.
5
PREPARATION FOR USAGE
5.1
For device power supply use 4 galvanic elements of the type,
mentioned in p. 4.3 with total voltage of 6 V. Use of analogues is permissible.
To install power supply battery unscrew the screws on the back side of the
device and install 4 elements in accordance with marking on the cover of
battery section.
5.2
The device maintains serviceability in case of deep discharge
of the battery without sufficient increase of measurement error. The feature
of necessity to change a battery is a sharp decrease of display contrast
range or its flicker.