PTE-300-V
Sheet 36
4.3.2. DYNAMIC TESTS: STEP TO 2
ND
VALUE
The PTE-300-V allows the operator to make dynamic tests, by allowing jumps (steps) from one value
to another, whether it is from higher to lower or vice versa. This is very useful, for example, when
testing out-of-step generator protective relays. This is achieved as follows:
1. Press the key
. In the display will appear the reading “0000” or the 2
nd
value previously
recorded. Select with the rotating knob the desired value to acts as 2
nd
value.
2. Press again the key
. The display will show the actual value that is the 1
st
value. Turn
on the output if this is off.
3. Press the key
. This will produce instantaneously the step from the actual value to the
2
nd
selected value. At the same time there is a signal sent to
Start Chrono
output, to start an
external timer if desired. Furthermore, the LED located above this press key indicates that the
2
nd
value is in the output.
IMPORTANT: When the unit is in this situation the displayed
phase angle cannot be changed even if the rotating knobs are turned.
When this key
is pressed again, the step will be the opposite, which is from the 2
nd
value
to the 1
st
one. At the same time, there is a signal sent to
Start Chrono
output. The LED will go off
indicating the output is at the 1
st
value.
NOTA: You can select a 2
nd
value even when the corresponding output is on. In this
situation, though the display is not showing the actual output value, this remains
in the output.
4.3.3. USE OF EXTERNAL REFERENCE INPUT
The
External Reference
input admits two types of signal with frequencies between 40 and 70 Hz:
current (from 0.1 A up to 25 A) or voltage (from 5 V up to 300 V). This input is very useful as it allows
the unit to work in a differential mode respect to the signal inputs. Because of the wide range of input
values in both voltage and current, it is capable to work with various types of supply generators for a
signal reference.
The current input should be connected to the black tap marked “0” and the green tap marked 0.1 - 25
A. The voltage input should be connected to the black tap marked “0” and the red tap marked 5 - 300
V.
IMPORTANT NOTE
: The current input has low impedance SHUNT detector. NEVER connect a
voltage signal to this tap, as it is equivalent to short-circuit. It may cause
serious damage to the external voltage supply if it is not protected.
When
External Reference
is selected as reference source in the unit (Ext.), if it is valid, the LED
located to the left hand of (0) tap will light up.
