PTE-50-CET
Sheet 38
When this key
is pressed again, the step will be the opposite, that 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: current (from 0.1 A up to 25 A) or voltage
(from 5 V up to 300 V), with frequencies between 40 and 70 Hz. 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.
In case this reference signal is not proper, the unit will be synchronized to the last valid reference.
4.4.
GENERAL CONTROL SECTION
The general control section is intended to acts as an interface between the unit and other PTE units,
extern printer, computer, and detects the answer from the under testing relay through the Signal
Monitor. All these functions are described below.
4.4.1. SIGNAL
MONITOR
It is designed to receive the signals from the relay being tested and the status is shown in the LED
indicator marked “MONITOR”.
The
Signal Monitor
is activated (LED monitor lights up) in one of the following conditions:
