EA Technology UltraTEV Monitor, Operating Manual

Page: 29 / 112

EA Technology UltraTEV Monitor
TM
Operating Manual 2178L014
26
4.2.3 Ultrasonic Contact Probe
In some instances there is no direct air path between the PD
source and the instrument for ultrasonic signals to pass along. In
such cases the UltraTEV Monitor Contact Probe should be used to
detect ultrasonic signals inside these sealed enclosures. It clamps
onto a ferrous surface using built in magnets.
4.2.4 Cable PD Sensor
The cable PD sensor is a Radio Frequency Current Transformer
(RFCT). When installed around the earth connection or strap
between the cable sheath and the earthed switchgear, it allows the
high frequency current transients that are generated by PD activity
within the cable or cable joints to be detected. The RFCT detects
partial discharge pulses in the range of 200 kHz to 20MHz.
A single cable PD sensor may be connected to each Node.
EA Technology RFCTs are designed to be installed by suitably competent
operators on cable earth/ground straps which are suitably and efficiently
connected to earth/ground to maintain safety.
RFCTs, connecting leads and test equipment do not provide protection
against high voltage.
4.2.5 External Temperature/Humidity Sensor
It has been shown that stratification of the air within substation
environments can lead to variations in relative humidity,
therefore the UltraTEV Monitor allows multiple temperature and
humidity sensors to be connected, one per Node. The sensor
plugs into the socket on the top face of the Monitor. It can be
mounted onto ferrous surfaces using the integral magnetic
mount or tie wrapped in place.