Description
SE-330-00-00 is an advanced ground-fault and neutral-grounding resistor monitor with a supply voltage ac of 65–265 and a supply voltage dc of 85–275. Network communications is offered via USB.
Description
The SE-330 is an advanced ground-fault and neutral-grounding-
resistor monitoring relay that is compliant with Rule10-302 of the
2018 Canadian Electrical Code Part I (CE Code). It measures neutral
current, neutral-to-ground voltage, and neutral-to-ground resistance.
It provides continuous monitoring of the neutral-to-ground path to
verify that the neutral-grounding resistor (NGR) is intact and that it
has not been bypassed or shorted. An open NGR renders current-
sensing ground-fault protection inoperative and could result in a false
belief that the system is functioning properly. A shorted NGR results
in higher-than-expected ground-fault current. The SE-330 can be used
with low- and medium-voltage transformers and generators with
low- or high-resistance grounding used in processing, manufacturing,
chemical, pulp and paper, petroleum, and water-treatment facilities.
For high-voltage applications, use the SE-330HV. For applications that
require conformance to Australian standards, use the SE-330AU.
Resistor Monitoring
The SE-330 combines the measured values of resistance, current,
and voltage to continuously determine that an NGR is intact. It is
able to detect an open or shorted resistor with or without a ground
fault present. Sensing resistors are matched to the system voltage
and are used to monitor NGRs on systems up to 72 kV.
Ground-Fault Monitoring
The SE-330 uses an application-appropriate current transformer to
reliably detect ground-fault currents as small as 100 mA. Discrete-
Fourier Transform (DFT) filtering ensures that false trips due to
harmonic noise from adjustable-speed drives do not occur. Should
the resistor open and a ground fault subsequently occur, the SE-330
will detect the fault through voltage measurement, while other
current-only sensing relays would be ineffective.
Pulsing Ground-Fault Location
The SE-330 is capable of controlling a pulsing contactor, which is
used to switch the NGR resistance in a pulsing-compatible NGR
package. The resulting ground-fault current is distinguishable from
charging currents and noise and will only appear upstream of the
ground fault, making fault location fast and easy, even without
isolating feeders or interrupting loads