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SE-330, SE-330HV SERIES (PGR-5330)

SE-330, SE-330HV SERIES (PGR-5330)
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Littelfuse* Expertise Applied | Answers Delivered Protection Relays & Controls Neutral-Grounding-Resistor Monitoring Neutral-Grounding-Resistor Monitor - Previous Revision Simplified Circuit Diagram Description The SE-330 is an advanced ground-fault and neutral-grounding-resistor monitoring relay. 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. This is of utmost importance—an open NGR renders current-sensing ground-fault protection inoperative and could result in a false belief that the system is functioning properly. 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 standard AS/NZS 2081.3:2002, see the SE-330AU. Resistor Monitoring The SE-330 combines the measured values of resistance, current, and voltage to continuously determine that the NGR is intact. It is able to detect a resistor failure 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. 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. Ordering Information For detailed wiring diagram, see adjacent page. 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. Accessories ER Series Sensing Resistor Required interface between the power system and the /wwHV. Eliminates hazardous voltage levels at the relay. EFCT Series Ground-Fault Current Transformer Sensitive ground-fault current detection (5 A primary). SE-CS30 Series Ground-Fault Current Transformer Sensitive ground-fault current detection (30 A primary). Other Current Transformer For low-resistance NGRs choose a CT primary approximately equal to the NGR rating. Littelfuse reserves the right to make product changes, without notice. Material in this document is as accurate as known at the time of publication. Visit Littelfuse.com for the most up-to-date information. © 2014 Littelfuse Protection Relays & Controls Littelfuse.com/se-330 Littelfuse.com/se-330hv Rev: 4-E-112513 Based on SE-330 Manual Rev: 9-A-112913 Based on SE-330 HV Manual Rev: 4-A-112913

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Littelfuse* Expertise Applied | Answers Delivered Protection Relays & Controls Neutral-Grounding-Resistor Monitoring Neutral-Grounding-Resistor Monitor - Previous Revision FEATURES IEEE # BENEFITS Continuous NGR monitoring Ground-fault detection Detects resistor failure within seconds, reduces transient-overvoltage risk, removes risk of ground-fault-detection failure Main or backup protection to detect a ground fault anywhere on the monitored system Adjustable pickup (2-100%) Adjustable time delay (0.1-10 s) Universal CT compatibility Output contacts Analog output (4 - 20 mA) Pulsing output...

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