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.

Features and Benefits

Continuous NGR monitoring	Detects resistor failure within seconds, reduces transient-overvoltage risk, removes risk of ground-fault-detection failure
Shorted NGR detection	Detects a ground fault on the neutral that could bypass the resistor, ensures fault current is not higher than expected
Ground-fault detection	Main or backup protection to detect a ground fault anywhere on the monitored system
Adjustable pickup (2-100%)	Select greatest sensitivity without false operation, adjustable in 1% increments (MEM setting)
Adjustable time delay (0.1 - 10 s)	Adjustable trip delay allows quick protection and system coordination
Universal CT compatibility	Allows the use of a CT that gives required ground-fault settings
Programmable output contacts	Two programmable Form C and One programmable Form A (Ground Fault, Resistor Fault, Unit Health)
Selectable contact operating mode	Selectable fail-safe or non-fail-safe operating modes allows connection to shunt or undervoltage breaker coil or alarm circuit (K1, K2, and K3 output contacts)
Analog output (4 - 20 mA)	Connect an optional PGA-0520 meter or control system
Pulsing output (SE-330 only)	Control the operation of a pulsing ground-fault-location circuit
Trip records	On-board 100-event (with date and time) recorder helps with system diagnostics
Harmonic filtering (DFT)	Eliminate false trips due to harmonic noise from ASDs
Local communications	Mini USB port to view measured values, configure settings, and check event records
Data logging	On-board microSD card (included) can be used for long-term data logging
Network communications	Remotely view measured values and event records, reset trips, and cause a remote trip Available Protocol Options: IEC 61850 - with dual RJ45, SC Fiber and RJ45, or Dual SC Fiber Interface Modbus TCP and Ethernet/IP - with dual RJ45, SC Fiber and RJ45, or Dual SC Fiber Interface DeviceNet - with CAN interface
Software	PC-interface software (SE-MON330) is available at Littelfuse.com/RelaySoftware
Selectable reset mode	Selectable latching or auto-reset operation
Unit-healthy output	Verifies SE-330 is operating correctly, available as Form A or Form B output contact
Conformal coating	Internal circuits are conformally coated to protect against corrosion and moisture

Documents and Downloads

Document	File Type	File Size	Download
SE-330, SE-330HV SERIES Datesheet	PDF	435 KB