Name: SE-330AU Series – Neutral-Earthing-Resistor Monitor Series - Littelfuse SE-330AU Neutral-Earthing-Resistor Monitor Provides Superior Protection
Brand: Littelfuse Inc.

SE-330AU Series – Neutral-Earthing-Resistor Monitor Series - Littelfuse SE-330AU Neutral-Earthing-Resistor Monitor Provides Superior Protection

Series: SE-330AU Series – Neutral-Earthing-Resistor Monitor

Questions? Contact Littelfuse Support

Disclaimer Notice

Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation, automotive, military, aerospace, medical, life-saving, life-sustaining or nuclear facility applications, devices intended for surgical implant into the body, or any other application in which the failure or lack of desired operation of the product may result in personal injury, death, or property damage) other than those expressly set forth in applicable Littelfuse product documentation. Warranties granted by Littelfuse shall be deemed void for products used for any purpose not expressly set forth in applicable Littelfuse documentation. Littelfuse shall not be liable for any claims or damages arising out of products used in applications not expressly intended by Littelfuse as set forth in applicable Littelfuse documentation. The sale and use of Littelfuse products is subject to Littelfuse Terms and Conditions of Sale, unless otherwise agreed by Littelfuse. "Littelfuse" includes Littelfuse, Inc., and all of its affiliate entities.

The SE-330AU series is an advanced earth-fault and earthing-resistor monitoring relay for low- and medium-voltage transformers and generators. It monitors neutral current, neutral-to-earth voltage, and neutral-to-earth resistance. It provides continuous monitoring of the neutral-to-earth path to verify that the neutral-earthing resistor (NER) is intact. An open NER renders current-sensing, earth-fault protection inoperative and could result in a false belief that the system is functioning properly.

The SE-330AU earth-fault function complies with AS/NZS 2081.3:2002. Outputs include four relay outputs and an analog output. A mini USB port is included to view measured values, configure settings, and check event records. An on-board micro SD card can be used for long-term data logging. Network communication options are available. For non-AS/NZS 2081 applications, see the SE-330 or SE-330HV.

Resistor Monitoring
The SE-330AU combines the measured values of resistance, current, and voltage to continuously determine that the NER is intact. It is able to detect a resistor failure with or without an earth fault present. Sensing resistors are matched to the system voltage and are used to monitor NGRs on systems up to 35 kV.

Earth-Fault Monitoring
The SE-330AU uses a 5 A or 30 A primary current transformer to provide a pickup-setting range of 0.125 to 5 A or 0.75 to 30 A to comply with AS/NZS 2081.3:2002. DFT filtering ensures that false trips due to harmonic noise from adjustable-speed drives do not occur. Open-CT detection is provided.

Access specifications, certifications, check availability and order parts below

Catalog #	Supply Voltage VAC	Supply Voltage VDC	Relay Contacts Config	Analog Output Current mA	Communications	New Rev Avail	Old Rev Avail	IEEE Device Numbers	Relay Contact Operating	Dimensions	Weight (lbs/g)	Auto Manual Reset	Conformally coated	Frequency	GF Trip Level A	Samples

SE-330AU-00-00	65 - 265	85 - 275	2 Form A; 2 Form C	4 - 20	USB	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-00-01	65 - 265	85 - 275	1 Form A; 1 Form B; 2 Form C	4 - 20	USB	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-01-00	65 - 265	85 - 275	2 Form A; 2 Form C	4 - 20	USB; DeviceNet	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-01-01	65 - 265	85 - 275	1 Form A; 1 Form B; 2 Form C	4 - 20	USB; DeviceNet	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-03-00	65 - 265	85 - 275	2 Form A; 2 Form C	4 - 20	USB; Ethernet (Dual RJ45)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-03-01	65 - 265	85 - 275	1 Form A; 1 Form B; 2 Form C	4 - 20	USB; Ethernet (Dual RJ45)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-04-00	65 - 265	85 - 275	2 Form A; 2 Form C	4 - 20	USB; Ethernet (RJ45 and SC Fiber)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-04-01	65 - 265	85 - 275	1 Form A; 1 Form B; 2 Form C	4 - 20	USB; Ethernet (RJ45 and SC Fiber)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-05-00	65 - 265	85 - 275	2 Form A; 2 Form C	4 - 20	USB; Ethernet (Dual SC Fiber)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-05-01	65 - 265	85 - 275	1 Form A; 1 Form B; 2 Form C	4 - 20	USB; Ethernet (Dual SC Fiber)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-06-00	65 - 265	85 - 275	2 Form A; 2 Form C	4 - 20	USB; IEC61850 (Dual RJ45)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-06-01	65 - 265	85 - 275	1 Form A; 1 Form B; 2 Form C	4 - 20	USB; IEC61850 (Dual RJ45)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-07-00	65 - 265	85 - 275	2 Form A; 2 Form C	4 - 20	USB; IEC61850 (RJ45 and SC Fiber)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-07-01	65 - 265	85 - 275	1 Form A; 1 Form B; 2 Form C	4 - 20	USB; IEC61850 (RJ45 and SC Fiber)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-08-00	65 - 265	85 - 275	2 Form A; 2 Form C	4 - 20	USB; IEC61850 (Dual SC Fiber)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-08-01	65 - 265	85 - 275	1 Form A; 1 Form B; 2 Form C	4 - 20	USB; IEC61850 (Dual SC Fiber)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-20-00	28 - 52	36 - 72	2 Form A; 2 Form C	4 - 20	USB	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-20-01	28 - 52	36 - 72	1 Form A; 1 Form B; 2 Form C	4 - 20	USB	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-21-00	28 - 52	36 - 72	2 Form A; 2 Form C	4 - 20	USB; DeviceNet	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-21-01	28 - 52	36 - 72	1 Form A; 1 Form B; 2 Form C	4 - 20	USB; DeviceNet	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-23-00	28 - 52	36 - 72	2 Form A; 2 Form C	4 - 20	USB; Ethernet (Dual RJ45)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-23-01	28 - 52	36 - 72	1 Form A; 1 Form B; 2 Form C	4 - 20	USB; Ethernet (Dual RJ45)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-24-00	28 - 52	36 - 72	2 Form A; 2 Form C	4 - 20	USB; Ethernet (RJ45 and SC Fiber)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-24-01	28 - 52	36 - 72	1 Form A; 1 Form B; 2 Form C	4 - 20	USB; Ethernet (RJ45 and SC Fiber)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-25-00	28 - 52	36 - 72	2 Form A; 2 Form C	4 - 20	USB; Ethernet (Dual SC Fiber)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-25-01	28 - 52	36 - 72	1 Form A; 1 Form B; 2 Form C	4 - 20	USB; Ethernet (Dual SC Fiber)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-26-00	28 - 52	36 - 72	2 Form A; 2 Form C	4 - 20	USB; IEC61850 (Dual RJ45)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-26-01	28 - 52	36 - 72	1 Form A; 1 Form B; 2 Form C	4 - 20	USB; IEC61850 (Dual RJ45)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-27-00	28 - 52	36 - 72	2 Form A; 2 Form C	4 - 20	USB; IEC61850 (RJ45 and SC Fiber)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-27-01	28 - 52	36 - 72	1 Form A; 1 Form B; 2 Form C	4 - 20	USB; IEC61850 (RJ45 and SC Fiber)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-28-00	28 - 52	36 - 72	2 Form A; 2 Form C	4 - 20	USB; IEC61850 (Dual SC Fiber)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order
SE-330AU-28-01	28 - 52	36 - 72	1 Form A; 1 Form B; 2 Form C	4 - 20	USB; IEC61850 (Dual SC Fiber)	Now	No longer available	50G - 50N - 51G - 51N - 59N - 86	Fail-safe	8.4 H x 3.9 W x 5.8 D in.	0 Kg	Latching; Autoreset	Standard	50; 60; ASD	0.125 - 30.0	Order

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