Littelfuse SE-330AU Series - Manual

Protection Relays & Controls
© 2013 Littelfuse Protection Relays & Controls
Littelfuse.com/se-330au
Description
The SE-330AU 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. This is of utmost importance—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, an analog output, and an RS-232 interface.
Network communications 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- 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.
SE-330AU SERIES
Neutral-Earthing-Resistor Monitor
Simplified Circuit Diagram
NER
L2
CT
L1
SE-330AU
SERIES
ER SERIES
(Sensing Resistor)
(NER Monitor)
A
B
ORDERING
NUMBER
COMMUNICATIONS
CONTROL
POWER
SE-330AU-00-0X RS-232 120/240 Vac/Vdc
SE-330AU-01-0X RS-232 & DeviceNet ™ 120/240 Vac/Vdc
SE-330AU-02-0X RS-232 & Profibus ® 120/240 Vac/Vdc
SE-330AU-03-0X RS-232 & EtherNet /IP & Modbus TCP 120/240 Vac/Vdc
NOTE: For 48 Vdc Control Power use part numbers SE-330AU-20-00, SE-330AU-21-00,
SE-330AU-22-00 or SE-330AU-23-00 respectively.
Ordering Information
ACCESSORIES REQUIREMENT
ER Series Sensing Resistor Required
Current Transformer Required
SE-IP65CVR-G Optional
SE-MRE-600 Optional
RK-332 Optional
Specifications
Input Voltage 80 to 265 Vac/Vdc or 36 to 72 Vdc
Dimensions H 213 mm (8.4”), W 98 mm (3.9”), D 132 mm (5.2”)
GF Trip-Level Settings 0.125 to 30 A
GF Trip-Time Settings 0.1 to 0.5 s
Vn Trip-Level Settings 20-2,000 Vac (≤5 kV systems)
100-10,000 Vac (>5 kV systems)
Output Contacts Two Form A, Two Form C
Operating Mode Fail-Safe
Harmonic Filtering Standard feature
Reset Front panel push button and remote input
Approvals CSA certified; C-Tick ( Australian )
Communications RS-232; (standard) DeviceNet ™ , Profibus ® ,
Ethernet (optional)
Analog Output 4-20 mA, self or loop powered
Conformal Coating Standard feature
Warranty 5 years
Mounting Panel, Surface (optional)
Neutral-Earthing-Resistor Monitoring
Rev: 4-B-050213
Based on Manual Rev 3
ER Series Sensing Resistor
Required interface between the power system
and the SE-330AU. Eliminates hazardous voltage
levels at the relay.
EFCT Series Earth-Fault Current Transformer
Sensitive earth-fault current detection (5 A primary).
SE-CS30 Series Earth-Fault Current Transformer
Sensitive earth-fault current detection (30 A primary).
Accessories
A
B