Page 25
SE-330
Neutral-Grounding-Resistor
Monitor
Rev.
9-A-112913
3.5 P
ULSING
C
ONNECTION
Set switch S1 to K1 = PULSING and use an external
switch as shown in Fig. 21 to use relay K1 to control a
pulsing contactor. Relays K2 and K3 can be used for
tripping; however, they operate in the non-fail-safe mode
only.
TO SENSING
RESISTOR
TERMINAL N
NEUTRAL
NGR
NOTE 1
L
22
23
C
N
K1
SE-330
NOTE 2
16
17
PULSE
ENABLE
NOTES:
1. ALTERNATE NGR CONFIGURATION.
2. SET SWITCH S1 TO K1 = PULSING.
FIGURE 21. Simplified Pulsing Connection.
4. C
OMMUNICATIONS
4.1 L
OCAL
C
OMMUNICATIONS
P
ORT
The SE-330 has an RS-232 communications port
which is designed for use with firmware-upgrade and
system-monitoring software running on a PC.
The RS-232 port is non-isolated and operates as a
DCE device with the connector (socket contacts) pin-out
listed in Table 3. This port allows direct connection to a
PC using standard DB-9 connector cables. Cable length
should not exceed 10 metres.
TABLE 3. RS-232 DB-9 T
ERMINALS
P
IN
#
S
IGNAL
N
AME
C
OMMENTS
1 DCD
470
connected to +12 V
2
RD
Output to DTE from SE-330
3
TD
Input from DTE to SE-330
4 DTR
Not
connected
5 SG
Signal
Ground
6 DSR
470
connected to +12 V
7 RTS
Not
connected
8 CTS
470
connected to +12 V
9 RI
Not
connected
4.1.1 L
OCAL
D
ATA
A
CQUISITION
The SE-330 outputs a data packet every second. Data
output is in the standard UART data format of eight data
bits and one stop bit. The baud rate is fixed at 38,400
bits per second. Use PC program SE-MON330 to
display the following data:
SE-330 settings and switch states.
Neutral voltage and current.
Resistance change.
Trip status.
Pending trips.
Relay and LED status.
NGR calibration value.
- Expected 20-k
value: R
NGR
to (R
NGR
-300)
- Expected 100-k
value: R
NGR
to (R
NGR
-4,000)
Firmware revision level.
The last ten trip records. Each record contains the trip
cause and the pre-trip NGR current, voltage, and
resistance values.
Data can be logged to a PC file at user-defined time
intervals for future analysis.
4.1.2 L
OCAL
C
OMMUNICATIONS
C
OMMANDS
As of firmware revision 10, the SE-330 supports event
record commands through the local RS-232
communications port. Commands are input as standard
ASCII characters. The latest revision of SE-MON330
supports the following commands:
‘d’ – Read event records.
‘c’ – Clear event records
4.1.3 F
IRMWARE
U
PGRADE
The local port can be used to upgrade the SE-330
firmware. Upgrade procedure:
1) Remove supply voltage.
2)
Set switch S8 to UPGRADE.
3)
Apply supply voltage. The DIAGNOSTIC LED
will be on and all relays will be de-energized.
4) Run SE-FLASH and follow the instructions.
5) Remove supply voltage.
6) Set switch S8 to RUN.
7) Apply supply voltage.
SE-MON330 and SE-FLASH are available at
www.littelfuse.com/protectionrelays.
4.2 N
ETWORK
C
OMMUNICATIONS
The SE-330 interface for optional communications
modules supports DeviceNet™, PROFIBUS
®
, and
Ethernet:
DeviceNet™:
DeviceNet Slave.
DeviceNet specification Vol 1:2.0, Vol 2:20.
