BECKWITH ELECTRIC M?3311A, Instruction Book

Page: 12 / 450

–11–
M‑3311A Transformer Protection Relay
Sequence of Events Log
The Sequence Events Log records predefined relay events. The Sequence of Events Log includes 512 of the
most recently recorded relay events. The events and the associated data is available for viewing utilizing the
S-3300 IPScom Communications Software. The sequence of events log is stored in RAM and will be erased
if power to the relay is removed.
Through Fault Recorder
In addition to the Even Recorder, the M-3311A also has a separate Through Fault Recorder, which records
Through Faults. Each through fault record contains the serial number of the fault, duration of the event, maximum
RMS fault current magnitude for each phase during the fault,
I
2
t and the time stamp of the fault. In addition,
it will also store the total number of through faults since last reset and total
I
2
t for each phase since last reset
(up to 256 records). The Through Fault Recorder log is stored in RAM and will be erased if power to the relay
is removed.
Target Storage
A total of 8 targets can be stored. This information includes the function(s) operated, the function(s) picked up,
input/output contact status, time stamp, phase and ground currents. The sequence of events log is stored in
RAM and will be erased if power to the relay is removed.
Calculations
Current and Voltage Values : Uses discrete Fourier Transform (DFT) algorithm on sampled voltage and current
signals to extract fundamental frequency phasors for M-3311A calculations.
Power Input Options
Nominal 110/120/230/240 V ac, 50/60 Hz, or nominal 110/125/220/250 V dc. UL rating, 85 V ac to 265 V ac and
from 80 V dc to 288 V dc. Burden 20 VA at 120 V ac/125 V dc. Withstands 300 V ac or 300 V dc for 1 second.
Nominal 24/48 V dc, operating range from 18 V dc to 56 V dc. Burden 20 VA at 24 V dc and 20 VA at 48 V dc.
Withstands 65 V dc for 1 second.
An optional redundant power supply is available for units that are purchased without the I/O Expansion Module.
For those units purchased with the I/O Expansion Module the unit includes two power supplies which are required.
Sensing Inputs
Up to Four Voltage Inputs: Rated nominal voltage of 60 Vac to 140 Vac, 50/60 Hz. Withstands 240 V continuous
voltage and 360 V for 10 seconds. Voltage input may be connected to phase voltage (L-G or L-L), or to a broken
delta VT. Voltage transformer burden less than 0.2 VA at 120 V.
Up to 15 Current Inputs: Rated current (
I
R
) of 5.0 A or 1.0 A (optional), 50/60 Hz. Withstands 3
I
R
continuous
current and 100
I
R
for 1 second. Current transformer burden is less than 0.5 VA at 5 A (5 A option), or 0.3 VA
at 1 A (1 A option).
Control/Status Inputs
The control/status inputs, INPUT1 through INPUT6, can be programmed to block any of the relay functions,
trigger the oscillographic recorder, select a setpoint group, or to operate one or more outputs. The control/status
inputs are designed to be connected to dry contacts and are internally wetted, with a 24 Vdc power supply. To
provide breaker status LED indication on the front panel, the INPUT1 status input contact must be connected
to the 52b breaker status contact. The minimum current value to initiate/pickup an input is >25 mA.
The optional Expanded I/O includes an additional 12 programmable control/status inputs.