Basler Electric BE1-11t - Manual (Page 15)

9424200995 Rev H 3
A backup capacitor and additional battery backup are provided for the clock. During a loss of operating
power, the backup capacitor maintains timekeeping for up to 24 hours depending on conditions. As the
capacitor nears depletion, the backup battery takes over and maintains timekeeping. The backup battery
has a life expectancy of greater than five years depending on conditions.
IRIG
A standard unmodulated IRIG-B input receives time synchronization signals from a master clock.
Automatic daylight saving time compensation can be enabled and set for floating or fixed dates.
NTP (Network Time Protocol)
NTP synchronizes the real-time clock to network time servers through the Ethernet port. BESTCOMSPlus
is used to establish the priority of time reference sources available to the BE1-11t, IRIG-B, NTP, DNP,
and RTC (real-time clock). The NTP address is set using BESTCOMSPlus.
Communications
Three independent communication ports provide access to all BE1-11t functions. A USB (universal serial
bus) port is located on the front panel, a two-wire RS-485 port is located on the rear panel, and an
optional Ethernet port is also located on the rear panel. The RS-485 and Ethernet ports are electrically
isolated.
Modbus ™ and DNP3 protocols are optionally available for the RS-485 or Ethernet communication port.
The IEC 61850 protocol is optionally available for the Ethernet port. Separate instruction manuals cover
each available protocol. Consult the product bulletin or Basler Electric for availability of these options and
instruction manuals. Modbus sessions can be operated simultaneously over the Ethernet and RS-485
ports.
System Parameters
Three-phase currents and voltages are digitally sampled and the fundamental is extracted using a
Discrete Fourier Transform (DFT) algorithm.
The voltage sensing circuits can be configured for single-phase, three-phase-three-wire, or four-wire
voltage transformer circuits. Voltage sensing circuitry provides voltage protection, frequency protection,
polarizing, and watt/var metering. Neutral-shift, positive-sequence, and negative-sequence voltage
magnitudes are derived from the three-phase voltages. Digital sampling of the measured frequency
provides high accuracy at off-nominal values.
An auxiliary voltage sensing input (Vx) provides protection capabilities for over/undervoltage monitoring of
the fundamental and third harmonic voltage of the VT source connected to the Vx input. This capability is
useful for ground fault protection.
Each current sensing circuit has low burden and is isolated. Neutral, positive-sequence, and negative-
sequence current magnitudes are derived from the three-phase currents. An independent ground current
input is available for direct measurement of the current in a transformer neutral, tertiary winding or flux
balancing current transformer.
Programmable Inputs and Outputs
Programmable contact inputs and outputs are described in the following paragraphs.
Programmable Inputs
Seven programmable contact sensing inputs with programmable signal conditioning provide a binary logic
interface to the protection and control system. Each input function and label is programmable using
BESTlogicPlus. A user-meaningful label can be assigned to each input and to each state (energized and
de-energized) for use in reporting functions. Board mounted jumpers support dual voltage ratings.
Programmable Outputs
Eight programmable general-purpose contact outputs provide a binary logic interface to the protection
and control system. One programmable, failsafe contact output serves as an alarm output. Each output
BE1-11t Introduction