Glossary
76
Glossary
A
ACCESS system
A power monitoring and control system by
Siemens. The SB Energy-Comm trip unit is one of several
ACCESS system field devices that can communicate with a per-
sonal computer or other supervisory device.
ACCESS baud rate
See Baud Rate.
ACCESS port
The RS-485 port on the trip unit that allows it to
communicate on the ACCESS system. The physical connection
is made on the terminal strip on the left side of the breaker.
acceptance test
A preliminary check performed when the
device is first received to ensure that it has not been damaged in
shipment or retrieval from storage. The SB Energy-Comm trip unit
provides a trip test to determine that the trip unit will send the
proper trip signal to the breaker, and that the breaker will trip
when signalled.
accessory
An optional device that can add functionality to the
trip unit. All accessories for the SB Energy-Comm unit are exter-
nal to the trip unit.
address
The programmable, unique identifier of the device on
the ACCESS system. It is used by the supervisory device to iden-
tify the device when communicating.
alarm
A signal from the trip unit that can trigger an alert, such
as a buzzer or flashing light, that an event has taken place.
alarm setpoint
A programmable value, such as current or volt-
age, which if exceeded, the trip unit will send an alarm signal.
American Wire Gauge (AWG)
A standard system for desig-
nating wire diameter. Primarily used in the United States.
amps demand
See
Current Demand
.
ANSI
American National Standards Institute.
B
baud rate
The rate of data transfer. The baud rate can be set
separately for the ACCESS communications RS-485 port and the
front RS-232 port.
breaker
See
Circuit Breaker
.
breaker frame size
The physical size of the breaker based on
its maximum current rating. The SB breaker has five frame sizes.
Each breaker frame size has a range of available breaker current
ratings.
breaker rating
The current rating of the breaker. SB breaker
ratings vary from 400 A to 5000 A. It is set by the rating plug.
breaker serial number (S/N)
A five-digit number entered in
the trip unit that uniquely identifies its associated breaker. Valid
numbers range from 00000 to 99999.
C
catalog number
See
Order Number
.
circuit breaker
The circuit interrupting device (Sentron Sys-
tems Breaker) that the SB Energy-Comm trip unit is mounted in.
Communications menu
The menu selection available from the
Main menu which allows the configuration of communications
with a supervisory device.
communications
The interchange of data and information
between the SB Energy-Comm trip unit and a supervisory device.
The trip unit has a serial port for communications with a PC plus a
RS-485 port for communications between a network of ACCESS
field devices and a supervisory device.
continuous current
See
Long Time
.
counters
The SB Energy-Comm trip unit tracks the number of
breaker operations. There are three types of counters: mechani-
cal, interruption, and fault.
crest factor
The ratio between the peak and RMS current,
measured per phase.
CT
current transformer. A device which generates a current pro-
portional to that in the measured line.
current balance
See
Phase Balance
.
current demand
The measurement and summation of metered
current over a specified time.
current rating
See
Breaker Rating
.
current unbalance alarm
An alarm activated when the phase
current for any one phase exceeds the average current by a set
value. The breaker may also be programmed to trip at this, or
another value. This feature is available from the Protective Relays
menu.
D
delay
The amount of time that the trip unit waits before tripping
or alarming after a monitored value exceeds the alarm or trip set-
ting.
