Effective 10/2004
Page 26
I.L. 70C1036H05
main conductors at the top of the circuit breaker. This is
the factory wired setup. A factory option does exist to
enable bottom end of circuit breaker sensing of voltage.
NOTE:
Frequency is sensed on phase A voltage input.The
Frequency Trip, Voltage Trip or Alarm function will not be
active if this voltage falls below 84 volts phase to phase.
4.2.2.2 Voltage, Frequency Trip
Voltage and Frequency Protection Trip functions, if en-
abled, are active whenever the circuit breaker is
closed.These trip functions are made inactive after a trip or
when the circuit breaker opens. The function will be
rearmed when the circuit breaker is reclosed. Observe the
cause of trip message after a trip event then reset the
Digitrip by depressing the Reset pushbutton. At this time
observe the real time data of the parameter that initiated
the trip to see if it is still beyond the specified limit.
Voltage and frequency data in the Meter menu is real time
data independent of whether the circuit breaker is open or
closed. Enter the EventLog menu and observe the event
that initiated the trip. When the parameter returns to within
its limits, reclose the circuit breaker if desired.
4.2.2.3 Voltage, Frequency Alarms
These alarms can be enabled by the user by entering the
Program Settings and then the Alarms submenu.Alarms
are real time and are active when the circuit breaker is in
either the open, closed or trip state. The alarm LED will
light to indicate an alarm condition.
NOTE:
If an UnderFrequency or OverFrequency Trip or
Alarm is enabled, the following restriction applies: Trip
units used on 50 Hz systems have valid frequency sensing
range of 43 to 59 Hz. Trip units used on 60 Hz systems
have a valid frequency sensing range of 51 to 70 Hz. All trip
units leave the factory set for 60 Hz. For frequencies
outside the applicable range, the unit will display the alarm
message “FREQ OUT OF BOUNDS”.
This alarm message also can occur if the system fre-
quency setpoint does not match the nominal power
system frequency. If this message is encountered, check
or change the frequency setting in the System menu. The
FREQ display screen in the Meter sub-menu will display
dashes, “-----“, instead of a numerical frequency.
The circuit breaker will not initiate a frequency related trip
when programmed to provide frequency tripping for frequen-
cies out of bounds. However, the alarm relay Relay A, if
programmed for frequency alarming, will operate during an
out of bounds condition as well as within the valid fre-
quency range of operation.
4.2.1.10.2 Phase Loss - (Current Based)
The phase loss trip function can be selected in the Pro-
gram Settings - Program Curve Menu
(See Appendix D-
12).
It is set to OFF initially as a factory default. A Time
Delay of 1 to 30 seconds can be selected. If there exists a
75% difference between the Max phase and Min phase
currents and if maintained for the selected time delay, the
breaker will trip with a PHASE LOSS TRIP message and
red Trip LED illuminated in the right corner of the Digitrip
front panel.
This function does require auxiliary power
to the Digitrip unit.
To avoid unnecessary operation of
this function the circuit breaker must be carrying 55% of
the
I
r rating on at least one phase before it will trip via
Phase Loss.
4.2.2 Voltage - Frequency, Reverse Power
Refer to Table 1.1d for a tabulation of functions available
versus the catalog number. Voltage and Frequency and
Reverse Power tripping and/or Alarming can be set by
entering the VOLTAGE menu under the Program Setting
main menu. Please refer to Appendix D-23 for the trip
settings available and Appendix D-16 for the Alarm settings
available. The Alarms can be mapped to Relay A and the
Trips to Relay B and Relay C for desired relay contact
action.
The Voltage function (Frequency and Reverse Power
included) has a master switch “voltage setting” [enabled/
disabled] that can toggle all voltage related trip and alarm
settings. The individual selections can, in addition, be
enabled or disabled as desired.
NOTE:
When programming the Voltage or Frequency
setting for Trip or Alarm, there exists a setting
interdependancy feature that prevents the user from
making an “over-lapping” under and over value combination.
When this condition is encountered, change the value or
disable the “opposite” setting temporarily to achieve the
desired setting.
4.2.2.1 Voltage, Frequency Protection
These functions, unlike the LSIG Current protection
functions, do require a reliable source of auxiliary
power available on circuit breaker secondary con-
tacts A-14, A-15.
If the circuit breaker is equiped with the
24-48VDC Power/Relay Module, the (+) voltage input is
terminal A-14.Refer to the breaker information label for
proper trip unit power voltage and see also Section 1.6 and
Appendix C.
The Voltage is sensed on all three phases. Any phase to
phase voltage exceeding the specified setting will activate
the protection function. The voltage sensing points are the
