System Setup and Setpoints – 4
4–63
MANUAL TRANSFER SETTINGS/HOT
PARALLEL TRANSFER TAB
Path:
System/Setup/Setpoints/Manual Transfer
Settings/Hot Parallel Transfer
The Hot Parallel Transfer tab (Figure 4-63) displays
the settings for the Hot Parallel Transfer. The top
right corner of the display includes a command
button that will disable or enable the Manual Hot
Parallel Transfer. Whenever the Hot Parallel Transfer
is enabled the Manual Fast, Delayed In-phase and
Residual Transfers are disabled. Only when the Hot
Parallel Transfer is disabled can the Manual Fast,
Delayed In-phase and Residual Transfers be
enabled.
The Hot Parallel Transfer is typically used to transfer
the motor load back to the original source after an
Automatic Transfer has been completed and the
conditions that caused it to occur have been
resolved. This transfer operates differently than all
the other transfers, in that it closes the breaker to
the new source first and then opens the breaker to
the old source. This allows for a bumpless transfer
since the motor bus is never disconnected from a
source. The Hot Parallel transfer is only performed
when the bus and new source conditions are stable.
Manual Hot Parallel Transfer/Delta Phase Angle
Limit
The Delta Phase Angle Limit
can be set from 0.0 to
90.0 degrees. The delta angle is the angle between
the voltages of the motor bus and the new source.
This setting cannot be disabled. The phase angle is
always one of the parameters used to determine if a
Hot Parallel Transfer can be executed.
Manual Hot Parallel Transfer/Delta Voltage
Limit
The Delta Voltage Limit
can be set from 0 to 60
volts. The delta voltage is the voltage difference
between the motor bus and the new source. This
setting can be disabled and if it is disabled, then
this parameter is not used as a condition to execute
a Hot Parallel transfer.
Manual Hot Parallel Transfer/Delta Frequency
Limit
The Delta Frequency Limit
can be set from 0.02 to
0.5 hertz. The delta frequency is the frequency
difference between the motor bus and the new
source. This setting can be disabled and if it is
disabled then this parameter is not used as a
condition to execute a Hot Parallel Transfer.
Manual Hot Parallel Transfer/Time Window
The Time Window
can be set from 1 to 50 cycles.
The Time Window defines the window of opportunity
for a Hot Parallel Transfer. The Time Window starts
when the transfer is initiated and ends at the selected
time limit. If a Hot Parallel Transfer has not been
completed by the end of this Time Window, then the
Hot Parallel Transfer is disabled and will no longer
be attempted and an Incomplete Transfer alarm will
be set.
Manual Hot Parallel Transfer/Tripping
Command Time Delay
The Tripping Command Time Delay can be set from
0 to 30 cycles. The Tripping Command Time Delay
is the time from when the new source breaker
closes until the old source breaker is tripped. This
time defines how long the two sources are paralleled.
This time setting should be set as short as possible
to limit the amount of time the motor bus would be
exposed to double fault currents.
Manual Hot Parallel Transfer/Blocking Inputs
Selection
The Blocking Inputs Selection
button opens the
Blocking Inputs Selection dialog screen (Figure
4-64). Any Input or the Fuse Loss (FL) function can
be selected to block a Hot Parallel Transfer.
Manual Hot Parallel Transfer/Save/Cancel
The Save selection saves the Manual Hot Parallel
Transfer settings either to an open file or to the
target MBTS. Cancel, returns the user to the
previous open screen.
The conditions that are necessary to execute a Hot
Parallel Transfer are:
•
No lockout/blocking conditions exist.
•
The phase angle between the motor bus
and the new source is within limit setting.
•
The delta voltage between the motor bus
and the new source is within limit setting.
•
The delta frequency between the motor
bus and the new source is within limit
setting.
•
A transfer must be completed within the
Hot Parallel Transfer time window of 1 to
50 cycles.
Summary of Contents for M-4272
Page 1: ...Instruction Book Book 1 of 2 M 4272 Motor Bus Transfer System ...
Page 45: ...xviii M 4272 Instruction Book This Page Left Intentionally Blank ...
Page 200: ...System Setup and Setpoints 4 4 89 Figure 4 93 ISSLogic Function Dialog Screen ...
Page 207: ...M 4272 Instruction Book 4 96 This Page Left Intentionally Blank ...
Page 214: ...Declaration of Conformity Appendix I I 1 IAppendix I Declaration of Conformity ...
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