GE Industrial Solutions ZBTSD Series - Manual (Page 22)

20 71R -4000B ■ ZBTS / ZBTSD Operation & Maintenance Manual
Sequence of Operation
Standard Transition
Source 1 Power Failure:
When Source 1 voltage or frequency has fallen below the
preset “Fail” values, the controller initiates the Time Delay
Source 2 Start Timer (Engine Start Timer “P”) cycle. Upon
completion of the (P) time delay, an Engine start Signal
is sent to Source 2. When Source 2 voltage and frequency
reach the preset “Restore” Values, the time delay to Source 2
Timer (W) begins its timing cycle to ensure voltage and
frequency stabilization before transfer. A manual push-
button BYPASS is provided to bypass the “W” time delay
if desired. After the (W) time delay, the MX controller
initiates a transfer signal through the SCR-E to operate the
main transfer operator. The load is now transferred to
Source 2 line. The transfer switch is mechanically locked.
SN limit switch awaits the next operation to Source 1.
Restoration of Source 1 Power:
When Source 1 power reach the preset “Restore” values,
the controller initiates re-transfer to Source 1 sequence.
The delay to Source 1 Timer (T) begins its timing cycle
to ensure voltage and frequency stabilization before
retransfer. A manual pushbutton BYPASS is provided to
bypass the “T” time delay if desired. After the (T) time
delay, the MX controller initiates a transfer signal through
the SCR-N to operate the main transfer operator. The
load is now transferred to Source 1 line. The transfer
switch is mechanically locked. SE limit switch awaits the
next operation to Source 2.
Immediately after re-transfer, the S2 Stop Delay Timer
(Delay to Engine Stop “U”) begins its cycle to allow
Source 2 Engine to run unloaded. A manual pushbutton
BYPASS is provided to bypass the “U” time delay if desired.
Upon completion of the (U) timing cycle, the controller
sends an Engine stop signal.
Delayed Transition
Source 1 Power Failure:
When Source 1 voltage or frequency has fallen below the
preset “Fail” values, the controller initiates the Time Delay
Source 2 Start (Engine Start Timer “P”) cycle. Upon
completion of the (P) time delay, an Engine start Signal
is sent to Source 2. When Source 2 voltage and frequency
reach the preset “Restore” values, the time delay to open
Source 1 timer (W) begins its timing cycle to ensure
voltage and frequency stabilization before re-transfer.
A manual pushbutton BYPASS is provided to bypass the
“W” time delay if desired. After the (W) time delay, the
MX controller initiates a transfer signal through the
SCR-NO to operate the main transfer operator. The load
is now transferred to the Open position. The time delay to
Source 2 timer (DW) begins its timing cycle. After the (DW)
time delay, the MX controller initiates a transfer signal
through the SCR-E to operate the main transfer operator.
The load is now transferred to Source 2 line. The transfer
switch is mechanically locked. SN limit switch awaits the
next operation to Source 1.
Restoration of Source 1 Power:
When Source 1 power reach the preset “Restore” values,
the controller initiates re-transfer to Source 1 sequence.
The delay to open Source 2 Timer (T) begins its timing
cycle to ensure voltage and frequency stabilization before
retransfer. A manual pushbutton BYPASS is provided to
bypass the “T” time delay if desired. After the (T) time
delay, the MX controller initiates a transfer signal through
the SCR-EO to operate the main transfer operator. The
load is now transferred to the Open position. The time delay
to Source 1 timer (DT) begins its timing cycle. After the
(DT) time delay, the MX controller initiates a transfer
signal through the SCR-N to operate the main transfer
operator. The load is now transferred to Source 1 line.
The transfer switch is mechanically locked. SE limit
switch awaits the next operation to Source 2.
Immediately after re-transfer, the S2 Stop Delay Timer
(Delay to Engine Stop “U”) begins its cycle to allow
Source 2 Engine to run unloaded. A manual pushbutton
BYPASS is provided to bypass the “U” time delay if desired.
Upon completion of the (U) timing cycle, the controller
sends an Engine stop signal.
Timer Designations as they appear in the SET menu
ATS Type P W DW T DT U
Standard Time Delay Time Delay Time Delay S2 Stop
Transition S2 Start S2 Stable S1 Stable Delay
Delayed Time Delay Time Delay ATS Open Time Delay ATS Open S2 Stop
Transition S2 Start S2 Stable Time to S2 S1 Stable Time to S1 Delay
Source 1 Transfer to Source 2
Source 1
Transfer to Source 1 Engine
Fails
Returns
Cooldown
Table 4