Sequence Of Operation; Standard Transition; Delayed Transition - GE 70R-1000D Operation And 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 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-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 1sequence.
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 opera-
tor. 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 pushbut-
ton 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
Timer Designations as they appear in the SET menu
ATS Type P
Standard Time Delay
S2 Start
Delay Time Delay
S2 Start
Source 1
Fails
GE Zenith Controls
W DW
Time Delay
S2 Stable
Time Delay ATS Open
S2 Stable Time to S2
Transfer to Source 2
ZTG/ZTGD Operation and Maintenance Manual (70
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 throught 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 pushbut-
ton 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.
T
Time Delay
S1 Stable
Time Delay ATS Open
S1 Stable Time to S1
Transfer to Source 1
Source 1
Returns
R -1000D)
Table 3
DT U
S2 Stop
Delay
S2 Stop
Delay
Engine
Cooldown
21