GE Entelli-Switch 250 manual Sequence of Operation, ATS Type

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 provid- ed to bypass the "W" time delay if desired. After the (W) time delay, the CCE relay energizes the CE solenoid to close the transfer switch in to Source 2. The SE limit switch activates to de-energize the CCE relay.

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 stabiliza- tion before retransfer. A manual pushbutton BYPASS is provided to bypass the "T" time delay if desired. After the (T) time delay, the CCN relay energizes the CN solenoid to retransfer the switch to Source 1. The SN limit switch activates to de-energize the CCN relay.

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 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 stabiliza- tion before re-transfer. A manual pushbutton BYPASS is provided to bypass the "W" time delay if desired. After the (W) time delay, the CCNO relay energizes the CNO solenoid to open the transfer switch out of Source 1 position. The time delay to Source 2 timer (DW) begins its timing cycle. After the (DW) time delay, the CCE relay energizes. The switch then completes transfer to Source 2 by energizing the CE solenoid. The SE limit switch activates to de-energize the CCE relay.

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 stabi- lization before retransfer. A manual pushbutton BYPASS is provided to bypass the "T" time delay if desired. After the (T) time delay, the CCEO relay energizes the CEO solenoid to open the switch out of Source 2 position. The time delay to Source 1 timer (DT) begins its timing cycle. After the (DT) time delay, the CCN relay ener- gizes the CN solenoid to complete re-transfer of the switch to Source 1. The SN limit switch activates to de- energize the CCN relay.

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.

										Table 3
	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
Delay/ Open	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										Cooldown
					Returns

■ 24 Entelli-Switch 250 Operation and Maintenance Manual (71R-2000) GE Zenith Controls ■