Emerson Series 610 manual Load Transfer Procedures Screen, Load transfer procedures screen

Operation

3.2.8Load Transfer Procedures Screen

Go to the SCC Master Menu and move the highlighted cursor to LOAD TRANSFER PROCE- DURES. Note that this screen is displayed at the System Control Cabinet but is not required at the UPS modules. Press the Select pad and the Load Transfer Procedures screen is displayed.

The Load Transfer Procedures screen contains instructions to transfer the critical load between the UPS system and the bypass line. Comparisons of the UPS and bypass voltage, frequency and phase synchronization are displayed along with transfer status messages and an indication of circuit breaker overlap time. The metered parameter values on the Load Transfer Procedures screen are updated at half-second intervals.

Refer to 3.4.3 - Load Transfer Procedures for more details.

Figure 41 Load transfer procedures screen

HISTORY					MODULE1 -0-0 04/10/97/17/98 16:49:2111:21:59 FRAME36100
SELECT : MASTER MENU					- 00000			SITE TAG - 00000002
	VOLTAGE COMPARISON								Low Batt Warning				SYNCHRONIZATION
**** ACTIVE ALARMS ****				BattOutputDischargingOv-volts
UPS	-	A-B B-C C-A				B	FREQUENCY				-30			0		+30
		480	480	A480				C	DC	LOAD		HERTZ		TIME
OUTPUT VOLTS			480	380		380	38060.0 Hz
BYPASS	-	481		479		4	53041 60.0 Hz
OUTPUT AMPS				53041		41530
OUTPUT FREQUENCY				3				MANUAL				50.0
OUTPUTLOAD KVAVOLTS						380	380			349		UPS LEAD			=	2 Deg
	ON UPS					TRANSFER INSTRUCTIONS
OUTPUTBYPASS VOLTSAMPS				38041		41380	41380
OK TO TRANSFER				1.		Adjust the UPS voltage (1 - 5 volts) above the
OUTPUTTRANSFERVOLTSPROHIBIT				380		bypass voltage using the VOLTAGE ADJUST pot.
						3
OUPUT AMPS				2.		If the OK TO TRANSFER message is highlighted,
				410		410	410
						simultaneously press the BYPASS and CONTROL ENABLE
BATTERY AMPS				0		buttons.		0	-583
INPUT VOLTS						0
INPUT AMPS				3.		Verify that the transfer was					successful by checking the
				0		0		0				UP :		NEXT FRAME
				380		breaker status on the "MONITOR/MIMIC" screen.
OUPUT VOLTS						380	380
OUTPUT AMPS				4.		Press the ALARM RESET button to clear alarms which
				410		410	410					DOWN :		PREVIOUS FRAME
LOAD KVA						are no longer active				270
											SELECT : EXIT

Item 1 - Voltage Comparisons: This chart shows the UPS and bypass voltage and frequency com- parisons between each of the three phases. If the UPS and bypass voltages are not within specified tolerances, a manual transfer is not permitted and TRANSFER PROHIBIT is highlighted.

The Voltage Adjust knob (push-to-turn), located on the SCC Operator Control Panel (Figure 10), is used to adjust the UPS output voltage (1 - 5 volts) above the bypass voltage. When the UPS and bypass voltages are within the specific tolerance, a manual transfer is possible and OK TO TRANS- FER is highlighted.

! CAUTION

The UPS output voltage responds very slowly to inputs from the Voltage Adjust knob. Make small adjustments and wait several seconds each time for voltage to stabilize before continuing.

Item 2 - Synchronization: This display shows the phase synchronization between the UPS output and bypass power. If the phase displacement is outside of the tolerance, a manual transfer is not per- mitted and TRANSFER PROHIBIT is highlighted.

During normal operation, the synchronization display should read UPS LEAD from zero to 4 degrees.

Item 3 - Status Messages: Three messages are constantly displayed here. Only the active message is highlighted. If TRANSFER PROHIBIT is highlighted, manual transfers/retransfers cannot be performed and automatic retransfers will not be initiated.

Item 4 - Manual Transfer Instructions: These instructions assist the operator in transferring the critical load between the UPS system and the bypass line.

If the load is on the bypass line, step 2 on the screen will instruct you to press the UPS and Control Enable buttons to retransfer the load from the bypass line to the UPS system.

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