Operation
54
3.2.8 Load 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

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 match the UPS output voltage to the bypass voltage. When the UPS and bypass voltages

match within the specific tolerance, a manual transfer is possible and OK TO TRANSFER is high-

lighted.

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.

!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.

OUTPUTVOLTS
OUTPUTAMPS
OUTPUTFREQUENCY
LOADKVA
BYPASSVOLTS
A
380
530
380
DC
B
380
530
380
TIMELOAD
349
C
380
530
380
HERTZ
50.0
NEXTFRAME
PREVIOUSFRAME
EXIT
UP :
DOWN :
SELECT :
HISTORY STATUS MODULE-0 04/10/97 16:49:21 FRAM E36
ORDER- 000000 SITE ID - 00000 SITETAG - 0000000
****ACTIVE ALARMS **** Output Ov-volts
OUTPUTVOLTS
OUTPUTAMPS
OUTPUTFREQUENCY
OUTPUTVOLTS
OUTPUTAMPS
BATTERYVOLTS
OUTPUTVOLTS
OUPUTAMPS
BATTERYAMPS
INPUTVOLTS
INPUTAMPS
OUPUTVOLTS
OUTPUTAMPS
LOADKVA
A
380
410
380
410
380
410
0
0
380
410
DC
390
-583
B
380
410
380
410
380
410
0
0
380
410
TIME
0:01
LOAD
270
C
380
410
380
410
380
410
0
0
380
410
HERTZ
50.0
NEXTFRAME
PREVIOUSFRAME
EXIT
UP :
DOWN :
SELECT :
HISTORY STATUS MODULE-0 01/17/98 11:21:59 FRAME 100
ORDER- 000000 SITE ID - 00000 SITETAG - 0000000
****ACTIVE ALARMS **** Batt Dischar ging LowBatt Warning
TRANSFERPROHIBIT
UPS LEAD = 2Deg
UPS -
BYPASS -
480480
480481
B-CA-B
VOLTAGECOMPARISON
SELECT : MASTERMENU
OK TO TRANSFER
+30
ONUPS
60.0Hz
479
C-A FREQUENCY
MANUAL
TRANSFERINSTRUCTIONS
1. Adjustthe UPS voltage until it equals the
bypassvoltage wit h the VOLTAGEADJUST pot.
2. Ifthe OK TO TRANSFER message is highlighted,
simultaneouslypress the BYPASS and CONTROL ENABLE
buttons.
3. Verifythatthe transfer was successful by checking the
breakerstatus on the "MONITOR/MIMIC" screen.
4. Pressthe ALARM RESET button to clear alarms which
areno longer act ive
SYNCHRONIZATION
60.0Hz
0-30
480
12
4
3