Test Menu - S&C MIcro-AT Installation, Programming, And Operation Manual

Field Adjustment and Programming

Test Menu

28 S&C Instruction Sheet 515-600
If the loss-of-left source time is to be set to some other value, press the
CHANGE key. If the display prompts you to reenter the access-code number,
do so. The display will now look like this:
Enter the desired loss-of-left source time. If, for example, 10.5 seconds is the
desired value, the "1," "0," ".," and "5" keys would be pressed, followed by the
ENTER key. The display will change to:
The other items of the Time menu can be changed in the same manner.
Considerations for time delays is as follows:
• The loss-of-left-source and loss-of-right-source time delays should be set for val-
ues sufficient to establish that the loss of source is not transient (thus preventing
unnecessary transfers). Care should be exercised to ensure these settings coordinate
properly with those of the upstream protection devices.
• The return-of-source time delay should be set for a value sufficient to establish that
return of preferred-source is not temporary.
• The lockout-reset time delay should be set for a value greater than the longest
clearing time of all feeder fuses.
• The transition dwell time delay should be set for a value greater than the longest
time required for motor residual voltage (the voltage appearing at the terminals of
a connected motor when the source is interrupted) to drop to 25% or less of rated
voltage.
STEP 6. Perform the loss-of-source testing and overcurrent-lockout testing outlined in
the "Operational Testing" section on page 30.
The Test menu provides a means for checking the functioning of the source-transfer
control. Items listed under this menu include the following:
• Test lamps
• Test display
• Test keypad
• Enable test keys—The means for enabling loss-of-source testing and overcurrent-
lockout testing, as described under the "Operational Testing" section on pages 30 and 31
TIME: LOSS OF LEFT SOURCE
2 . 00 SECONDS
TIME: LOSS OF LEFT SOURCE
1 0 . 5 SECONDS
– – – –
CHANGE