Rockwell Automation 1608M MegaDySC User Manual, 800 - 2400 A - Manual (Page 15)

Rockwell Automation Publication 1608M-UM002A-EN-P - September 2013 15
Communications Chapter 3
TB1 Contacts Functionality
ALARM Contacts
The NC contact will be closed during normal operating conditions. The NC
contact will open if an alarm condition occurs that inhibits sag correction. It will
also close when the DySC system is powered down (when the touchscreen
display is off ).
If and when an alarm condition clears (for example, a Static Switch Overload no
longer exists) the relay will revert to its pre-fault position.
Alarms that will energize the Alarm Relay K1 coil are all those listed in Table 6 on
page 36 with a severity of “Auto-Resetting” or “Call Service.”
OUTPUT OK Contacts
The NC contact will be open during normal output (load) voltage conditions.
The NC contact will close if the output rms voltage falls below 87% of rated for
more than 3 cycles. It will also close when the DySC system is powered down.
SAG EVENT Contacts
The NC contact will be closed during normal input (line) voltage conditions.
The NC contact will open during a detected voltage sag event. It will also close
when the DySC system is powered down.
During a voltage sag, the relay coil will be energized for a minimum of 1 cycle,
(16ms in 60 Hz application, 20ms in 50 Hz application), and for the duration of
the detected event. The maximum relay close time is 25 ms, so some single-cycle
events may not operate this relay contact. The maximum relay release time is 25
ms; the expected minimum pulse width is approximately 15-25 ms.
CBB STATUS Contacts
“Normal” position for the CBB Bypass Breaker is defined as the breaker being
OFF, or Open. The Normally-Open (NO) auxiliary contacts are open when the
Breaker is open.
NOTE :When the CBB breaker is closed, the MegaDySC cannot provide
protection against sags.
Example: Normal mode: CBB will be Open; therefore CBB-NO = open, CBB-
NC = closed. If CBB is closed, these states will be reversed.