MYPV ClearSky Plus, User Manual, Page: 35 / 106

Protection Relay Settings 35
7. MV Breaker controller CLOSEs MV Breaker (52)
8. SEL-751 verifies MV Breaker CLOSE via AUX contact (52a)
9. When the RVC Controller is signaled. By the SEL-751 that the MV Breaker has
CLOSEd, the RVC Controller delays 2.5s before commanding the LV Relay
Contactor to OPEN
10. The RVC Controller indicates READY TO EXPORT mode when the LV Relay
Contactor AUX OPEN position is verified
TRIP SEQUENCE
1. TRIP command to SEL-751 (RVC, Local, Software, or SCADA)
2. SEL-735 sends TRIP command to MV Breaker controller
3. MV Breaker controller TRIPs MV Breaker (52)
4. SEL-751 verifies MV Breaker TRIP via AUX contact (52a)
5. SEL-751 inhibits RVC Controller operation with NOT READY state
RELAY & RVC OPERATION BEHAVIORS
If the SEL-751 sends a CLOSE signal to the RVC Controller (starting the switching
sequence), but the SEL-751 does not receive a MV CLOSE command from the
RVC Controller within 30s the CLOSE attempt will be abandoned. Normally, the
RVC Controller would request a MV CLOSE at 15s following the SEL-751’s initial
CLOSE signal.
The RVC Controller will initiate a TRIP command to the SEL-751 on the following
conditions:
Power Supply failure
UPS Battery Backup failure
Loss of Control Power
Loss of LV Relay Contactor OPEN/CLOSE position
Loss of MV Breaker 52a TRIP/CLOSE position
CLOSE operation not completing within a reasonable time (30s)
In all cases, the SEL-751’s protection elements override the RVC Controller
switching sequences.