12
Eaton PDI WaveStar TFA Static Transfer Switch Installation and Operation Manual P-164001113—Rev 01
Figure 7. Normal Mode MCSW and SCR Configuration
22..55..22
O
Oppeerraattiioonnaall M
Mooddeess:: N
Noorrm
maall aanndd B
Byyppaassss
In
Normal Mode
operation (Figure 7), the Monitor controls the transfer process:
•
The MCSWs for Source 1 and 2 are both closed, allowing a power path from either source, hence allowing
the load to be automatically transferred from one source to the other.
•
The Isolation MCSWs are closed to provide a power path for either source.
•
System logic opens or closes SCR 1 or SCR 2 to transfer the load rapidly from one source to the other.
•
Bypass 1 and 2 MCSWs are both open while the bypass is unused.
The Monitor logic continuously monitors the two power sources using its sensing algorithms and controls
transfers, using the POG or VSS algorithm, as specified by the user. The Monitor is itself continuously
monitored by the Simple Algorithm Switch (SAS), which provides a backup transfer process using a simpler
algorithm, if the Monitor fails.
In
Bypass Mode
operation (Figure 8), operators isolate logic and power components for maintenance by
changing the open/closed MCSW states. Keyed interlocks enforce correct coordination between MCSWs,
preventing cross-currents between sides. Bypass MCSWs are mechanically interlocked to both being closed at
the same time.
Summary of Contents for PDI WaveStar TFA STS 250-600A
Page 4: ......
Page 150: ...P 16400111301 P 164001113 01 ...
