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Eaton Static Transfer Switch 2000A 3-Pole Installation and Operation Manual 164001127—Rev 01
Figure 6. Normal Mode MCCB/MCSW and SCR Configuration
In Normal Mode, breakers
(MCCBs and MCSWs) are fixed
in the open/closed configuration
shown here.
In Normal Mode,
-Source (Input) 1 and 2 MCCBs
are both closed, allowing either
source to power the load.
-Bypass breakers are both open.
-The Isolation (Iso) MCSWs are
closed to allow a power path from
either source.
One-line Diagrams
are from the Home
screen.
In the illustration to the left,
-SCRs determine the
active power path under
control of system logic. In
this illustration,
-SCR 1 is closed (active
path).
-SCR 2 is open (inactive
standby path).
- Source (Input 2) is powering the load.
- SCR 2 is closed, SCR 1 open.
- Isolation switches are closed to allow a
power path from either source.
Note: Only (1) Isolation Switch is required;
(2) Isolation Switches provide redundancy.
In Normal Mode operation (
), the Monitor controls the transfer process:
•
The MCCBs for Source 1 and 2 are both closed, allowing a power path from either source, henceallowing
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 MCCBs 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.
Summary of Contents for STS 2000A
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