Operation
31
6.4.5 BREAKER SCHEME B
Breaker Scheme B is intended only for use with certain designs of transfer switch. If you are using contactors, you
MUST select Breaker Scheme A.
6.4.5.1 CHECK SYNCHRONISING IS DISABLED
6.4.5.1.1
TRANSFERRING TO S2
To open S1 breaker the
Open S1
output energises, it then de-energises when the
S1 Closed Auxiliary
indicates it
has successfully opened, or after 1s whichever occurs first.
When ‘S1 Closed Auxiliary’ indicates the S1 breaker has opened, the
transfer timer
begins.
When the
transfer timer
expires, the module attempts to close S2 breaker by energising the
Open S1
and
Close S2
outputs simultaneously, it then de-energises these outputs when the
S2 Closed Auxiliary
input indicates it has
successfully closed, or after 1s whichever occurs first.
6.4.5.1.2
TRANSFERRING TO S1
To open S2 breaker the
Open S2
output energises, it then de-energises when the
S2 Closed Auxiliary
indicates it
has successfully opened, or after 1s whichever occurs first.
When the ‘S2 Closed Auxiliary’ indicates the generator breaker has opened, the
transfer timer
begins.
When the
transfer timer
expires, the module attempts to close S1 breaker by energising the
Open S2
and
Close S1
outputs simultaneously, it then de-energises these outputs when the
S1 Closed Auxiliary
input indicates it has
successfully closed, or after 1s whichever occurs first
6.4.5.1.3
LOAD SHED INPUT
When the
Load Shed
input is activated while the generator is closed the
Open S2
output energises, it then de-
energises when the
S2 Closed Auxiliary
input indicates that it has successfully opened, or after 1s whichever occurs
first.
When the
Load Shed
input is activated while the mains is closed the
Open S1
output energises, it then de-
energises when the
S1 Closed Auxiliary
input indicates that it has successfully opened, or after 1s whichever occurs
first.
When the
Load shed
input is de-energised the load is returned to the supply that was disconnected, providing that
supply is healthy.
6.4.5.1.4
TIMING DIAGRAM
Open S1
Close S2
Close S1
Open S2
Non-Sync Transfer Time
Non-Sync Transfer Time
S2 has closed
S1 has closed
S1 has opened
S2 has opened