Installation
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3.3.3 OPEN BOTH BREAKERS
This application may be required if the size of the load requires both the generator and mains supplies
to be in parallel.
In this application, if the mains supply fails, the generator supply is incapable of supplying the load so
both breakers must be opened.
It is recommended that the DSEP100 is used to open the mains breaker AND generator or common
bus breaker directly, giving signal to the opening or tripping coil. This ensures that the decoupling
operation occurs as quickly as possible after the signal to open is given by the DSEP100.
In addition to this, it is recommended that the DSEP100 signal is also given to any other device that
has control over the generator or common bus breaker. For example this could be a DSE8660 type
controller.
Where connected to a DSE module with control over the generator or common bus breaker, this
signal is fed into a digital input configured to “Electrical Trip” and to another digital input configured to
“Auxiliary Mains Failure”. This ensures that this controller is informed about the mains decoupling
operation and can take action itself to open the mains breaker AND generator or common bus
breaker.
Additionally, the DSE module must have “Immediate Mains Dropout” enabled. This configures the
controller to open the mains breaker as soon as the input is received from the DSEP100 device.
Failure to do this may result in “Fail To Close” alarms caused by the breakers opening not under
control of the DSEP100.
