Auxiliary Relay (Optional); Remote Indicator (Optional); Manual Test And Reset - Cybertronix Sentinel EFI-MFZ-50 User Manual

Sentinel™ EFI-MFZ-50 User's Manual
The indicating unit is powered from the mains supply and also uses the presence of
healthy mains to reset the unit. When healthy mains is first applied or when it returns after
a cleared fault condition, the unit will first require up to 5 minutes to charge the onboard
supply capacitors before it is functional. The presence of mains voltage will also reset the
unit if it is in a tripped state.
The indicating unit continuously monitors the output signal from the current sensor. The
current sensor transmits a voltage which is proportional to the measured current. For
primary currents in excess of 50A the current sensor saturates and a limiting circuit inside
the indicating unit clamps the output voltage to below 10V even for high fault currents.
When an imbalance is detected, onboard circuitry analyses the fault current. The
magnitude and duration of the half cycles of fault current are measured. Current spikes
and glitches are ignored. As soon as valid fault current has been detected, the Sentinel
triggers and enters a tripped state. A trip will flip the Flag into a tripped positon.

5.2.1 AUXILIARY RELAY (OPTIONAL)

An on-board auxiliary relay provides a potential-free, normally-open contact for additional
signaling. A 2-way screw terminal is provided on-board to which the user can connect a
signaling cable. The auxiliary relay is operated from the same circuitry controlling the Flag.
Thus when healthy mains is first applied or when it returns after a cleared fault condition,
the unit may require up to 5 minutes to charge the onboard supply capacitors after which it
then resets. A reset will latch the relay into the reset position (open). A tripped state will
latch the relay into a tripped position (closed).

5.2.2 REMOTE INDICATOR (OPTIONAL)

An optional remote indicator can be ordered pre-installed or ordered separately. A 2-way
screw terminal is provided on-board for connection of the remote indicator. It provides
flashing LED indication at some distance from the main indicating unit. During a tripped
state the unit will flash at a rate of about 1Hz. The remote indicator is weather-proof and is
housed inside a stainless steel bolt which also makes it vandal-proof. The on-board
circuitry which drives the remote indicator requires at least 5 minutes of mains charging
when first connected to the mains supply.

5.2.3 MANUAL TEST AND RESET

A pushbutton located on the front panel allows the unit to be manually tested or reset. The
button must be depressed for at least 3 seconds before it will activate. This is to avoid
accidental operation. The EFI can only be manually tested if the unit has been charged by
the mains supply for up to 5 minutes. The manual test feature can both trip and reset the
EFI.
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