Eaton EFX48 e-Fuse Series, Installation And Operation Manual

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EFX48 e-Fuse System Operation
Copyright © 2019 Eaton Corporation. All Rights Reserved.
IPN March 2019
95
Float dwell time is the time the system has to have been continuously in float state before the
mid-point monitoring process is activated.
Midpoint delay is a further delay after float dwell time that the alarm must have been active for,
before issuing the alarm.
Voltage threshold is a percentage that defines the error above which a failure is detected.
Example - if the total voltage is 54V then the mid-point should be 27V and if the threshold is
10% then below 0.9 x 27V or above 1.1 x 27V a string Midpoint alarm will be raised if it has
been enabled in the configuration.
The midpoint monitoring process is only active if the battery remains in the float state.
The Midpoint alarm is cancelled by disabling the alarm in the configuration or by the midpoint
voltage becoming within limits for greater than the midpoint delay.
Note that the midpoint monitoring only monitors connected strings.
Battery state detection
The battery can be in one of three possible states: discharge, float or charge.
The battery state is determined by monitoring the string currents. Note the string current is
measured with a 1s filter and is therefore resistant to being affected by noise and high frequency
ripple.
The following parameters can be set :
•
Float current threshold 2-20A
• Dwell time 0-300s
Float current threshold is the limiting current above which the string is determined to be in
charge or discharge as appropriate. If say 3A is specified then float is b 3A and -3A.
Dwell time is the time the current must be continuously one side of the threshold current before
the appropriate state is detected.
Emergency OFF function
There is an emergency off function in addition to any external on/off control via an AC
contactor.
A web-based command, SNMP command, or digital input signal will cause the EFX48 to
disconnect all connected battery strings. The command is not remembered through a power
cycle.