System Operation
Copyright © 2007-2011 Eaton Corporation. All Rights Reserved.
IPN 997-00012-50H November 2011
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Load Based Rectifier Shutdown
Load Based Rectifier Shutdown is not available with APR48-3G (prior to PR5), EPR48-3G,
APR24-3G and CR48-3G rectifiers.
If Load Based Rectifier Shutdown (LBRS) is enabled by setting
Shutdown
to
Automatic
then the
SC200 automatically shuts down rectifiers when the total load current is significantly less than
the total rectifier capacity.
This raises the average load on the remaining rectifiers which will then operate at a higher
efficiency. This results in a decrease in system power consumption.
The SC200 shuts down APR48-3G PR5 rectifiers before the more efficient APR48-ES rectifiers.
The run time of all rectifiers is recorded and the usage within each group of rectifiers (APR48-
3G PR5s and APR48-ESs) is balanced to ensure even aging.
The SC200 will progressively restart rectifiers (starting with any shut down APR48-ES rectifiers)
if the load increases.
Rectifiers shut down by LBRS will have the yellow LED on.
At least two rectifiers will always be on to maintain N+1 rectifier redundancy. Therefore, LBRS
has no effect in dc power systems with only one or two rectifiers.
The SC200 will automatically restart all rectifiers if ac supply has failed, or more than one rectifier
has failed, or Battery Test / Equalize / Fast Charge are active, or the bus voltage is below the Low
Load threshold.
► To enable Load Based Rectifier Shutdown
Use the SC200 keypad to go to: Rectifiers > Settings (tab) > set Rectifier Shutdown to
Automatic.
Or, in DCTools/Web go to: Rectifiers > set Shutdown to Automatic.
Ensure that Rectifier Start Up Delay is less than 30 seconds. See information on page
will not function correctly if the start up delay is more than 30 seconds.
Information
The following information is available about Load Based Rectifier Shutdown.
Parameter
Description
Where to find:
Load Based Run
Time
The run time of each rectifier
DCTools/Web: Rectifiers
Configuration
The following parameters must be configured to set Load Based Rectifier Shutdown.
Parameter
Description
Where to find:
Reset Run Times
Sets the run time of all rectifiers to zero.
SC200: Rectifiers > Settings
(tab) > LBRS
DCTools/Web: Rectifiers >
Load Based Rectifier
Shutdown
High Threshold
LBRS restarts all rectifiers if the load is more
than this percentage of the total rectifier capacity.
Typical: 60%.
Low Threshold
LBRS shuts down rectifiers if the load is less than
this percentage of the total rectifier capacity.
Typical: 40%.
Interval
The time interval that the SC200 will cycle
rectifiers when the LBRS process is active.
