Alpha Technologies Cordex Controller Ver.2.0 - Manual (Page 56)

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Alpha Technologies Ltd. 034-136-C0 Rev B WC
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Example 1: Add More Rectifiers Alarm
The function of the following equation is to activate a custom alarm when load increases to a
point where redundancy is compromised, but before any rectifiers go into power limit.
Enter the equation taking into consideration logic operators and the number and type of
brackets used:
[Load Current] > ((([# Acquired Rectifiers]-1)*55)-5.5)
Where 1 is the number of redundant rectifiers, 55 is the max output current of a single rectifier before
going into power limit (3kW PFM in this case), and 5.5 is the number of excess amps in the system
required for battery float charging, LVD coils or anything that draws current from the rectifiers that is
not the load.
Example 2: Generator ON/OFF Control
The function of the following equations will establish a pair of custom alarms that will activate
one relay to start a secondary generator and another relay that stops the generator.
2a) Custom Alarm A to start a secondary generator:
( (V2 <= 46) & (D8 = 0) & (D7 = 0) ) | (V2 < 44.5)
When battery is discharged (system voltage (V2) is less than 46V) and primary (D7) and secondary
(D8) generators are not on, OR system voltage is very low, activate. This alarm is exclusively mapped
to a relay that is used to start the secondary generator.
2b) Custom Alarm B to stop a secondary generator:
( ( I2 <= 6 ) & (V2 > 53) & ( D8=1) ) | ( D7= 1)
When battery is charged (battery current (I2) is low and system voltage (V2) is near normal) OR
primary (D7) generator is on, activate. This alarm is exclusively mapped to a relay that is used to stop
the secondary generator.
Example 3: AC Voltage Reading in Mixed Rectifier Systems
The following scenario involves a CXC controlling Pathfinder 10kW rectifiers and Cordex 3.6kW
rectifiers in a system with 277Vac. The CXC will compute the average AC reading of all
rectifiers (for the AC MAINS HIGH/LOW alarms). In a PFM-CXR system, it may be desirable to
have a separate AC alarm for each rectifier type.
To create separate alarms, first use the rectifier Phase Mapping feature (6.3.4) to assign each
group of rectifiers to a different phase.
NOTE: the three individual phase voltages will no longer apply; instead, the average of
the AC input voltage on each system would be given.
Next, disable the regular AC alarms (6.5.3.5).
Finally, create custom alarms using the average phase voltages. Here is one possible equation:
([Average AC Phase R] < 240) | ([Average AC Phase R] > 300)