Alpha Technologies Cordex Controller Ver.3.1x - Manual (Page 67)

65 0700015-J0 Rev B
The previous notes correspond to the numbers in the sequence of figures below:
Equations (from actual customer configurations)
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)*37)-5.5)
Where 1 is the number of redundant rectifiers, 37 is the max output current of a single rectifier (Cordex
HP 2.0kW in this example) before going into power limit (2 kW PFM), 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 establish a pair of custom alarms that 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 the 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 a battery is charged (battery current (I2) is low and system voltage (V2) is near normal) OR pri-
mary (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 10 kW rectifiers and Cordex 3.6 kW recti-
fiers in a system with 277 Vac. 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 (6.3.3.4) to assign each group of
rectifiers to a different phase. The three individual phase voltages will no longer apply; instead, the aver-
age of the AC input voltage on each system is given.
Figure 69 — Customize Alarm example