87
CET Electric Technology
It should be noted that the
Voltage ON and Voltage Alarm Limits
are calculated based on
Nominal
Voltage
, which is defined as the
a)
Nominal ULN Voltage (Modbus Register 6001)
in Firmware V1.00.09 or before
.
b)
Mains-I/II PT Secondary (ULL) (Modbus Registers 6043 and 6046, respectively)
in Firmware
V1.00.10 or later,
replacing
Nominal ULN Voltage in pervious Firmware versions.
The Mains-I
and Mains-II Voltage Alarms will be evaluated against their respective Mains-I/II PT Secondary
(ULL) values. Also, the Nominal Voltage will be adjusted internally for the ULN and ULL Alarms
accordingly, where ULL-I/II Nominal Voltage = Mains-I/II PT Secondary and ULN-I/II Nominal
Voltage = Mains-I/II PT Secondary ÷
√
3.
Therefore, it’s critical to set the
Nominal Voltage
correctly for the
Voltage ON/OFF Status, Voltage
Alarms,
as well as the
Dip/Swell
and
Interruption Alarms
(discussed in Section 4.3.12)
to work properly
.
Voltage-I/II ON Limit = Mains-I/II Nominal Voltage x 10%
Voltage-I/II OFF Limit = Voltage-I/II ON Limit x (1 – Universal Hysteresis)
Voltage H/L Alarm Limits are specified in Volt as illustrated in the Table below.
Voltage H Alarm Return Limit = Voltage H Alarm Limit x (1 – Universal Hysteresis)
Voltage L Alarm Return Limit = Voltage L Alarm Limit x (1 + Universal Hysteresis)
The following table illustrates the Voltage Alarm parameters, which apply to both Mains-I and Mains-II.
Parameters
Description
Range/Option
Default Value
ULN Alarm Enable
Bit 0 = Mains-I, Bit 1 = Mains-II
Bits 2 - 15 = Reserved
0 = Disabled
1 = Enabled
0
ULN H Alarm Limit (V)
ULN H Alarm Limit
0 to 300V
0
ULN H Alarm Time Delay (s)
ULN H Alarm Time Delay
0 to 9999(s)
0
ULN L Alarm Limit (V)
ULN L Alarm Limit
0 to 300V
0
ULN L Alarm Time Delay (s)
ULN L Alarm Time Delay
0 to 9999(s)
0
ULL Alarm Enable
Bit 0 = Mains-I, Bit 1 = Mains-II
Bits 2 - 15 = Reserved
0 = Disabled
1 = Enabled
0
ULL H Alarm Limit (V)
ULL H Alarm Limit
0 to 500V
0
ULL H Alarm Time Delay (s)
ULL H Alarm Time Delay
0 to 9999(s)
0
ULL L Alarm Limit (V)
ULL L Alarm Limit
0 to 500V
0
ULL L Alarm Time Delay
ULL L Alarm Time Delay
0 to 9999(s)
0
Table 4-12 Voltage Alarm Parameters
The following figures illustrate the logic diagram of the Voltage Alarm ON/OFF status, respectively.
Figure 4-13 Voltage Alarm ON Logic Diagram
Figure 4-14 Voltage Alarm OFF Logic Diagram
The logic diagram of Voltage H Alarm is illustrated in Figure 4-15.
Figure 4-15 Voltage H Alarm Logic Diagram