68
REVO C
2PH from 1100A to 2100A
User’s manual
Alarm description
12.1 Heater Break Alarm
This option allows you to diagnose any load breakage. The diagnostics is based on the comparison of the
value of the nominal resistance of the load with respect to the resistance measured in real time. The nominal
resistance is calculated using the
Operative Load Voltage
(
Nom Line V
) and
Nominal Current of the load
(
Nominal I
) parameters.
Nominal Resistance R=Nom Line V/Nominal I
The alarm threshold value is the value of the nominal resistance increased by the percentage defined by the
HB Sense parameter
Example:
Resistance 2200W @ 220V
power/voltage= A --> 2200/220 = 10A
• nominal V: 220 V
• nominal I: 10A
• Nominal resistance - R = 22 Ohm
HB sense parameter = 20% --> threshold value = 22 + (22 x 20 / 100) = 22+4,4 Ohm = 26,4 Ohm
22: R (V/I)
HB sense (+20%)
26,4
NO ALARM
30
25
20
15
10
5
0
Ohm
ALARM
No HB delay
22: R (V/I)
HB sense (+20%)
26,4
30
25
20
15
10
5
0
Ohm
HB delay (es: 2.5 sec.)
NO ALARM
22: R (V/I)
HB sense (+20%)
26,4
30
25
20
15
10
5
0
Ohm
HB delay (es: 2.5 sec.)
ALARM
22: R (V/I)
HB sense (+20%)
26,4
30
25
20
15
10
5
0
Ohm
12
The alarm activates when the detected Runtime resistance exceeds the value of 26.4 Ohm.
Using the HB Delay parameter, the alarm intervention can be delayed.
Sensitivity (HB sense) and delay (HB delay) can be varied according to the application (see parameters on
page 43).
