3 11 Heater Break Alarm
3 11 Heater Break Alarm
A current transformer ( parts No.
) should be installed to detect the
heater current if a heater break alarm is required. The CT signal is sent to
input 2, and the PV2 will indicate the heater current in 0.1 Amp. resolution.
The range of the current transformer is 0 to 50.0 Amp.
For a more detailed description about heater current monitoring, please see
CT94-1
Section 3-24.
A current transformer ( parts No.
) should be installed to detect the
heater current if a heater break alarm is required. The CT signal is sent to
input 2, and the PV2 will indicate the heater current in 0.1 Amp. resolution.
The range of the current transformer is 0 to 50.0 Amp.
For a more detailed description about heater current monitoring, please see
CT94-1
Section 3-24.
Example:
A furnace uses two 2KW heaters connected in parallel to warm up the process.
The line voltage is 220V and the rating current for each heater is 9.09A. If we
want to detect any one heater break, set A1SP=13.0A, A1HY=0.1
A1FN=PV2.L, A1MD=NORM, then
Example:
A furnace uses two 2KW heaters connected in parallel to warm up the process.
The line voltage is 220V and the rating current for each heater is 9.09A. If we
want to detect any one heater break, set A1SP=13.0A, A1HY=0.1
A1FN=PV2.L, A1MD=NORM, then
Heater Break Alarm 1
Setup : IN2 = CT
A1FN = PV2.L
A1MD = NORM
A1HY = 0.1
Adjust : A1SP
Trigger levels : A1SP ±1/2 A1HY
Heater Break Alarm 1
Setup : IN2 = CT
A1FN = PV2.L
A1MD = NORM
A1HY = 0.1
Adjust : A1SP
Trigger levels : A1SP ±1/2 A1HY
Limitations :
1. Linear output can't use heater break
alarm.
2. CYC1 should use 1 second or
longer to detect heater current reliably.
Limitations :
1. Linear output can't use heater break
alarm.
2. CYC1 should use 1 second or
longer to detect heater current reliably.
0
10
20
30
40
50
A
0
10
20
30
40
50
A
0
10
20
30
40
50
A
Normal process
Normal process
1 heater breaks
1 heater breaks
2 heaters break
2 heaters break
Alarm !
Alarm !
Alarm !
Alarm !
Figure 3.17
Heater Break Alarm
Figure 3.17
Heater Break Alarm
Heater Break Alarm 2
Setup : IN2 = CT
A2FN = PV2.L
A2MD = NORM
A2HY = 0.1
Adjust : A2SP
Trigger levels : A2SP ±/2 A2HY
Heater Break Alarm 2
Setup : IN2 = CT
A2FN = PV2.L
A2MD = NORM
A2HY = 0.1
Adjust : A2SP
Trigger levels : A2SP ±/2 A2HY
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