Tempco TEC-2500, Instruction Manual

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44
3–12 Heater Break Alarm
A current transformer (Part Number TEC99999) 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 0.1amp resolution. The
range of the current transformer is 0 to 50.0amp. For more detailed descriptions
about heater current monitoring, please see section 3-25.
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 level: A1SP±A1HY
Heater break alarm 2
Setup: IN2=CT
A2FN=PV2.L
A2MD=NORM
A2HY=0.1
Adjust: A2SP
Trigger level: A2SP±A2HY
Limitations:
1. Linear output can't use heater
break alarm.
2. CYC1 should use 1 second or
longer to detect heater current
reliably.