Omron E5AZ, Руководство пользователя

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52
Using HB and HS Alarms
Section 3-10
• The setting range is 0.1 to 49.9 A. Heater burnout and HS are not
detected when the set value is 0.0 or 50.0.
When the set value is 0.0, the heater burnout alarm is always OFF, and
the HS alarm is always ON.
When the set value is 50.0, the heater burnout alarm is always ON, and
the HS alarm is always OFF.
• Set the total current value for normal heater operation to 50 A or less.
When a current value of 55.0 A is exceeded,
ffff
is displayed in the
“heater current 1 value monitor” and “leakage current 1 monitor” parame-
ters.
3-10-4 Application Examples
Single-phase Heaters Example: Using a 200-VAC, 1-kW Heater
The heater power supply provides 5 A when the current is normal, and 0 A
when there is a burnout, so the heater burnout detection current is calculated
as follows:
Example: Using Three 200-VAC, 1-kW Heaters
The heater power supply provides 15 A when the current is normal, and 10 A
when there is a burnout, so the heater burnout detection current is calculated
as follows:
CT
0 A
200 V
CT
5 A
→
←
5 A
200 V
Normal
AC line
Load Load
AC line
Product
To CT input Product
To CT input
Burnout
Load (such as a heater)
Burnout
Heater burnout detection current =
(Normal current) + (Heater burnout current)
2
=
5 + 0
2
= 2.5 [A]
10 A
10 A
CT
15 A
→
←
15 A
200 V
CT
200 V
Normal
Product
To CT input Product
To CT input
Burnout
Load Load Load
Load Load Load
Burn-
out
Heater burnout detection current =
(Normal current) + (Heater burnout current)
2
=
15 + 10
2
= 12.5 [A]