Omron E5CN User Manual page 48

Wiring Terminals
Alarm Outputs 1, 2, and 3
26
• Long-life relay outputs use semiconductors for switching when closing
and opening the circuit, thereby reducing chattering and arcing and
improving durability. However, if high levels of noise or surge are imposed
between the output terminals, short-circuit faults may occasionally occur.
If the output becomes permanently shorted, there is the danger of fire due
to overheating of the heater. Design safety into the system, including
measures to prevent excessive temperature rise and spreading of fire.
Take countermeasures such as installing a surge absorber. As an addi-
tional safety measure, provide error detection in the control loop. (Use the
Loop Break Alarm (LBA) and HS alarm that are provided for the E5@N.)
Long-life
relay output
1
Varistor
2
Select a surge absorber that satisfies the following conditions.
Voltage used
100 to 120 VAC
200 to 240 VAC
• On the E5CN-@2@@@, alarm output 1 (ALM1) is output across terminals
7 and 8, and alarm output 2 (ALM2) is output across terminals 6 and 8.
• On the E5CN-@1@@@U, alarm output 1 (ALM1) is output across termi-
nals 7 and 8.
• On the E5CN-@2@@@U, alarm output 1 (ALM1) is output across termi-
nals 7 and 8, and alarm output 2 (ALM2) is output across terminals 7 and
9.
• On the E5AN/EN-@3@@@, alarm output 1 (ALM1) is output across termi-
nals 9 and 10, alarm output 2 (ALM2) is output across terminals 7 and 8,
and alarm output 3 (ALM3) is output across terminals 5 and 6.
• When the "input error output" parameter is set to ON, alarm output 1 turns
ON when an input error occurs.
• When the HBA or the HS alarm is used with the E5CN-@@H@ or the
E5CN-@@HH@, alarms are output across terminals 7 and 8.
• When the HBA or the HS alarm is used with the E5CN-@@H@@, alarms
are output across terminals 9 and 10.
• On the E5CN and E5CN-U, when heating/cooling control is used, alarm
output 2 becomes control output (cooling).
• On the E5AN and E5EN, when heating/cooling control is used, alarm out-
put 3 becomes control output (cooling).
• For models that have a heater burnout alarm, an OR of alarm output 1
and the HBA/HS alarm is output. If ALM1 is to be used for HBA only, set
the alarm 1 type to 0 and do not use alarm output 1.
• The following diagrams show the internal equalizing circuits for alarm out-
puts 1, 2, and 3.
Varistor
Inductive
load
Varistor voltage
240 to 270 V
440 to 470 V
Section 2-2
Surge resistance
1,000 A min.