*1: This ELC does not have any internal protection circuitry on the relay outputs. For switching direct
current on inductive loads, a reverse-current protection diode should be installed in parallel with the
load. The relay contact life decreases significantly if this is not done.
The reverse-current protection diode needs to satisfy the following specifications.
- The diode is rated for maximum reverse voltage of 5~10 times the load voltage.
- The forward current is more that the load current
*2: Ensure all loads are applied to the same side of each ELC output, see above figure. Loads which
should NEVER simultaneously operate(e.g. direction control of a motor), because of a critical safety
situation, should not rely on the ELC’s sequencing alone. Mechanical interlocks MUST be fitted to all
critical safety circuits.
*3: This ELC does not have any internal protection circuitry on the relay output. For switching AC on
inductive loads, a surge absorber (0.1uF + “100ohm to 120ohm”) should be installed in parallel with
the load. The relay contat life decreases significantly if this is not done. Besides protecting the
internal circuity of the ELC, a surge absorber decreases the noise emissions to the load.
The Transistor Output Circuit Wiring
1 Do not use this terminal
2 Emergency Stop
3 Fuse
4 External Mechanical Interlock
5 DC Power Supply
6 Incandescent Lamp
7 Reverse-current protection diode, *1
8 Inductive load
0&
0&
&
&
<
<
&
<
<
<
<
5
7
8
1
6
6
4
0&
0&
2
3
3
9
9 Resistive load
*1: Ensure all loads are applied to the same side of each ELC output, see above figure. Loads which
should NEVER simutaneously operate (e.g. direction control of a motor), because of a critical safety
situation, should not rely on the ELC’s sequencing alone. Mechanical interlocks MUST be fitted to all
critical safety circuits.
*2: Transistor outputs use internal zener diode(39V) as protection circuitry. When driving the
inductive load with transistor output, a reverse-current protection diode can be installed in parallel
with the load if necessary.
The reverse-current protection diode needs to satisfy the following specifications.
- The diode is rated for maximum reverse voltage of 5 to 10 times the load voltage.
- The forward current is more than the load current.
4
TRIAL RUN
4.1. Before Turning ON the Power
After wiring, be sure to check the items below before turning ON the power supply to the ELC.
Item
Description
Unit mounting status
-
Does the unit type match the device list during the design stage?
-
Are all of the units firmly attached?
Power supply
-
Is operating voltage supplied correctly?
-
Is the power supply cable properly connected?
-
Are both voltage and polarity connected correctly for each connection
-
Protection against excess current: when overloaded, output voltage lowers.
Although the output voltage will return to normal when the load returns to normal,
be careful as long overloads or short-circuits will cause deterioration or destruction
of internal elements.
-
Attaching additional power supply units in parallel is not allowed! It may destroy
internal elements and the load of the power supply.
Check input/Output
terminals
-
Does the wiring of connector and terminal match?
-
Is the operating voltage of I/O correct?
-
Are the connectors of I/O properly connected?
-
Is the wire size correct?
Note: These precautions concern the ELC-PS01/PS02 power supply unit specifically.
