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M800S/M80/E80 Series Connection and Setup Manual
4 General Specifications
Precautions
(1) Influence on the relay life by a connected load
An actual relay life can be substantially shortened depending on the type of a connected load and the
characteristics of its inrush current.
The inrush current generated by a connected load can lead to contact welding of the module. To prevent
shortening of the relay life and contact welding, take the following measures:
・ Considering the possibility of a high inrush current, select a load so that the inrush current generated by
the connected load falls within the range of the rated current of the module.
・Connect a relay capable of withstanding the inrush current, outside the module.
The following table lists the relations between typical loads and each inrush current.
Select a load so that the inrush current, i, and rated current, io, fall within the range of the rated switching
current described in the module specifications.
n some loads, the inrush current flows for a long time.
Load type
Inductive
load
Lamp load
Capacitive
load
(Note 1) A typical discharge lamp circuit is configured with a combination of discharge tubes,
(Note 2) When the wiring is long, be careful with the cable capacity as well.
IB-1501269-J
Waveform
Load of a solenoid
i
io
i: Inrush current
io: Rated current
0.07 to 0.1 seconds
Load of an incandescent bulb
i
io
i: Inrush current
io: Rated current
Approx. 0.33 seconds
Load of a fluorescent
i
io
i: Inrush current
io: Rated current
Within 10 seconds
Capacitive load (Note 2)
i
io
i: Inrush current
io: Rated current
0.008 to 0.33 seconds
(0.5 to 2 cycles)
transformers, choke coils, capacitors and others. Because of this, be especially careful of the
case of a high power factor and a low power supply impedance, where the inrush current
flowing into the output module can be 20 to 40 times as high as the rated current.
Inrush
current i/
rated current
io
Load of an electromagnetic contactor
Approx. 10 to
i
20 times
Load of a mercury lamp
Approx. 3 to
i
10 times
Approx. 5 to
-
10 times
Approx. 20 to
-
40 times
138
Inrush
current i/
Waveform
rated current
io
i: Inrush current
Approx. 3 to
io: Rated current
io
10 times
0.017 to 0.033 seconds
(1 to 2 cycles)
Approx. 3
io
times (Note
1)
i: Inrush current
io: Rated current
180 to 300 seconds
(3 to 5 minutes)
-
-
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