Hitachi HIDIC MICRO-EH Applications Manual page 252

(a) Wiring to the relay output terminals
1] Life of relay contacts
Life curve of relay contacts
Figure 1 Life characteristics (125 V AC)
1000
500
100
50
20
10
AC 125 V cos φ =0.4
1
0 1
Figure 2 Life characteristics (250 V AC)
1000
500
100
50
20
10
AC 250 V cos φ =0.4
1
0 1
Figure 3 Life characteristics
1000
500
100
50
20
10
DC 30 V L/R=15 ms
1
0 1
2] Surge killer
For inductive load, connect a surge killer (condenser 0.1 µF, + resistance of approx. 100 Ω) in parallel to
the load. Also, for DC load, connect a flywheel diode.
3] Fuse
A built-in fuse is not used in this module. Install a 6 A fuse in the common to prevent the external wiring
from burning out.
For the independent contact output section, install a 2A fuse per circuit.
(b) Wiring to the transistor output terminals
4] Flywheel diode
For inductive load, connect a flywheel diode in parallel.
5] V and C terminals
Always connect a V terminal and C (common) terminal. If the module is used without connecting these
terminals, the internal flywheel diode may not function and the module may malfunction or break down.
6] Fuse
There is no built-in fuse to prevent external wiring burning. Therefore, it is recommended that a fuse be
installed externally to prevent the external wiring from burning out. (This does not protect the internal
transistor elements.) If the external load is short-circuited, please contact us for repair.
AC 125 V cos φ =1
AC 125 V cos φ =0.7
2
3 4 5
Contact switching current (A)
AC 250 V cos φ =1
AC 250 V cos φ =0.7
2
3 4 5
Contact switching current (A)
DC 30 V L/R=1 ms
DV 30 V L/R=7 ms
2
3 4 5 6
Contact switching current (A)
10-7
Chapter 10 PLC Installation, Mounting, Wiring
Life of the contact is almost in squared
reverse proportion to the current, so be aware
that interrupting rush current or directly
driving the condenser load will drastically
reduce the life of the relay.
When switching is made with high
frequency, use a transistor output module.
6
6