Load
3
13. Load
voltage
If the load voltage is high, the arc energy which generated at contact switching increases, which may
decrease the electrical life. Therefore, it is necessary to give consideration to the voltage which could
occur in actual use condition.
14. Coil voltage If coil applied voltage gets higher, the relay operate time gets faster. However, contact bounce gets also
larger so that the electrical life may decrease.
15. Coil
short-pulse
input
When the short-pulse signal is input to the relay coil, the relay movable part may operate and touch
lightly to the contact. Therefore, please avoid short pulse input (100ms or less) since it may cause
contact welding due to less contact pressure. Please test adequately, for example when a relay is
operated by external manual switch (such as key switch.)
16. High-
frequency
of switching
When the switching frequency is high, the electrical life may decrease. Please confirm if there is a
high-frequent switching caused by abnormal mode in actual use condition.
17. Low-
frequency
of switching
Note that if the contact has not been switched for a long time period, organic film tends to be generated
on the contact surface, which may cause contact instability.
18. Ambient
temperature
Verify in the actual use condition since electrical life may be affected by use at high temperatures.
19. Connection
of coil surge
absorption
circuit
If resistor, diode, zener diode are connected parallel to decrease the surge voltage when the relay coil
being turned off, the relay release time will get longer and may decrease the electrical life or cause
light-welding.
20. Sneak or
remaining
current
Please test a relay in actual vehicle condition since there is a risk of deterioration at relay function or
switching performance such as slower release time which is caused by sneak current due to diode,
zener diode, capacitor mounted on a vehicle or by remaining current soon after a motor is turned off.
4. Load,
Electrical
life
21. Wire length
If long wires (a few ten meters) are to be used in a relay contact circuit, inrush current may become a
problem due to the stray capacitance existing between wires. In such case, add a resistor in series with
the contacts.
