Panasonic ASCT1F46E User Manual

Page of 26
Automotive Relay User’s Guide 
 
 
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Category Section 
Contents 
1. Confirmation 
under the 
actual use 
condition  
1. Confirmation 
under the 
actual use 
The rated switching power and life mentioned in the specification and catalog are given only as guides. A 
relay may encounter a variety of ambient conditions during actual use resulting in unexpected failure. 
Therefore, it is necessary for proper use of the relay to test and review with actual load and actual 
application under actual operating conditions. 
1. Specification 
range 
Use that exceeds the specification ranges such as the coil rating, contact rating and switching life should 
be absolutely avoided. Doing so may lead to abnormal heating, smoke, and fire. 
2. Installation, 
maintenance 
Never touch live parts when power is applied to the relay. Doing so may cause electrical shock. When 
installing, maintaining, or troubleshooting a relay (including connecting parts such as terminals and 
sockets), be sure that the power is turned off.   
3. Connection 
When connecting terminals, please follow the internal connection diagrams in the catalog to ensure that 
connections are done correctly. Be warned that an incorrect connection may lead to unexpected 
operation error, abnormal heating, and fire. 
2. Safety 
precautions 
4. Fail-safe 
If there is a possibility that adhesion, contact failure, or breaking of wire could endanger assets or human 
life, please make sure that a fail-safe system is equipped in the vehicle. 
3. Selection of 
relay type 
1. Selection   
In order to use the relays properly, the characteristics of the selected relay should be well known, and the 
conditions of use of the relay should be investigated to determine whether they are matched to the 
environmental conditions, and at the same time, the coil specification, contact specification, and the 
ambient conditions for the relay that is actually used must be fully understood in advance.   
In the table below, please refer to a summary of the consideration points regarding selection of relay. 
Items   
Consideration points regarding selection   
Coil 
a) Rating   
b) Pull-in voltage 
(current) 
c) Drop-out voltage 
(current) 
d) Maximum continuous 
impressed voltage 
(current) 
e) Coil resistance 
f ) Temperature rise 
- Select relay with consideration for power source ripple. 
- Give sufficient consideration to ambient temperature 
and for the coil temperature rise, and hot start. 
- When used in conjunction with semiconductors, careful 
with the voltage drop. 
- When starting up, careful with the voltage drop. 
Contact 
a) Contact arrangement
b) Contact rating 
c) Contact material 
d) Life 
e) Contact resistance 
- Note that the relay life is balanced with the life of the 
device the relay is used in.   
- Is the contact material matched to the type of load? It is 
necessary to take care particularly with low level usage.
- The rated life may become reduced when used at high 
temperatures. Life should be verified in the actual use 
atmosphere.  
- It is necessary to be tested and reviewed under actual 
use conditions with actual load and actual application. 
Operate time 
a) Operate time 
b) Release time 
c) Bounce time 
d) Switching frequency 
- Note that ambient temperature and applied voltage 
cause the change of operate time and bounce time. 
- Note that operate time and release time do not include 
bounce time.   
- Give consideration that switching life changes 
depending on switching frequency.   
Mechanical 
characteristics 
a) Vibration resistance 
b) Shock resistance 
c) Ambient use 
temperature 
d) Life 
- Give consideration to performance under vibration and 
shock in the use location. 
- Confirm the allowable ambient temperature of the relay.
Other items 
a) Breakdown voltage 
b) Mounting, 
Connection 
c) Size 
d) Protection 
construction 
- Selection can be made for connection method with 
plug-in type, printed circuit board type, soldering, and 
screw fastening type. 
- Selection of protection construction can be made for 
PCB mounting method such as soldering and cleaning. 
- For use in an adverse atmosphere, sealed construction 
type should be selected. 
- Are there any special conditions? 
 
Panasonic Electric Works 
Obihiro Co., Ltd.
Oct. 1, 2008: 1
st
Edition