Automotive relay user’s guide – Panasonic ASCT1F46E User Manual

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Automotive Relay User’s Guide


Please use the check sheet.

1

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

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