Panasonic ASCT1F46E - Manual (Page 12)

11
8. Water
resistance
Select the sealed-type for exposure to water. In the case of water exposure in severe conditions or
immersion, please verify water resistance of the relay or contact us. Even for sealed-type relays, its
terminals are not waterproof, so please avoid a failure such as terminal corrosion.
Note that moisture adhered on relay in a due condensation or a high humidity condition freezes when
the temperature is lower than 0°C. This may cause problems such as sticking of movable parts or
operational time lags, or poor contact conduction. Therefore, please test them in actual use
environment. 9. Freezing
Note that if a relay is connected or installed with a high heat-capacity such as bas bar, connector,
harness, and PCB, heat removal phenomenon will accelerate cooling of the relay inside and promote
freezing. So, please verify in actual installation condition.
12. Usage
ambient
condition
10. Low
temperature,
low humidity
The plastic becomes brittle if the relay is exposed to a low temperature, low humidity environment for
long periods of time.
Please consider the vibration at installation area to avoid loosely-contact.
Also, note that even a microscopic vibration may cause contact failure at the contact area of relay
terminal and connector.
Decrease of fitting performance of connector may cause abnormal heat at connector contact area
depending on use temperature and applying heat. Sufficient margin of safety must be provided in
selection of a connector.
13.Installation 1. Connector
installation
Please select the proper material of connector and surface treatment to avoid corrosion at the contact
area of relay terminal and connector and increase of resistance at connecting area which may be
caused depending on ambient environment.
14. PC board
design
1. PC board
design
consideration
1. Cautions regarding Pattern Layout for Relays
Since relays affect electronic circuits by generating noise, the following points should be noted.
•
Keep relays away from semiconductor devices.
•
Design the pattern traces with the shortest length.
•
Place the surge absorber (diode, etc.) near the relay coil.
•
Avoid routing pattern traces susceptible to noise (such as for audio signals) underneath the
relay coil section.
•
Avoid through-holes in places which cannot be seen from the top (e.g. at the base of the
relay). Solder flowing up through such a hole may cause damage such as a sealing failure.
•
Even for the same circuit, it is necessary to consider the pattern design in order to minimize
the influence of the on/off operations of the relay coil and lamp on other electronic circuits, as
shown in the figure below.
-Relay currents and electronic circuit
currents flow together through A and B.
-Relay coil currents consist only of A1 and B1.
-Electronic circuit currents consist only of A2
and B2. A simple design can change safety of
the operation.