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Home > Technology > Cautions in Applying and Installing
▶ Transportation and Installation
A relay is one kind of accurate mechanism. Therefore, it is quite sensitive to inadequacy transportation style. During manufacturing, many methods are adopted to enable the relay to be well protected in transportation, so that the user should not damage the original performance of the relay during checking-in and installing as well as operating. Besides these, the user should pay attention to the following points:
1. To prevent contamination on the surface of the leading-out terminal, don't touch the leading-out terminal directly. Otherwise, it will cause the weld ability to deteriorate.
2. The positions of the leading-outs should tally with the holes on the printed circuit. Any inadequacy of matching will cause dangerous stress in the relay and damage its performance and reliability. Please, drill holes referring to the pattern of the sample.
3. To monitor the storage temperature. To avoid too long storage period of the relay (recommended period, not more than three months).
4. The relay should be stored and installed in clean environment.
▶ Pasting welding agent
A non-plastic packaging relay may be contaminated easily by the welding agent. We advise the user to use counter-welding-agent type or plastic-packaging-type relay to prevent welding gas intruding from the gap between leading-out terminal and the socket. This kind of relay is fit for technology with foamy pasting welding agent and spray pasting welding agent. If the relay of counter-welding type is dried with preheating method, it will prevent welding-agent intruding further more.
▶ Welding Technology
When the technology of pasting welding-agent or auto-welding is applied, one should be careful not to damage the relay performance. A relay of counter-welding-agent type or plastic-packaging-type is suitable for the technology of dip soldering or wave soldering, but the highest welding temperature and the longest welding time should be controlled according to different relays selected.
▶ Washing Technology
Avoid bulk-washing to a relay of non-plastic-packaging type. The plastic-packaging type relay is to be washed with adequate cleaning agent. Alcohol is recommended. Avoid washing it with ultra-sonic wave as much as possible. It is because the harmonic wave of the ultra-sonic frequency may cause cold welding and even may cause the contacts seized-up.
After washing and drying, the relay should receive a ventilation to make the relay cool down to normal temperature.
▶ Installing Direction
It is quite important to install the relay in correct direction for optimum performance.
1. Impact-resistance
The ideal installing direction is that in which the direction of the contact and moveable unit (armature iron) is perpendicular to the direction of vibration or impact. Especially, when the coil is not excited, the performance of counter-vibration and impact-resistance for the normally open contact is greatly affected by the installing direction.
2. Reliability of the contact
The installing direction of the relay enables the surface of the contact to be at right angle to prevent pollution material and dust falling onto the surface of the contact. It is inadequate for the same relay to switch to a heavy load and a light load, otherwise, it may affect each other.
3. Adjacent-installation
When it is necessary to install several relays side by side, it is probable to produce abnormal high temperature because of the heat superimposing. Therefore, there must be a sufficient separation space (normally, >5mm) between any two relays to prevent heat superimposing. Anyway, one should ensure that the environment temperature of the relay should not exceed the stipulated value of the sample.
4. Socket usage
When a socket is used, ensure that the socket is firmly installed. The leading-out of the relay and the socket should be in firm contact, the installing hole should fit the socket well, and the installing stand of the socket as well as the relay should be used correctly.
5. Selection of the leading wire
If it is necessary to connect the relay with a wire, select a wire with adequate cross area according to the heaviness of the load. The following table shows the current and the relevant cross area of the wire selected.
| Allowed current (A) |
Cross area of wire (mm2) |
| 2 |
0.2 |
| 3 |
0.3 |
| 5 |
0.5 |
| 7.5 |
0.75 |
| 12.5 |
1.25 |
| 15 |
2 |
| 20 |
2 |
| 30 |
3.5 |
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