EE2 SERIES

11

Notes on Correct Use

1. Notes on contact load

Make sure that the contact load is within the specified range;

otherwise, the lifetime of the contacts will be shortened considerably.

Note that the running performance shown is an example, and that it

varies depending on parameters such as the type of load, switching

frequency, driver circuit, and ambient temperature under the actual

operating conditions. Evaluate the performance by using the actual

circuit before using the relay.

2. Driving relays

- If the internal connection diagram of a relay shows + and - symbols

on the coil, apply the rated voltage to the relay in the specified

direction. If a rippled DC current source is used, abnormalities such

as beat at the coil may occur.

- The maximum voltage that can be applied to the coil of the relay

varies depending on the ambient temperature. Generally, the higher

the voltage applied to the coil, the shorter the operating time. Note,

however, that a high voltage also increases the bounce of the

contacts and the contact opening and closing frequency, which may

shorten the lifetime of the contacts.

- If the driving voltage waveform of the relay coil rises and falls

gradually, the inherent performance of the relay may not be fully

realized. Make sure that the voltage waveform instantaneously rises

and falls as a pulse.

- For a latching relay, apply a voltage to the coil according to the

polarity specified in the internal connection diagram of the relay.

- If a current is applied to the coil over a long period of time, the coil

temperature rises, promoting generation of organic gas inside the

relay, which may result in faulty contacts. In this case, use of a

latching relay is recommended.

- The operating time and release time indicate the time required for

each contact to close after the voltage has been applied to or

removed from the coil. However, because the relay has a

mechanical structure, a bounce state exists at the end of the

operating and release times. Furthermore, because additional time

is required until the contact stabilizes after being in a high-resistance

state, care must be taken when using the relay at high speeds.

3. Operating environment

- Make sure that the relay mounted in the application set is used

within the specified temperature range. Use of a relay at a

temperature outside this range may adversely affect insulation or

contact performance.

- If the relay is used for a long period of time in highly humid (RH

85% or higher) environment, moisture may be absorbed into the

relay. This moisture may react with the NOx and SOx generated by

glow discharges that occur when the contacts are opened or closed,

producing nitric or sulfuric acid. If this happens, the acid produced

may corrode the metallic parts of the relay, causing operational

malfunction.

- Because the operating temperature range varies depending on the

humidity, use the relay in the temperature range illustrated in the

figure below. Prevent the relay from being frozen and avoid the

generation of condensation.

- The relay maintains constant sealability under normal atmospheric

pressure (810 to 1,200 hpa). Its sealability may be degraded or the

relay may be deformed and malfunction if it is used under barometric

conditions exceeding the specified range.

- The same applies when the relay is stored or transported. Keep the

upper-limit value of the temperature to which the relay is exposed

after it is removed from the carton box to within 50°C.

- If excessive vibration or shock is applied to the relay, it may

malfunction and the contacts remain closed. Vibration or shock

applied to the relay during operation may cause considerable

damage to or wearing of the contacts. Note that operation of a snap

switch mounted close to the relay or shock due to the operation of

magnetic solenoid may also cause malfunctioning.

4. Notes on mounting relays

- When mounting a relay onto a PC board using an automatic chip

mounter, if excessive force is applied to the cover of the relay when

the relay is chucked or inserted, the cover may be damaged or the

characteristics of the relay degraded. Keep the force applied to the

relay to within 1 kg.

- Avoid bending the pins to temporarily secure the relay to the PC

board. Bending the pins may degrade sealability or adversely affect

the internal mechanism.

- It is recommended to solder the relay onto a PC board under the

following conditions:

<1> Reflow soldering

Refer to the recommended soldering temperature profile.

<2> Flow soldering

Solder temperature: 260°C max., Time: 5 seconds max, Preheating:

100°C max./1 minute max.

<3> Manual soldering

Solder temperature: 350°C, Time: 2 to 3 seconds

- Ventilation immediately after soldering is recommended.

Avoid immersing the relay in cleaning solvent immediately after

soldering due to the danger of thermal shock being applied to the

relay.

- Use an alcohol-based or water-based cleaning solvent. Never use

thinner and benzene because they may damage the relay housing.

- Do not use ultrasonic cleaning because the vibration energy

generated by the ultrasonic waves may cause the contacts to

remain closed.

5. Handling

- Relays are packaged in magazine cases for shipment. If a space is

created in the case after some relays have been removed, be sure

to insert a stopper to secure the remaining relays in the case. If

relays are not well secured, vibration during transportation may

cause malfunctioning of the contacts.

- Exercise care in handling the relay so as to avoid dropping it or

allowing it to fall. Do not use a relay that has been dropped.

If a relay drops from a workbench to the floor, a shock of 9,800 m/s2

(1,000 G) or more is applied to the relay, possibly damaging its

functions. Even if a light shock has been applied to the relay,

thoroughly evaluate its operation before using it.

- Latching relays are factory-set to the reset state for shipment. A

latching relay may be set, however, by vibration or shock applied

while being transported. Be sure to forcibly reset the relay before

using it in the application set. Also note that the relay may be set by

unexpected vibration or shock when it is used in a portable set.

- The sealability of a surface-mount relay may be lost if the relay

absorbs moisture and is then heated during soldering. When storing

relays, therefore, observe the following points:

<1> Please use relays within 12 months after delivery. (Storage

conditions : 30 degrees C / 60% RH)

<2> For MBB packing, Please use relays within 2 years after

delivery.

(Stronge conditions : 30 degrees C / 60% RH)

After opening MBB packing, Please use within 3 months.

(Storage conditions : 30 degrees C/ 60% RH)