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 env iro nment
- 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)