Datasheet

Solid State Relays Common Precautions
8. Inverter Load
Do not use an inverter-controlled power supply as the load
power supply for the SSR. Inverter-controlled waveforms
become rectangular, so the dV/dt ratio is extremely large and
the SSR may fail to release.
An inverter-controlled power supply may be used on the input
side provided the effective voltage is within the normal
operating voltage range of the SSR.
9. Capacitive Load
The supply voltage plus the charge voltage of the capacitor is
applied to both ends of the SSR when it is OFF. Therefore, use
an SSR model with an input voltage rating twice the size of the
supply voltage. Limit the charge current of the capacitor to less
than half the peak inrush current value allowed for the SSR.
10. SSR for DC Switching
Connection
With the SSR for DC switching, the load can be connected to
either negative (-) or positive (+) output terminal of the SSR.
Protective Component
Since the SSR does not incorporate an overvoltage absorption
component, be sure to connect an overvoltage absorption
component when using the SSR under an inductive load.
■Load Power Supply
1. Rectified Currents
If a DC load power supply is used for full-wave or half-wave
rectified AC currents, make sure that the peak load current does
not exceed the maximum usage load power supply of the SSR.
Otherwise, overvoltage will cause damage to the output element
of the SSR.
2. Operating Frequency for AC Load Power Supply
The operating frequency range for an AC load power supply is 47
to 63 Hz.
3. Low AC Voltage Loads
If the load power supply is used under a voltage below the
minimum operating load voltage of the SSR, the loss time of the
voltage applied to the load will become longer than that of the
SSR operating voltage range. See the following load example.
(The loss time is A < B.)
Before operating the SSR, make sure that this loss time will not
cause problems.
If the load voltage falls below the trigger voltage, the SSR will not
turn ON, so be sure to set the load voltage to 75 VAC min.
4. Phase-controlled AC Power Supplies
Phase-controlled power supply cannot be used.
■Operating and Storage Environments
1. Operating Ambient Temperature
The rated value for the ambient operating temperature of the
SSR is for when there is no heat build-up. For this reason, under
conditions where heat dissipation is not good due to poor
ventilation, and where heat may build up easily, the actual
temperature of the SSR may exceed the rated value resulting in
malfunction or burning.
When using the SSR, design the system to allow heat dissipation
sufficient to stay below the “●Load Current vs. Ambient
Temperature” characteristic curve. Note also that the ambient
temperature of the SSR may increase as a result of
environmental conditions (e.g., climate or air-conditioning) and
operating conditions (e.g., mounting in an airtight panel).
2. Transportation
When transporting the SSR, observe the following points. Not
doing so may result in damage, multifunction, or deterioration of
performance characteristics.
3. Vibration and Shock
Do not subject the SSR to excessive vibration or shock.
Otherwise the SSR may malfunction and internal components
may be damaged.
To prevent the SSR from abnormal vibration, do not install the
SSR in locations or by means that will subject it to vibration from
other devices, such as motors.
4. Solvents
Do not allow the SSR to come in contact with solvents, such as
thinners or gasoline. Doing so will dissolve the markings on the
SSR.
5. Oil
Do not allow the SSR terminal cover to come in contact with oil.
Doing so will cause the cover to crack and become cloudy.
ΔV/ΔT = dV/dt: voltage increase ratio The dV/dt ratio tends to infinity,
so the SSR will not turn OFF.
Peak voltage
SSR operating
voltage maximum
value
A and B: Loss time
B
0
A
Trigger voltage
Trigger voltage
Voltage waveform
Current waveform
An inductance (L) load
causes a current phase delay
as shown on the left.
Therefore, the loss is not as
great as that caused by a
resistive (R) load.
This is because a high
voltage is already imposed on
the SSR when the input
current to the SSR drops to
zero and the SSR is turned
OFF.
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