G3H203SNDC524 Datasheet, PDF (2/12 Pages) Omron Electronics LLC – Solid State Relays Technical Information

Precautions and Notes on Correct Use
!WARNING
Do not touch the SSR terminal section (charged section) when the
power supply is ON. For SSRs with terminal covers, be sure to at-
tach the cover before use. Touching the charged section may
cause electric shock.
Do not touch the SSR or the heat sink either while the power sup-
ply is ON, or immediately after the power is turned OFF. The SSR/
heat sink will be hot and will cause burns.
Do not touch the SSR LOAD terminal immediately after the power
is turned OFF. The internal snubber circuit is charged and may
cause electric shock.
• Do not apply excessive voltage or current to the SSR input or out-
put circuits, or SSR malfunction or fire damage may result.
• Do not operate if the screws on the output terminal are loose, or
heat generated by a terminal error may result in fire damage.
• Do not obstruct the air flow to the SSR or heat sink, or heat gener-
ated from an SSR error may cause the output element to short, or
cause fire damage.
• Be sure to conduct wiring with the power supply turned OFF, or
electric shock may result.
• Follow the Correct Use section when conducting wiring and solder-
ing. If the product is used before wiring or soldering are complete,
heat generated from a power supply error may cause fire damage.
• When installing the SSR directly into a control panel so that the
panel can be used as a heat sink, use a panel material with low
thermal resistance such as aluminum or steel. If a material with
high thermal resistance such as wood is used, heat generated by
the SSR may cause fire or burning.
I Before Using the SSR
Unexpected events may occur before the SSR is used. For this rea-
son it is important to test the SSR in all possible environments. For
example, the features of the SSR will vary according to the product
being used.
All rated performance values listed in this catalog, unless otherwise
stated, are all under the JIS C5442 standard test environment (15° to
30°C, 25% to 85% relative humidity, and 86 to 106 kPa atmosphere).
When checking these values on the actual devices, it is important to
ensure that not only the load conditions, but also the operating envi-
ronmental conditions are adhered to.
I Zero Cross Function
An SSR with a zero cross function operates when the AC load volt-
age approaches the zero point or its vicinity, and releases when the
current reaches the zero point. An SSR with a zero cross function
reduces clicking noises that may be generated when the load is
turned ON.
I Life Expectancy (MTTF)
The mean time to failure (MTTF) of SSRs is 100,000 hours, which
varies with the operating conditions. To ensure long life and stable
operation, take proper countermeasures against extremely high or
low operating temperature, heavy fluctuations of ambient tempera-
ture, and/or long continuous energization.
I Input Circuit
Input Noise
SSRs need only a small amount of power to operate. This is why the
input terminals must shut out electrical noise as much as possible.
Noise applied to the input terminals may result in malfunction. The
following describes measures to be taken against pulse noise and
inductive noise.
Pulse Noise
A combination of capacitor and resistor can absorb pulse noise
effectively. The following is an example of a noise absorption circuit
with capacitor C and resistor R connected to an SSR incorporating a
photocoupler.
Pulse width
R
C
Pulse voltage
The value of R and C must be decided carefully. The value of R must
not be too large or the supply voltage (E) will not be able to satisfy
the required input voltage value.
The larger the value of C is, the longer the release time will be, due to
the time required for C to discharge electricity.
Output (load voltage)
Input
ON
OFF
Pulse voltage (V)
Note: For low-voltage models, sufficient voltage may not be applied to
the SSR because of the relationship between C, R, and the in-
ternal impedance. When deciding on a value for R, check the
input impedance for the SSR.
Solid State Relays Technical Information
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