G3H203SNDC524 Datasheet, PDF (4/12 Pages) Omron Electronics LLC – Solid State Relays Technical Information

I Output Circuit
AC ON/OFF SSR Output Noise Surges
If there is a large voltage surge in the AC current being used by the
SSR, the C/R snubber circuit built into the SSR between the SSR
load terminals will not be sufficient to suppress the surge, and the
SSR transient peak element voltage will be exceeded, causing over-
voltage damage to the SSR.
Only the following models have a built-in surge absorbing varistor:
G3NA, G3S, G3PA, G3NE, G3NH, G3DZ (some models), G3RZ, and
G3FM. When switching an inductive load with any other models, be
sure to take countermeasures against surge, such as adding a surge
absorbing element.
In the following example, a surge voltage absorbing element has
been added.
Varistor
Load
Varistor
Select an element which meets the conditions in the following table
as the surge absorbing element.
Voltage
10 to 120 VAC
200 to 240 VAC
380 to 480 VAC
Varistor voltage
240 to 270 V
440 to 470 V
820 to 1,000 V
Surge resistance
1,000 A min.
DC ON/OFF SSR Output Noise Surges
When an L load, such as a solenoid or electromagnetic valve, is con-
nected, connect a diode that prevents counter-electromotive force. If
the counter-electromotive force exceeds the withstand voltage of the
SSR output element, it could result in damage to the SSR output ele-
ment. To prevent this, insert the element parallel to the load, as
shown in the following diagram and table.
Load
(Reference)
1. Selecting a Diode
Withstand voltage = V_RM ≥ Power supply voltage × 2
Forward current = I_F ≥ load current
2. Selecting a Zener Diode
Zener voltage =
Vz < SSR withstand voltage – (Power supply voltage + 2 V)
Zener surge power =
P_RSM > Vz × Load current × Safety factor (2 to 3)
Note: When the Zener voltage is increased (Vz), the Zener diode ca-
pacity (P_RSM) is also increased.
I Application Circuit Examples
Connection to Sensors
The SSR connects directly to a Proximity Sensor or Photoelectric
Sensor.
(Brown)
Sensor ^(Black)
(Blue)
Sensors: TL-X Proximity Sensor
E3S Photoelectric Sensor
Switching Control of Incandescent
Lamps
As an absorption element, the diode is the most effective at sup-
pressing the counter-electromotive force. The release time for the
solenoid or electromagnetic valve will, however, increase. Be sure to
check the circuit before use. To shorten the time, connect a Zener
diode and a regular diode in series. The release time will be short-
ened at the same rate that the Zener voltage (Vz) of the Zener diode
is increased.
Absorption Element Example
Absorption
element
Diode
Diode +
Varistor
CR
Zener diode
Effective- O
O
X
ness
Input
signal
source
Incandes-
cent lamp
Temperature Control of Electric
Furnaces
Input signal
source and
Temperature
Controller
INPUT
Load
heater
Solid State Relays Technical Information
831