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SJ1000/2000/3000/4000
Specific Product Precautions 3
Be sure to read this before handling the products. Refer to the back cover for safety instructions.
For 3/4/5-port solenoid valve precautions, refer to the "Handling Precautions for SMC Products"
and the "Operation Manual" on the SMC website: https://www.smcworld.com
Working Principle
The circuit shown on page 139 reduces the power consumption
for holding in order to save energy. Refer to the electrical power
waveform as shown below.
Electrical power waveform of the power-saving type (SJ3m60(A)T, SJ4m60T)
Applied voltage
24 VDC
0
0.4 W
0.15 W
0 W
67 ms
Electrical power waveform of the power-saving type (SJ1m60T, SJ2m60T)
Applied voltage
24 VDC
0
0.55 W
0.23 W
0 W
67 ms
• The 12 VDC specification with power-saving circuit does not
have the polarity protection diode. Do not make a mistake with
the polarity.
• Since the voltage will drop by approx. 0.5 V due to the transis-
tor, pay attention to the allowable voltage fluctuation. (For de-
tails, refer to the solenoid specifications of each type of valve.)
Standard model
With power-
saving circuit
Standard model
With power-
saving circuit
Series
Countermeasure for Surge Voltage Intrusion
L Surge voltage intrusion
With non-polar type valves, at times of sudden interruption of
the loading power supply, such as emergency shutdown,
surge voltage intrusion may be generated from loading
equipment with a large capacity (power consumption), and a
valve in a de-energized state may switch over (see Fig. 1).
When installing a breaker circuit for the loading power supply,
consider using a valve with polarity (with polarity protection
diode), or install a surge absorption diode between the loading
equipment COM line and the output equipment COM line (see
Fig. 2).
Output circuit
R
R
R
Power supply circuit breaker
Fig. 1 Surge intrusion circuit example
(NPN outlet example) (24 VDC)
Output circuit
R
R
R
Power supply circuit breaker
Fig. 2 Surge intrusion countermeasure example
(NPN outlet example) (24 VDC)
Surge voltage
24 V
0 V
sol.1: Energized
−60 V
Surge voltage
24 V
0 V
sol.2: De-energized
−60 V
Surge voltage
24 V
0 V
Large capacity
−60 V
load: Energized
Relay
24 VDC
Surge voltage
24 V
0 V
sol.1: Energized
−2 V
Surge voltage
24 V
0 V
sol.2: De-energized
−2 V
Surge voltage
24 V
0 V
Large capacity
−2 V
load: Energized
Countermeasure
Diode
parts
– (Anode) + (Cathode)
Relay
24 VDC
SJ
1000
2000
3000
4000
SJ3A6
140
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