Current Sensor
SAO
CSM_SAO_DS_E_4_1
Solid-state, Plug-in Current Sensor
• Applicable to motor overcurrent protection and 3-phase AC cur-
rent detection.
• Inverse-type, start-up lock type, and instantaneous type over-
current sensors available.
• Instantaneous type under current sensor available.
• Plug-in design simplifies installation, removal, and wiring.
• DIN sized (48 mm x 96 mm)
The SAO cannot be used in circuits with
waveform distortion, inverter circuits, or
with capacitor loads.
Model Number Structure
■
Model Number Legend
SAO-@@@@
1
2 3 4 5
4. Control voltage
1:
100/110/120 VAC
2:
200/220/240 VAC
5:
24 VDC
6:
48 VDC
7:
100/110 VDC
5. Product history
N:
New version
1. Basic model name
SAO: Current Sensor
2. Operating time characteristics
R:
Inverse type: inverse time both at starting and during oper-
ation
Q:
Instantaneous type with start-up lock
S:
Regular instantaneous type
3. Detection function
U:
Undercurrent detection
None: Overcurrent detection
Ordering Information
Terminal/
mounting
Control voltage
Inverse type
Plug-in/DIN
rail via socket
100/110/120 VAC
200/220/240 VAC
24 VDC
48 VDC
100/110 VDC
SAO-R1N
SAO-R2N
SAO-R5N
SAO-R6N
SAO-R7N
SAO-Q1N
SAO-Q2N
SAO-Q5N
SAO-Q6N
SAO-Q7N
Overcurrent detection
Instantaneous type
W/start-up lock*
W/o start-up lock
SAO-S1N
SAO-S2N
SAO-S5N
SAO-S6N
SAO-S7N
SAO-SU1N
SAO-SU2N
SAO-SU5N
SAO-SU6N
SAO-SU7N
Under current
detection
Instantaneous type
* Fixed time-limit at start-up, instantaneous thereafter.
■
Accessories (Order Separately)
Current Converters
Model
SET-3A
SET-3B
Current range
1 to 80 A
64 to 160 A
DIN rail socket
8PFA1
Socket
Type
Front connecting socket
Model
8PFA1
1
SAO
Specifications
■
Ratings
Motor circuit
Power supply circuit
Voltage:500 VAC max. 3-phase (primary voltage at SET Current Converter)
Current:1 to 80 A or 64 to 160 A 3-phase (primary current at SET Current Converter)
Voltage: 100/110/120 VAC, 200/220/240 VAC, 24, 48 VDC, or 100/110 VDC (leveled DC)
Voltage fluctuation:
+10
/
–15
% max. of the rated voltage
Frequency: 50/60 Hz
±5%
See table of
Current Converter.
Configuration: SPDT
Capacity: 3 A (cosφ = 1.0)/2 A (cosφ = 0.4) at 240 VAC; 3 A (resistive load)/2 A (L/R = 7 ms) at 24 VDC;
0.2 A (resistive load)/0.1 A (L/R = 7 ms) at 110 VDC
100/110/120 VAC: approx. 3.5 VA; 200/220/240 VAC: approx. 7 VA;
24 VDC: approx. 0.3 W; 48 VDC: approx. 0.5 W; 100/110 VDC: approx. 1.2 W
Munsell 5Y7/1
Current SV range
Output contact
Power consumption
Case color
■
Characteristics
Item
Operating current
SAO-R@N
SAO-Q@N
SAO-S@N
SAO-SU@N
100% of the current SV (current when the relay is OFF for the SAO-SU@N)
Fixed time at start-up and in- Instantaneous type
stantaneous thereafter
In start-up lock mode with a
600% overcurrent:
Time scale x 1: 1 to 10 s
Time scale x 4: 4 to 40 s
In instantaneous mode:
0.3 s max. at 120%
overcurrent
Approx. 30% of the current
SV
0.3 s max. with an overcur- 0.3 s max. when 120% the
rent of 120% the current SV current SV drops below
80%
Operating time charac-
Inverse type
teristics
Operating time
For a 600% overcurrent:
Time scale x 1: 1 to 10 s
Time scale x 4: 4 to 40 s
For a 200% overcurrent:
2.8 x t
±30%,
where t is
the operating time at
600% overcurrent.
(time SV at max.)
---
Initial current in start-
up mode
---
---
Inertial characteristics
Will not operate for 80% of op- ---
erating time for a 600% over-
current. (at min. current and
max. time SV)
Reset value
Operating current
accuracy
Operating time
accuracy
Influence of tempera-
ture on operating
current
More than 95% of the operating current
±10%
of the current SV
/
–5
% of maximum time SV (at a time SV: 1)
±10%
of maximum time SV (at a time SV: 2 to 10)
±5%
for 0 to 40°C;
±10%
for –10 to 50°C
+10
Less than 105% of the op-
erating current
0.3 s max.
Influence of tempera-
±10%
for 0 to 40°C;
±20%
for –10 to 50°C
ture on operating time
(start-up mode)
Influence of frequency
±3%
for a frequency fluctuation of
±5%
on operating current
Influence of frequency
±5%
for a frequency fluctuation of
±5%
on operating time
(start-up mode)
Influence of voltage on
±3%
for a voltage fluctuation of
+10
/
–15
%
operating current
Influence of voltage on
±5%
for a voltage fluctuation of
+10
/
–15
% (start-up mode)
operating time
0.3 s max. for –10 to 50°C
0.3 s max. for a frequency fluctuation of
±5%
0.3 s max. for a voltage fluctuation of
+10
/
–15
%
(start-up mode)
2
SAO
■
Characteristics (continued)
Insulation resistance
Withstand voltage
10 MΩ min. between electric circuits and the mounting panel
5 MΩ min. between contact circuits, or between contacts of same pole
2,000 VAC for 1 min between electric circuits and the mounting panel
2,000 VAC for 1 min between contact circuits and other circuits
1,000 VAC for 1 min between contacts of same pole
6,000 V max. between electric circuits and the mounting panel
4,500 V max. between contact circuits and other circuits
4,500 V max. between each control power circuits
Waveform: 1.2 x 50
µs
3 times for each poles
Motor circuit:
Continuous current:
Power supply: AC:
DC:
20 times the current SV for 2 s, applied twice with a 1 min interval
125% of the maximum current SV for each current range.
1.15 times the rated power supply voltage for 3 hrs, once
1.3 times the rated power supply voltage for 3 hrs, once
Lighting impulse withstand voltage
Overload capacity
Vibration resistance
Shock resistance
Test button operation
Ambient temperature
Ambient humidity
Altitude
Weight
Malfunction: 10 to 55 Hz, 0.3-mm double amplitude each in 3 directions for 10 min
Destruction: 10 to 25 Hz, 2-mm double amplitude each in 3 directions for 2 hrs
Malfunction: 98 m/s
2
(approx. 10G) each in 3 directions
Destruction: 294 m/s
2
(approx. 30G) each in 3 directions
Operated quickly (without lighting the LED)
Operating:
Storage:
2,000 m max.
Approx. 170 g
–10 to 60°C (with no icing)
–25 to 65°C (with no icing)
Operating: 35% to 85%
Engineering Data
■
Operating Time Characteristics
SAO-R
Time Changeover Setting: 1
Time Changeover Setting: 4
SAO-Q
Operating time (s)
320
280
240
200
160
120
80
40
Operating time (s)
500
600
Operating time (s)
80
70
60
50
40
30
20
10
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
Time scale value
10
8
6
4
2
1
Time scale value
10
8
6
4
2
1
0
100
200
300
400
500
600
0
100
200
300
400
0
100
200
300
400
500
600
Current (% of current SV)
Current (% of current SV)
Current (% of current SV)
Reset Time Characteristics
SAO-S
Operating time (s)
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
SAO-SU
Operating Time Characteristics
Operating time (s)
0.3
Operating time (s)
20
40
60
80
100
0.4
0.4
0.3
0.2
0.2
0.1
0.1
0
100
200
300
400
500
600
0
0
100
120
140
160
180
200
Current (% of current SV)
Current (% of operating current)
Current (% of operating current)
3
SAO
Installation
■
Connection
Internal Circuit
SAO-R
3-phase 50/60 Hz
R
S
T
X/C
SAO-R Current Sensor
4
5
6
Power supply
circuit
SET-3
Current Converter
Time SV circuit
Overcurrent
detecting circuit
Tap setting
circuit
Current SV
circuit
Rectifying
circuit
To all circuits
+
−
7
1
X
Output
relay
8
OC
2
Test
M
Motor
SAO-Q Current Sensor
Start-up
detecting circuit
Start-up mode
time SV circuit
OC: overcurrent LED
Note:
There is no polarity specification when using a DC power supply.
SAO-S Current Sensor
AND circuit
8
Current SV
circuit
OC
8
Current SV
circuit
7
Overcurrent
detecting circuit
7
Overcurrent
detecting circuit
OC
OC: Ovecurrent LED
OC: Ovecurrent LED
SAO-SU
3-phase 50/60 Hz
R
S
T
SAO-SU Current Sensor
4
X/C
5
6
SET-3
Current Converter
Overcurrent
detecting circuit
Tap setting
circuit
Current SV
circuit
Rectifying
circuit
To all circuits
Power supply
circuit
RY drive
circuit
7
X
Output
relay
−
8
2
NORMAL
Test
NORMAL: LED indicates operation.
(ON for a steady current,
OFF for an under current.)
M
Motor
(A)
Reset current
Operating
value
Explanation of SAO-SU Contacts
1.
The contact is NC (between terminals 4 and 5) when the motor is not started.
2.
The contact is NO (between terminals 5 and 6) when the startup pushbutton is
pressed and a current larger than the reset current flows.
3.
The contact is NC (between terminals 4 and 5) when the motor current is less than
the operating value (i.e., undercurrent).
Motor
startup
ON
Output relay
operation
Control voltage
+
1
Control voltage
RY drive
circuit
4
SAO
■
Connection Examples
Overcurrent Detection Circuit
SAO-R/SAO-Q/SAO-S
R
S
T
Undercurrent Detection Circuit
SAO-SU
R
S
T
Stop
Start
Electro-
magnetic
contactor
6
SAO
current
sensor
5
4
3
BZ
Stop
Alarm
buzzer
Start
Electro-
magnetic
contactor
6
SAO
current
sensor
7
8
1
2
5
4
3
BZ
Alarm
buzzer
Phase
advancing
capacitor
SET-3
Current
Converter
Phase
advancing
capacitor
SET-3
Current
Converter
7
8
1
2
Motor
M
Motor
M
Note:
Provide the control power supply for the SAO Current Sensor
from the contactor’s power supply side. If the control power
supply is turned ON and the motor is started at the same time,
operation inconsistent with the time SV may occur.
Note:
To prevent the buzzer sounding when power is turned ON, in-
stall a timer so that the buzzer sounds only when the timer’s
contacts are closed.
5
