Monitoring Relays
3-Phase Load Guard
Types DWA01, PWA01
• Cos
ϕ
monitoring relays
• Measuring if power factor is within set limits
• Measure on own power supply (voltage) and current
for balanced systems
• Measuring ranges for current: 5A and MI current
transformers range
• Power ON delay 1, 2 or 6 s selectable
• Knob adjustable level on absolute scale
• Output: 8 A SPDT relay Normally Energized
• For mounting on DIN-rail in accordance with DIN/EN
50 022 (DWA01) or plug-in module (PWA01)
• 22.5 mm Euronorm housing (DWA01) or 36 mm
plug-in module (PWA01)
• LED indication for power supply and output ON
DWA01
PWA01
Product Description
DWA01 and PWA01 are pre-
cise over or under cos
ϕ
monitoring relays.
The relays monitor their own
power supply voltage and
the current of a balanced 3-
phase system.
For current measure direct
connection, 5A standard cur-
rent transformers and MI CT
can be used.
The LED's indicate the state
of the alarm and the output
relay.
Ordering key
Housing
Function
Type
Item number
Output
Power Supply
Range
DWA 01 C M48 5A
Type Selection
Mounting
DIN-rail
Plug-in
Output
SPDT
SPDT
Supply: 208 to 240 VAC
DWA 01 C M23 5A
PWA 01 C M23 5A
Supply: 380 to 415 VAC
PWA 01 C M48 5A
Supply: 380 to 480 VAC
DWA 01 C M48 5A
Input Specifications
Input
Voltage (Own power supply):
3 - phase
DWA01:
PWA01:
M23:
DWA01CM48:
PWA01CM48:
1- phase DWA01CM235A:
PWA01CM235A:
Current
DWA01:
PWA01:
Measuring ranges
Power factor (cos
ϕ)
Direct input
Standard CT (examples)
TADK 2 50 A/5 A
TAD 2 150 A/5 A
TAD 6 400 A/5 A
TAD 12 1000 A/5 A
TACO 200 6000 A/5 A
MI CT ranges
MI 100
MI 500
Level
0.1 to 0.99
AACrms
0.5 to 5 A
5 to 50 A
15 to 150 A
40 to 400 A
100 to 1000 A
600 to 6000 A
AAC rms
10 to 100 A
50 to 500 A
Max. curr.
30A 30s
60 A
180 A
480 A
1200 A
7200 A
Max. curr.
250 AAC
750 AAC
L1, L2, L3
5, 6, 7
208 to 240 VAC ± 15%
380 to 480 VAC ± 15%
380 to 415 VAC ± 15%
L1, L3
5, 7
208 to 240 VAC ± 15%
5A: Y1, Y2
MI CT: Y1, Y3
5A: 7, 5
MI CT: 7, 6
Note:
The input voltage cannot
raise over 300 VAC with
respect to ground (PWA01
only).
Hysteresis
~ cos
ϕ
= 0,02 - fixed
Output Specifications
Output
Rated insulation voltage
Contact ratings
(AgSnO
2
)
Resistive loads
AC 1
DC 12
Small inductive loads AC 15
DC 13
Mechanical life
Electrical life
SPDT relay
250 VAC
µ
8 A @ 250 VAC
5 A @ 24 VDC
2.5 A @ 250 VAC
2.5 A @ 24 VDC
≥
30 x 10
6
operations
≥
10
5
operations
(at 8 A, 250 V, cos
ϕ
= 1)
≤
7200 operations/h
Operating frequency
Dielectric strength
Dielectric voltage
≥
2 kVAC (rms)
Rated impulse withstand volt. 4 kV (1.2/50 µs)
Specifications are subject to change without notice (09.12.05)
1
DWA01, PWA01
Supply Specifications
Power supply
Rated operational voltage
through terminals:
DWA01:
PWA01:
M23
DWA01CM48
PWA01CM48
Dielectric voltage
supply to output
Rated operational power
Supplied by
Overvoltage cat. III
(IEC 60664, IEC 60038)
L1, L2, L3
5, 6, 7
177 to 276 VAC 45 to 65 Hz
323 to 552 VAC 45 to 65 Hz
323 to 477 VAC 45 to 65 Hz
None
2kV
13 VA @400VAC
L1 and L3
General Specifications
Power ON delay
Reaction time
Alarm ON delay
Alarm OFF delay
Accuracy
Temperature drift
Repeatability
Indication for
Power supply ON
Output ON
Environment
Degree of protection
Pollution degree
Operating temperature
@ Max. voltage, 50 Hz
@ Max. voltage, 60 Hz
Storage temperature
Housing dimensions
DIN-rail version
Plug-in version
Weight
Screw terminals
Tightening torque
Approvals
CE-Marking
EMC
Immunity
Emission
1, 2, or 6 s ± 0.5 s
(input signal variation from
-20% to +20% or from
+20% to -20% of set value)
< 400 ms
< 400 ms
(15 min warm-up time)
± 1000 ppm/°C
± 0.5% on full-scale
LED, green
LED, yellow
IP 20
3 (DWA01), 2 (PWA01)
-20 to 60°C, R.H. < 95%
-20 to 50°C, R.H. < 95%
-30 to 80°C, R.H. < 95%
22.5 x 80 x 99.5 mm
36 x 80 x 94 mm
Approx. 200 g
Max. 0.5 Nm
acc. to IEC 60947
UL, CSA
Yes
Electromagnetic Compatibility
According to EN 61000-6-2
According to EN 61000-6-3
Function/Delay/Level Settings
Level setting (cos
ϕ
):
Knob adjustable on absolute
scale, from 0.1 to 0.99
Setting of function and
power ON delay
Adjust the desired function
(over or underload monitor-
ing) with DIP switch 1 and
the power ON delay with
DIP Switches 3 and 4 as
shown on the below table.
To access the DIP-switch
open the plastic cover using
a screwdriver as shown on
the left.
Monitoring function
ON: Under cos
ϕ
OFF: Over cos
ϕ
Not used
Power ON delay
SW3 SW4
OFF OFF: 6 sec
ON OFF: 2 sec
ON ON: 1 sec
Mode of Operation
DWA01 and PWA01 can be
used for monitoring the
actual load of asynchronous
motors.
The relays measure the 3-
phase supply voltage and
the current of the phase L1
connected to an asyn-
chronous motor.
The relay monitor the cosine
of the angle between motor
current and motor voltage
(cos
ϕ).
As cos
ϕ
varies with the load
of the motor, overload (or
underload) can be indirectly
detected by DWA01 and
PWA01.
The relation between the
load and cos
ϕ
depends on
the type of motor.
As a guideline to ensure cor-
rect working conditions for a
motor, the level could be set
above (or below) the cos
ϕ
marking on the motor. It is
however recommended to
make the adjustment in con-
nection with a practical test.
The relay has an inhibit
delay at power ON in order
to avoid overload detection
during motor start.
Example 1:
Overload monitoring.
The relay operates and the
yellow LED is ON as long as
cos
ϕ
is below the set limit.
The relay releases when it
exceeds the set level.
Example 2:
Underload monitoring.
The relay operates and the
yellow LED is ON as long as
cos
ϕ
is above the set limit.
The relay releases when it
drops below the set level.
Example 3:
DWA01CM235A
and
PWA01CM235A can be used
for monitoring the cos
ϕ
of a
1-Phase load with 208 to 240
V AC mains voltgage. In this
case the power supply has to
be connected between L1, L3
(or 5, 7) and L2 and L3 (or 6
and 7) have to be connected.
2
Specifications are subject to change without notice (09.12.05)
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