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13

K2CM

Voltage Reverse-phase Detection Models

The operating characteristics listed in the table below are tested
using the circuit shown on the right. Decide the number of conductor
passes through the holes of the current transformer in accordance
with the operating current range of the Motor Protective Relay and by
referring to the current setting method described under 

Operation,

Setting, and Indication

.

* Balance the currents between phases by adjusting variable resistor R1.

** If a current equal to 600% of the set current value cannot be attained by adjusting the voltage regulator, increase the number of conductor passes

through the holes of the current transformer.

Test item

Test procedure

Operating value

Operating time

Over-
current

Inverse type

1.

Turn ON SW1.

2.

Turn ON SW2 to operate auxiliary relay Y.

3.

Gradually increase the current by adjusting the voltage
regulator. With inverse-type models, read the value of the
current when the overcurrent LED indicator blinks. With
instantaneous-type models, read the value when it lights
(continuously).*

4.

Turn OFF SW1 and SW2.

1.

Turn ON SW1 and SW2. Increase the current by adjusting
the voltage regulator to 600% of the set current value.
Turn OFF SW1 and SW2.**

2.

Turn ON SW1.

3.

Turn ON SW2 and read the position (i.e., time) of the
pointer of cycle counter CC when CC is stopped by the
operation of the K2CM. The read time is the operating time
for inverse-type models and the lock time of the instanta-
neous-type models.

4.

Turn OFF the SW1 and SW2.

Instantaneous 
type

1.

Turn ON SW1 and SW2. Increase the current to 100% of
the set current value by adjusting the voltage regulator.
Then turn OFF SW1 and SW2.

2.

Turn ON SW1 and SW2 again and wait 2 seconds mini-
mum.

3.

Using the voltage regulator, abruptly increase the current
to 140% of the set current value. Confirm that the K2CM
performs the instantaneous operation.

4.

Turn OFF SW1 and SW2.

Open-phase

1.

Open (disconnect) any one of the input phases for the cur-
rent transformer.

2.

Turn ON SW1 and SW2. Gradually increase the current by
adjusting the voltage regulator.

3.

Confirm that the K2CM operates at a current no greater
than 85% of the set current value and that, at this current,
the trip indicator is orange and the open-phase LED indica-
tor lights.

4.

Turn OFF SW1 and SW2.

1.

Open (disconnect) any one of the input phases for the cur-
rent transformer.

2.

Turn ON SW1 and SW2. Increase the currents of the other
two phases to 115% of the set current value by adjusting
the voltage regulator. Turn OFF SW1 and SW2 temporarily.

3.

Turn ON SW1 and SW2 again. Read the position (i.e.,
time) of the pointer of cycle counter CC when CC is
stopped by the operation of the K2CM.

4.

Turn OFF SW1 and SW2.

Reverse-phase

1.

Change the phase sequence to reverse-phase by switch-
ing the U and W input terminals of the K2CM as shown by
the dotted lines.

2.

Turn ON SW1 and SW2 and confirm that the K2CM oper-
ates.

3.

Add a three-phase voltage regulator to the U, V, and W ter-
minal inputs.

4.

Adjust the voltage regulator and confirm that the K2CM
operates at less than 80% of the rated supply voltage.

1.

Put the voltage input in the reverse-phase state.

2.

Turn ON SW1 and SW2 and read the position of the
pointer of cycle counter CC when CC is stopped.

3.

Turn OFF SW2.

R

1

R

1

T

a

T

c

T

b

U

V

W

K2CM Motor Protecti

v

e Relay

R

2

3

φ

SD: Three-phase 

v

oltage reg

u

lator (5 to 15 A)

A: 

AC ammeter (5 A)

V

: AC 

v

oltmeter (300 

V

)

CC: Cycle 

co

u

nter

Y: A

u

xiliary relay (15 A)

R1: 

V

aria

b

le resistor (50 

Ω

, 400 

W

 + 400 

W

)

R

2

: Fixed 

resistor 

(50 

Ω

, 400 

W

 + 400 

W

)

S

W

1

: Knife s

w

itch (3-phase)

S

W

2

: Toggle s

w

itch

Y

U

V

W

200 

V

50/60 Hz

(3-phase)

100 

V

AC

50/60 Hz

S

W

1

S

W

2

CC

3

φ

SD

100 

V

C

±

Minim

u

m set time is 2 s.

Summary of Contents for K2CM Series

Page 1: ...ng the K2CM Model Number Structure Model Number Legend 1 Model K2CM Motor relay 2 Mounting style None Surface mounting integrated type 3 Operating time characteristics None Inverse type Q Instantaneou...

Page 2: ...AC 2 A 440 VAC 1 A 110 VDC 0 2 A 220 VDC 0 1 A Contact form of output contact Current reverse phase detection models SPST NO SPST NC Voltage reverse phase detection models SPDT Operating current range...

Page 3: ...Current reverse phase detection models 6 000 V between current carrying terminals and mounting panel 4 500 V between current carrying terminals and between control power supply terminals Waveform 1 2...

Page 4: ...Manual Operation High voltage Circuit Note Connect the phase advancing capacitor on the power supply side of the Motor Protective Relay as shown in the above dia grams Ta Tc Tb U V W Output contacts...

Page 5: ...t High capacity Motor Automatic Operation Low voltage Circuit Manual Operation High voltage Circuit S1 C2 b2 a1 c1 S2 Output contacts NO and NC Control power supply R S T BZ R U A 1 S V B 2 T W C 3 a1...

Page 6: ...ens of seconds to settle to the rated current This time varies largely depending on type of motor and the nature of motor load wt There fore it is necessary to obtain the motor s starting time for ope...

Page 7: ...required for the detection of inter nal open phases in delta connected motors Consult your OMRON representative before using this method When a transformer is con nected as a load the harmonics increa...

Page 8: ...n is released after the motor circuit has tripped the circuit remains tripped whereas with automatic resetting models the motor circuit continues operating and the output relay releases Deciding the N...

Page 9: ...is made at the load side far from the current transformer and the motor rotates in the re verse direction the K2CM does not detect the reverse phase Reverse detectable Range The OR phase circuit in th...

Page 10: ...aracteristics for Inverse Type Overload Operating Time Characteristics for Instantaneous Type 2 0 1 0 0 100 200 300 400 500 600 700 This graph shows the behavior when the current changes from 100 of t...

Page 11: ...ive motor full load characteristics of 200 VAC 4 pole totally enclosed Note When using a large capacity or high voltage motor whose capacity is 45 kW or more calculate the rated current alternating cu...

Page 12: ...the input phases for the cur rent transformer 2 Turn ON SW1 and SW2 Gradually increase the current by adjusting the voltage regulator 3 Confirm that the K2CM operates at a current no greater than 85 o...

Page 13: ...3 Using the voltage regulator abruptly increase the current to 140 of the set current value Confirm that the K2CM performs the instantaneous operation 4 Turn OFF SW1 and SW2 Open phase 1 Open disconn...

Page 14: ...ection of a high voltage motor or low voltage high capacity motor use an external rectifier that does not saturate at currents up to 600 of the rated motor current and thus permits a large overcurrent...

Page 15: ...ase with the K2CM Connection Method Pass wires through any two of the three holes on the K2CM If a single phase is used set the open phase and reverse phase switch to OFF Make the overload settings so...

Page 16: ...ther in no event shall liability of Omron Companies exceed the individual price of the Product on which liability is asserted Suitability of Use Omron Companies shall not be responsible for conformity...

Page 17: ...2CM 1LA K2CM 1LS K2CM 1M K2CM 1MA K2CM 2H K2CM 2HA K2CM 2L K2CM 2LA K2CM 2LS K2CM 2M K2CM 2MA K2CM 4H K2CM 4HA K2CM 4L K2CM 4LA K2CM 4M K2CM 4MA K2CM Q1H K2CM Q1HA K2CM Q1L K2CM Q1LA K2CM Q1LS K2CM Q1...

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