K8AB-PH 查看數據表（PDF） - OMRON Corporation

零件编号

产品描述 (功能)

比赛名单

K8AB-PH

Phase-sequence Phase-loss Relay

OMRON Corporation 

Questions and Answers

Q Checking Operation

Phase Sequence

Switch the wiring, as shown by the dotted lines in the

connection diagram, to reverse the phase sequence and

check that the K8AB operates.

Phase Loss

Create a phase loss for any input phase and check that the

K8AB operates.

Connection Diagram

3φ,

200 VAC

L1

L1

L2

L2

L3

L3

Q Can phase loss be detected on the load side?

In principle, phase loss cannot be detected on the load side

because the K8AB-PH1 measures three-phase voltage to

determine phase loss.

K8AB-PH

Q Motor Load Phase Loss during Operation

Motor load phase loss cannot be detected during operation.

It can be used to detect phase loss at startup.

Normally, three-phase motors will continue to rotate even if

one phase is open. The three-phase voltage will be induced

at the motor terminals. The diagram shows voltage induction

at the motor terminals when phase R has been lost with a

load applied to a three-phase motor. The horizontal axis

shows the motor load as a percentage of the rated load, and

the vertical axis shows voltage as a percentage of the rated

voltage. The lines in the graph show the voltage induced at

the motor terminals for each load when phase loss occurs

during operation. As the graph shows, voltage is induced at

the motor terminals even if there is phase loss for a motor

load, so the K8AB-PH1 cannot detect phase loss for motor

loads during operation. Use the K8AB-PH1 to detect phase

loss at startup.

Characteristic Curve Diagram

Note: This characteristic curve shows the approximate

values only.

100

95

90

VST

85

80

VTR

75

70

65

60

55

50

45

VRS

0 10 20 30 40 50 60 70 80 90 100 110

Motor load (as a percentage of rated load)

Note: For phase loss of phase R. VST, VTR, and VRS indicate the motor

terminal voltage at phase loss.

ALL DIMENSIONS SHOWN ARE IN MILLIMETERS.

To convert millimeters into inches, multiply by 0.03937. To convert grams into ounces, multiply by 0.03527.

In the interest of product improvement, specifications are subject to change without notice.

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