Power quality – KYORITSU 6310 Instruction Manual User Manual

Page 206

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11. Power quality KEW6310

11.1

KEW6310

11. Power Quality

Power Quality

Waveform

Symptoms

Adverse effects

Harmonic

Inverter and thyristor circuits

(phase-control circuit) are used

for the control circuit of general

devices; these circuits affect

currents and causes harmonics.

Burnout of capacitors and

reactors, buzzes from trans-

formers, malfunction of circuit

beakers, flicker in screen or

noises on stereos due to

currents with harmonic

components.

Swell







Inrush currents occur when

switches for power lines are

on, and then voltages

increase instantaneously.

Dip







Inrush currents occur when

motor loads are activated, and

dip in current occurs.

Int







Power supply is interrupted

for a second due to lightning

strikes.

Shutdown of devices or

robots or reset on PC and

business machines may be

caused.

Transient,
Over-voltage
(impulse)



Contact failure at a circuit

breaker, magnet or relay.

Damage to a power source or

reset of the device may occur

due to a drastic voltage

fluctuation (spike).

Inrush current



Instantaneous large currents

(surge) flow on devices with a

motor,

incandescent lamp and

flat capacitor when powering

them on.

Influences on welded contacts

for Power switch, blowing fuse,

trip on breaker,

rectifier circuit

and fluctuations in power supply

voltage may occur.

Unbalance
rate





Heavy loading on specific phase

due to fluctuations in load of

power line or drastic extension

of installations. Distortions of

voltage / current waveforms, dip

and negative sequence voltages

are caused.

Influences on voltage, current,

motor operation occur; negative

sequence voltage and

harmonics occur.

Flicker*

Too much load is caused on

certain phases due to increase

and decrease of the loads

connected to each phase such

as supply lines or heavy use of

specific equipments, as a result,

Distortions on voltage and

current waveforms, dip and

reversed voltages are observed.

Unbalanced or reversed

voltages and harmonics occur

and result in motor unstability,

trip of 3E circuit breaker or

heating due to overload.

* Flicker measurement function is only available with ver.2.00 or later.

RMS

RMS

RMS

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