Mitsubishi Electric FREQROL Spécifications télécharger pdf (Page 29)

FeaturesOptions

Standard

Specifications

Parameter

List

Protective

Functions

Terminal Connection

Diagram

Terminal Specification

Explanation

Outline

Dimension

Drawings

Instructions

FR-D700 Series

Specification

Difference List

Warranty

International

FA Center

Operation panel

Parameter unit

When the inverter is run in the low acoustic noise mode, more

leakage currents occur than in the non-low acoustic noise mode

due to high-speed switching operation. Be sure to earth (ground)

the inverter and motor before use. In addition, always use the

earth (ground) terminal of the inverter to earth (ground) the

inverter. (Do not use the case and chassis)

When performing low-noise operation at higher carrier frequency,

electromagnetic noise tends to increase. Therefore, refer to the

following measure example and consider taking the measures.

Depending on the installation condition, the inverter may be

affected by noise in a non-low noise (initial) status.

z The noise level can be reduced by decreasing the carrier

frequency (Pr. 72).

z As measures against AM radio broadcasting noise, radio noise

filter FR-BIF produces an effect.

z As measures against sensor malfunction, line noise filter FR-

BSF01, FR-BLF produces an effect.

z As measures against induction noise from the power cable of

the inverter, an effect is produced by putting a distance of 30cm

(at least 10cm) or more and using a twisted pair shielded cable

as a signal cable. Do not earth (ground) shield but connect it to

signal common cable.

Capacitances exist between the inverter I/O cables, other cables

and earth and in the motor, through which a leakage current flows.

Since its value depends on the static capacitances, carrier

frequency, etc., low acoustic noise operation at the increased

carrier frequency of the inverter will increase the leakage current.

Therefore, take the following measures. Select the earth leakage

current breaker according to its rated sensitivity current,

independently of the carrier frequency setting. (Refer to page 26)

To-earth (ground) leakage currents

Line leakage current

Earth (Ground)

Noise

Inverter

Sensor

Use 4-core cable for motor

power cable and use one

cable as earth (ground) cable.

Use a twisted pair shielded cable

Inverter

power

supply

Control

power

supply

Do not earth (ground) shield but

connect it to signal common cable.

Enclosure

Decrease

carrier frequency

Motor

FR-

BSF01

FR-

BSF01

FR-

BIF

Do not earth (ground)

enclosure directly.

Do not earth (ground) control cable.

Separate inverter and power

line by more than 30cm (at

least 10cm) from sensor circuit.

Install common mode filter

on inverter output side.

FR- BLF

FR- BSF01

Install capacitor type FR-BIF filter

on inverter input side.

Install common mode filter

on inverter input side.

FR- BLF

FR- BSF01

Power

supply

for sensor

Noise reduction examples

Leakage currents

Type Influence and Measures

Influence and

measures

y Leakage currents may flow not only into the inverter's

own line but also into the other line through the earth

(ground) cable, etc. These leakage currents may

operate earth (ground) leakage circuit breakers and

earth leakage relays unnecessarily.

z Countermeasures

y If the carrier frequency setting is high, decrease the Pr.

72 PWM frequency selection setting.

Note that motor noise increases. Select Pr. 240 Soft-

PWM operation selection to make the sound inoffensive.

y By using earth leakage circuit breakers designed for

harmonic and surge suppression in the inverter's own

line and other line, operation can be performed with the

carrier frequency kept high (with low noise).

Undesirable

current path

Type Influence and Measures

Influence and

measures

• This leakage current flows via a static capacitance

between the inverter output cables.

• The external thermal relay may be operated

unnecessarily by the harmonics of the leakage current.

When the wiring length is long (50m or more) for the

400V class model, the external thermal relay is likely to

operate unnecessarily because the ratio of the leakage

current to the rated motor current increases.

z Countermeasures

• Use Pr.9 Electronic thermal O/L relay.

• If the carrier frequency setting is high, decrease the Pr.

72 PWM frequency selection setting.

Note that motor noise increases. Select Pr. 240 Soft-PWM

operation selection to make the sound inoffensive.

To ensure that the motor is protected against line-to-

line leakage currents, it is recommended to use a

temperature sensor to directly detect motor

temperature.

Undesirable

current path

Power

supply

Leakage

breaker

Leakage

breaker

NV1

NV2

Inverter

Motor

Power

supply

Thermal relay

Line-to-line static

capacitances

MCCB MC

Line-to-line leakage currents path

Motor

Inverter

1 2 ... 24 25 26 27 28 29 30 31 32 33 34

Commentaires sur ces manuels

Pas de commentaire

Mitsubishi Electric FREQROL Spécifications Page 29

Commentaires sur ces manuels

Produits connexes et manuels pour Tournevis électriques Mitsubishi Electric FREQROL