Fulling DZB200M

To Next Page

To Previous Page

2) Reducingthe disturbance to thein verter fro m otherequipment

The relay, cont actor or electronic -magnetic braking device will disturb the inverter.

Tak et h e f oll owi ng a ctions to sol ve this issu e:

A) Insta ll s urge sup pres sing devi ces toth e disturb ing de vic e

B) Install filter to theinputof the inverter

C) Inverter's contro l cables shall be s hielde d a ndthe shie lding la yer shall be gro un ded

3) Met hod to r ed u ce thedi stu rbance f rom th einverte r to the eq uip ment

Two k inds of nois es , one i s the ra dia t ion f rom the inv erter itself, an da nother is the rad iatio n f rom th e

cable betwee n th einve rter and th e moto r.These tw okinds o f ra diat ion s in d u ce t he cab le s of t he

equ ipment and m ake the equipment worka bno rmally.Fo llowingm ethod can be used:

A) Ifthe measuring me ters, ra dio equipment and sensors a nd th eir signal cab l es are install ed in a

cabinet together with the drive, these equip ment cables will be eas ilydisturb ed. Take theactions

below to solvethe problem: The equipment and the signal cables shouldbe as far away from the

invert e r as possible; Signal cable s and p ower cables shall not b e route d in parallelo r boundtog et he r;

The si gnal and p owe r cable s s h ould b e shielde d; I nst a ll radio noise filter and linear no ise filt er a t

the inp ut a nd o ut put side s of t h e inve rte r

B) Ifthe e xternal eq u ipme nt s hares a sam eAC supply witht he inver ter, a nd the abo v e cannot eliminate

the dis turban ce, the n the user sho u ld inst al l a l ine ar fil te r or a r adio no ise filter.

C) Ground th e ext ernal equipment and e lim ina te t h e dist urb ance of thelea kage cur ren t fro mthe

inverter's groundingcable.

The inverter has tw o kinds of le akag e curre nt, one i s the gro unding lea k age curre nt a nd anoth er i s th e

lea kage current betw een the lines:

1) Grou nding leakage c urr ent:

The distributed capacitance exists between the cables an d the ground,andthe biggerthe capacitance

and the bigger the leakage current, so the m otor cables should be as short as possi ble. Besides, the

bigger the carrier frequenc y is, the bigger theleakage cu rrent is, sothe user can also reduc e the carr ier

wave frequency, but the motor noise mayincre ase . Installing reactor can also reduce theleakage current.

The le akage c ur rent is incre ased wit h th e incre ase of the circ uit current, so th e l eakage current is big if

the motor power is b ig .

2) Lea kage current betweenli nes:

The distributed capacitance exists in the inver ter抯 output cables,

and re son anc em ay occur if hi gh

frequency har mo nicse xist in t he current, th us the lea kagecurrent occurs, which m ayresult in t he wrong

action ofrela y.

The meth od to sol ve this is sue i s to redu ce the car rier f re quency or install the ou tput react or.It is

rec om m e nded to us e inv erter抯 p rotection fun ctioni nst ead of a thermal r elayto protect t hemotorbefore

using the inverter.

6.3 Leakagecurrent

-15- -16-

Note: Pa y atten tion to the p olarit y of t he dio de as sh own in the f igur e 3-8 . O the rwise i f the digita l

output terminal has output, the DC24V power supply will be damaged.

6. EMC I ssues

61InfluenceofHarmonics

6. 2EMI

1) The highfr equen cy harmoni cs o f mains supply will influe nce th e rect ifying circu it oft he inv e rter.

Th e harmonics will heatt herectifying circuit an d ev en dama geth e circuit.So, itis recommendedt o

install the fi ltering device in the en vironment where the power quality is poor.

Since theinverter output has high freque ncy h ar monics, the o ut put cannot b e ins talled with

ca pacitor or su rges uppress ing devic es bec ause the cap acito r ands urge suppre ssing devic e may

resonate t hec ircu it and d amage the equipm ent .

1) Two k inds of EMI, one is the EMI ar ound the i nvert er and di sturbsthe inve rt er. Thiski n dof E MI is

w eak, b esides the inverter has be ende signed with stro n g im munity.Anot her is the E MI f rom the

inve rter that may in f luence the equipment a roun d the inv erte r. The inver ter itself is a dist ur banc e

so urce becaus e it ou tpu ts PWM wa ve t hrough high car rier f re quency,so s olving the EMI issue is

ma inly to reduce t h e EMI ofinv erter.

Methods:

A ) Inverte r an d other equip ment shall be w ell grou nde d and thegrounding res istanc e shall be le s s tha n

5ohm.

B ) Inve r ter's p ower cable s shall b eve rtical inste ad of parallel with the c ontro l cables.

C) For theapp lication with strong disturbance, the power cables fromthe motor tothe inverter shallb e

sh ielded and the shi elding laye r s hall be grounded.

D ) T hec ables of dis turbed equi pment shall be t w isted s hie lde d ca bl es andthe shielding la yer shall be

gr ounde d.

DZB300

MO1

MCM

Relay

Di ode

Fig. 3 -8Digital Input Terminal of DZB Ser ies Inverter

Cha pt er 3 Mechanic al and Electrical In stalla tio n

DZB Series

Chapte r 3 Mechanic al and E lectrical In stallation

DZB Series

BLUE ELEPHANT

Main Page

Fulling DZB200M - Page 11

Table of Contents