The Use Of Peripheral Equipments; Wiring Breaker; Leakage Current Breaker; Electromagnetic Contactor - Veichi AC300 Series Technical Manual

AC300 Series Vector Control Inverter Manual

7.3 The use of peripheral equipments

power
⑨
Braking resistance
Braking unit
①
Breaker
PB
P(+)
⑤
Surge restrainer
②
Leakge current
Main loop surge
breaker
absorbale unit
Winding surge
absorbable unit
③
Contactor
④
Rector
⑥
P1
Input side noise
(+)
filter
AC rector DC rector
Control sysytem standby
Chart 7-1: Peripheral equipments connetion
Note：


Wiring breaker

To ensure wiring safe, protect power system and prevent malfunction impact other equipment
working when short-circuit happens, and protect while over-load, please do use wiring breaker between power supply
and main loop power input terminals R,S,T.
While choosing the breaker, the capacitance should be about 1.5-2 times of the rated output current of
the frequency inverter. Please compare the time characteristic of breaker and the characteristic of the
inverter protection (150% of the rated output current, one minute). Make sure there will be no skip.
Before main loop wiring, make sure to cut the breaker and electromagnetic contactor.
Otherwise, there is danger of electric shock.
Peripheral Equipments and Options
Inverter
VECHI
www.veichi.com
A+
B-
S T U V W E support PC
N(-)P(+) PB R
tool(software)
R S T U V W E
Earthing
⑧
Zero-phase rector
Motor
⑦
Output side
noise filter
⑩
Earthing
Heat relay
50
AC300 Series Vector Control Inverter Manual


Leakage current breaker

The frequency inverter outputs peak voltage high-speed switch square wave, so there is high frequency leakage
current. For earth protection to prevent electric shock and leakage current fire, please install leakage current breaker.
Usually, one frequency inverter will bring 100mA leakage current (while the power cable length is 1m). If the length
prolongs 1m, there will be 5mA more leakage current. So please use leakage current breaker special for high frequency
leakage at the power input side of the frequency inverter. The factors which impact leakage current are as follows:
Capacitance of inverter;
Carrier frequency;
Motor cable type and wire length;
EMI/RFI filter.
To protect human body and inverter, please choose leakage current breaker which can use AC/DC power and can
reply high frequency leakage current. There should be one leakage current breaker with more than 200mA sensitive
current for every frequency inverter. If the frequency inverter outputs different wave, the high frequency leakage current
will be higher, what will make the breaker malfunction. At this case, please take following treatments:
Improve the sensitive current of the leakage current breaker;
Reduce the carrier frequency of the inverter.


Electromagnetic contactor

Electromagnetic contactor is a peripheral equipment what is set to separate power and inverter connection. While
inverter protective function is acting or carrying out emergency stop operation, the main loop power can be cut by
peripheral equipment. Please do not connect the electromagnetic switch or electromagnetic contactor to output circuit.
Otherwise, the inverter maybe damaged. While the power recovers after instant stop, if it needs to prevent the inverter
to auto-restart, please install electromagnetic contactor for control at the input side.
 AC input reactor and DC reactor
To restrain current sharp change and high hypo harmonic current, it needs to use AC input reactor and DC reactor. It
can also improve power factor at the input side. In the following cases, AC input reactor or DC reactor must be used
(use both will bring better effect).
Need to restrain ultra harmonics current and improve power side factor;
Need to switch input phase capacitance;
When frequency inverter is connected to large capacitance power transformer (600kVA above);
Silicon-controlled converters such as DC motor driver are connected to the same power system.
If user has higher requirement on other harmonic restraint, please connect the external DC reactor .Before
connecting the external DC reactor, make sure to dismantle the short connector between the terminals P1 and (+).
Surge restrainer

Surge restrainer is divided to winding surge restrainer and main loop surge restrainer according to the use position.
Pls choose the right one which is suitable for the occasion. The aim of surge restrainer installation is restraining the
surge voltage brought by switch components such as inductive load which is surrounding the frequency inverter
(electromagnetic contactor, electromagnetic relay, electromagnetic valve, electromagnetic winding, electromagnetic
detent). Do not connect the surge restrainer to the output side of the frequency inverter. Otherwise, the frequency
inverter will be damaged.
 Input side noise filter
Rectifier bridge of the inverter is uncontrolled rectifier. And input current is discontinuous impulse current. So the
harmonic current noise signal, what flows to power wire from the inverter inner, maybe bring bad impact on the
surrounding machines (radio, phone, noncontact switch, sensor). This time, we suggest to instal input side noise filter to
lighten the noise into the power wire. Besides, it can also reduce noise from the power wire into the frequency inverter.
Please use the special noise filter for the frequency inverter and the connection wire between the filter
Peripheral Equipments and Options
51