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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 drive. Please compare the
time characteristic of breaker and the characteristic of the drive 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.Leakage current breaker
The frequency drive 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 drive 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 drive. The factors which impact leakage current are as follows:
Capacitance of drive;
Carrier frequency;
Motor cable type and wire length;
EMI/RFI filter.
To protect human body and drive, 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 drive. If the frequency drive 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 drive.
Electromagnetic contactor
Electromagnetic contactor is a peripheral equipment what is set to separate power and drive connection. While drive 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 drive maybe damaged. While the power recovers after instant stop, if it needs to prevent the
drive 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 drive 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 drive (electromagnetic contactor, electromagnetic relay, electromagnetic valve, electromagnetic winding,
electromagnetic detent). Do not connect the surge restrainer to the output side of the frequency drive. Otherwise, the frequency drive will be damaged.
Input side noise filter
Rectifier bridge of the drive is uncontrolled rectifier. And input current is discontinuous impulse current. So the harmonic current noise signal, what flows to
power wire from the drive 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 drive.
:Please use the special noise filter for the frequency drive and the connection wire between the filter and the drive should be as short as possible.
Output side noise filter
The frequency drive outputs square wave with high-speed peak value voltage switch. So there is high-speed dv/dt conver on the output cables that will
produce a large number of radio disturbance and inductive signal. By installation noise filter at the output side, the impact can be relieved. Please do not
install the into phase capacitance and the noise filter to the output circuit. Otherwise, there is danger of damage to the frequency drive.
Phase reactor
0-phase reactor is used for reducing the electromagnetic interference of the frequency drive, which is suitable for the input side and output side. It equals
to a three-phase common mode inductance. In actual use, according to the actual magnetic core size and cable specification, it is better to make sure 3-
5 circles winding ratio to bring the best performance.
Braking reactor or braking unit
Renewable electricity consumption unit, please see the sixth part of the chapter three "electric installation".
Heat relay
Please install the heat relay at the output side of the frequency drive. When the motor enters into overload state, it will cut the power source to protect the
motor. While using one frequency drive to drive one motor, it is unnecessary to install heat relay. The motor overload protection current [F10.16] of the
frequency will work. While using one frequency drive to drive multiple motors or the motor is drove directly by the power grid, please install heat relay
between the drive and the motor. While installing the heat relay, please design to cut the sequence control circuit of the MC at the main loop iuput side by
the connection spot of the relay or design to input the heat relay action into the frequency drive as the exterior malfunction. And please pay attention to the
following tips to avoid heat relay malfunction and motor overheating at low speed.
Run at low speed
One frequency drive run multiple motors
Motor cable is very long
Detect malfunction mistakenly for carrier frequency is too higher.
Low speed and heat relay
In normal case, the heat relay is suitable for the universal motor. While using the frequency drive to run the universal motor (standard motor), the motor
current is 5-10% higher, comparing with the commercial power supply. Besides, at low speed, even in the motor rated current range, the cooling capability
57
Peripheral Equipments and Options
AC10 Series Frequency Inverter Technical Manual
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