A complete RNMZ includes power module, control module, thyristor module, motor protection module, communication module and so on.
The control core of RNMZ series product is microprocessor (CPU), which starts and protects the motor.
CPU controls the SCR to conduct phase angle trigger control, lowering the voltage on motor, then controls the voltage on motor and increases the motor torque of the smooth current until motor runs in full speed. The above way of starting can lower the inrush current of motor, reducing the impact on power grid and motor itself. Meanwhile, it also reduces the mechanical impacts on motor loading device, prolonging device service life and reducing motor breakdown.
○ Structure: the device adopts an integrated design of power unit and control unit, a perfect match with handcart circuit breaker in operation way, is small in size and equipped with a unique locking mechanism. The cabinet body of HV KYN28 is ready for use by connecting the three phase input copper row, three phase output copper row and bypass contactor. And the part of soft starting device is an independent module, is easy for installation and use by adopting the heavy load linker in secondary control lines.
(1)Drive power supply: it adopts a current type high-frequency power supply -- this power supply has various protection functions, stable output voltage, small ripple, high isolation voltage and other features.
(2)Trigger unit: it adopts the thyristor high-frequency trigger power unit developed by our company, which keeps high consistency in conduction time of each thyristor, improves device stability and reduces failure rate of the thyristor.
○ Sampling: the electronic sampling method (EVT and ECT) is adopted for both voltage and current sampling, which replaces the high voltage transformer, avoids the over-voltage harm caused by the resonance of the voltage transformer (PT), and realizes the photoelectric isolation.
○ Performance: due to the change of power component structure, the motor starts more smoothly, reducing the harmonic quantity and causing lesser the interference to the power grid.
○ Protection: both overvoltage protection with thyristor in series and circuit with capacitance-resistance absorption, adopt the double dv/dt principle, causing a better absorption of the instantaneous voltage.
○ Reliability: the trigger mode of the driving power supply and power unit has been changed. The main circuit and the control circuit are completely isolated by optical fiber, which avoids not only the electromagnetic interference of the strong electric part, but also the damage caused by the breakdown of the high voltage to the low voltage part, lowers the failure points and increases the reliability.
○ Test and maintenance: the change of a power component structure makes the component lighter, more simple, easier for test and maintenance.
RNMZ handcart series MV/ HV solid soft starter is widely used in the squirrel-cage AC asynchronous and synchronous motors of power system, machinery manufacturing, cement production, metallurgy, mining, oil extraction, chemical industry, water treatment and others. It is used for MV/ HV motor start, control, protect and soft-stop as three phase voltage of 3KV~10KV.
● Load type: Three-phased squirrel-cage AC asynchronous and synchronous motors
● AC voltage: 3kV, 3.3kV, 6kV, 6.6kV, 10kV AC-15%~+10%
● Insulation voltage: Line voltage: 3000V, 6000V, 10000V; Insulation voltage: 18000V, 25000V, 42000V
● Overload capacity: Continuity: 125% of controller nominal value; Overload: 500% 60 Seconds
● Frequency: 50Hz/60Hz±2Hz Auto choice
● Main circuit Components: (12 SCRS, 18SCRS OR 30SCRS Depends on the models)
● SCR Peak reverse voltage: 13000V~32500V(Decided by model)
● Phase sequence: RNMV is allowed to operate under any phase and sequence
● Instantaneous overvoltage protection: dv/dt Absorb network
● Cooling: Natural cooling
● Bypass: It has the bypass vacuum contactor which can directly start capacity. When the rated current is over 450A, fixed vacuum circuit breaker shall be adopted.
● Ambient Conditions: Cabinet temperature: 0℃~50℃(32℃-122℃); Base temperature 0℃-50℃, (-20℃-50℃ an option of a heater); Altitude of no more than 2000 meters, a relative humidity of 5%-95%; reduced capacity shall be adopted for the altitude of over 2000 meters.
● Control way: The user provides 2 or 3 line of 220 VAC or 220VDC, 1000VA.
● Auxiliary relay: C-type dry relay, 5-10A 250V, one programmable interlock relay, one bypass relay, one fault output; Relay
● Current: Two-phase timing, inverse-time limit over-current protection (limiting time quick-acting relay, limited to Type G, over-current); Two-phase negative sequence timing, inverse-time over-current protection (negative sequence limiting time quick-acting relay, limited to Type G, negative sequence over-current)
● Overload: Motor shaft lock protection & Overload alarm
● Temperature: Protection from the temperature relay (Over temperature & temperature rise)
Protection for soft-start
● Temperature: Protection for the SCR components; it shall trip when the temperature is higher than 85℃.
● Protection for over-time starting: It shall trip when the starting time is more than 120 seconds.
● Input Phase Loss: Any one loss in the three-phase power shall cause motor failure and alarm.
● Starting times in an hour: No than 6 times of starting in an hour; minimum starting interval: 5 minutes.
Product model description:
Model Selection Table：