Selection of motor protectors
<br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br> Overload protector, intelligent motor protector, microcomputer motor protector, motor integrated protector, power supply protection relay, surge protector, thermostat, explosion-proof switch, explosion-proof control box, escalator synchronization rate tester, independent automobile air conditioner Controllers, automotive wind turbine stepless speed regulators, boiler level gauges, etc., for the domestic major elevator plants, thermal power plants, auto factories and other supporting.
Motor motor air compressor (hereinafter referred to as air compressor) fault can be divided into motor failure and mechanical failure (including crankshaft, connecting rod, piston, valve plate, cylinder head gasket, etc.). Mechanical failures often overload the motor or even stall it, which is one of the main causes of motor damage.
Damage to the motor is mainly manifested in damage (short circuit) and disconnection of the stator winding insulation. It is difficult to find the stator winding after it is damaged, and it may eventually cause the winding to burn out. After the winding is burned, some phenomena or direct causes of burn-out are obscured, making post-analysis and cause investigation difficult.
However, the operation of the motor is inseparable from the normal power input, reasonable motor load, good heat dissipation and protection of the winding enameled wire insulation layer. First, the conditions
<br> <br> motor protection selection and selection related to
the existence of both motor and protector equipped with how reasonable relationship, here are a few protection-related conditions, factors, when the user selection for reference.
1. Motor: We must first understand the model specifications, motor functional characteristics, protection type, rated voltage, rated current, rated power, power frequency, insulation level and so on. These contents can basically provide reference for the user how to correctly use and maintain and select protectors.
2. Environmental conditions: Mainly refers to normal temperature, high temperature, cold, corrosion, vibration, sand, altitude, and electromagnetic pollution.
3, the use of motor: mainly refers to the characteristics of the requirements of mechanical equipment, such as fans, pumps, air compressors, lathes, oil field pumping units and other mechanical characteristics of the load.
4. Control system: The control modes include manual, automatic, local control, remote control, independent stand-alone operation, and centralized production line control. The starting methods include direct, step-down, star-delta, frequency-sensitive rheostat, frequency converter, and soft start.
5. Other aspects: The user's management of on-site production monitoring is more casual or rigorous, and the severity of non-normal downtime impact on production.
Product Features This product is a kind of intelligent power protection device, using a microcontroller and digital processing technology, set voltage display, over voltage protection, phase loss protection, phase sequence protection and timing meter functions in one, Chinese liquid crystal display, It is characterized by easy operation, compact size and high reliability.
Scope This product can be widely used in a variety of low-voltage electrical control system, replacing the traditional phase sequence relay and over-voltage protection. two. The main technical parameters DFY-5
Voltage display over-voltage protection phase loss protection phase sequence protection timekeeping and metering fault recording sound and light alarm 1. Power supply voltage: three-phase 280V ~ 450VAC2. Voltage measurement accuracy: Â± 1% 3. Output contact capacity: 2A/250VAC4. Working environment: Temperature -10C ~ 50C Humidity 85%, no condensation 5. Frequency: 50/60HZ6. Dimensions: (length * width * height): 48*48*90mm Third, the operation guide
1. Display function In the normal display, the LCD display shows the current power supply voltage value (AB phase voltage)
2. Alarm function When power supply over-voltage, phase loss, fault and other faults occur, the LCD flashes â€œovervoltageâ€, â€œundervoltageâ€, â€œphase lossâ€, â€œphase errorâ€, etc., relay output contacts. disconnect. The DFY-5 emits audible and visual alarms at the same time. Press any key to eliminate the alarm tone and fault time.
3. Set the under-voltage value Press and hold the â€œSelâ€ button for 2 seconds. The â€œSettingâ€ and â€œOvervoltageâ€ are displayed on the LCD. Then use the â€œâ€ button to change the overvoltage setting value (the â€œâ€ button is increased by 1V. , "" button minus 1V, press and hold for more than 0.5 seconds then quickly increase or decrease). Press the â€œSelâ€ button again to set the under voltage value in the same way. Press the â€œSelâ€ button to exit the setting state. (Note: Over and under pressure can also be set with internal parameters F11 and F12. The effect is the same).
When the over-voltage value is set to the maximum, â€œOFFâ€ is displayed, indicating that the over-voltage alarm function is turned off; when the under-voltage value is set to the minimum, â€œOFFâ€ is displayed, indicating that the under-voltage alarm function is turned off.
4. Internal parameter setting In the display voltage state, press and hold the â€œâ€ button for 5 seconds to enter the parameter setting status. At this time, â€œFxxâ€ is displayed on the display, where xx is a two-digit number indicating the parameter code. Use "" or "" key to select the parameter code, press "Sel" key to display the corresponding parameter value of the parameter code, then use "" or "" key to set the parameter value, and then press "Sel" key, back to display parameter code status.
The internal parameter code is shown in the following table:
Category Code Parameter Name Setting Range Factory Setting Unit Remarks Voltage Setting Type F11 Over Voltage Setting Value 200-500
OFF437V generates an alarm when the voltage is â‰¥ 437V, and recovers when the voltage is â‰¤ 435V. When the voltage is less than or equal to 304V, an undervoltage alarm is generated, and when the voltage is greater than or equal to 306V, the alarm is restored. "OFF" indicates that the overvoltage or undervoltage alarm function is turned off.
F12 under voltage setting OFF
F13 over voltage recovery differential 1-202V
Operating time F21 Over-voltage operating time 0.1-205.0 seconds Various types of faults need to be set for a period of time to have an effect. Off-phase or wrong phase action time setting "OFF" means that the phase-missing or phase-out alarm function is disabled.
F22 missing action time 0.1-20
OFF3.0 seconds F23 out of phase action time 0.1-20
OFF2.0 seconds F98 shows the phase difference between the CA phase and the AB phase. When the normal phase sequence is displayed, it shows about 240 degrees, the wrong phase shows about 120 degrees, and the missing phase shows 0.
END exit settings Fourth, the wiring diagram
<br> <br> wiring diagram Note:
1. The relay output is closed when the instrument is working properly, and the instrument is de-energized or the fault protection status is disconnected.
2. The AB phase is the working power supply of the instrument. The voltage and over-voltage and under-voltage protection shown when the instrument is working are all based on the AB phase voltage. If phase A or phase B is missing, the meter is not displayed and the relay output is disconnected.
3, DFY-6 count signal for the voltage signal, can adapt to 80 ~ 450V wide voltage range (if you need other voltage specifications can be customized), AC and DC can be, if it is a DC voltage to pay attention to the positive and negative polarity.
4. V. Fault Analysis and Troubleshooting Fault Logging Cause Analysis Exclusion Method Does not show power failure Check AB phase power supply. Wiring error between 170V and 450V. Check wiring connection failure. Check whether the voltage is not accurate between the meter and the base. Within Â±1% (about 3-4V) is normal, no need to deal with, or customize more high-precision instrument The power supply voltage is not 50/60Hz Sinusoidal AC This instrument is not suitable for non-sinusoidal AC, and the applicable frequency range is limited to 40-70HZ The metering method is incorrect. The meter displays the AB phase voltage. When measuring, it must be compared with the Ab phase voltage. The overvoltage alarm point is not allowed to display the voltage inaccuracy. See the previous misunderstanding due to the overvoltage recovery. After the alarm occurs, the voltage of the undo alarm is lower (higher) than the over (under) voltage alarm point. This may cause a misunderstanding of the normal voltage but the alarm still exists. Please check the parameter F13.
Over/Under Alarm, Over/Under Alarm Function is Off Check Parameters F11 and F12
Misunderstood voltage caused by overvoltage and undervoltage operation time The voltage must be too long or too low to generate an alarm. This time can be set. If the time is set too long, it may cause misunderstanding without alarm. Please check the parameter F21.
Phase-to-phase or phase-to-phase failures are not alarmed. Phase-to-phase or phase-out alarms are disabled. Check parameters F22 and F23 (phase-to-phase or phase-to-phase operation time is set to OFF to turn off the alarm function).
Misunderstanding caused by missing action time or wrong action time must be kept for a certain period of time to generate an alarm. These two times can be set. If the time is set to a long time, it may cause misunderstanding. , please check the parameters F22 and F23
When the phase is missing, the AB phase is not the instrument power supply. If the phase A or B phase is missing, the power loss of the instrument does not indicate normal. This meter will only be displayed when phase C is missing. It is not displayed when phase AB is missing, but it can be protected.
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