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Topics: Frequency inverter request on Inverters
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10-16-2012 10:50 AM

Frequency inverter request

I am stating following questions as they are important for our operational requirement.

1) The frequency inverter will be used for constant pressure pumping of agricultural water, 6 to 8 hours a day. The feedback of pressure will be through Rs 485 (Digital PID)

2) Send me - Input /Output stable continuous amp rating for the models you offer. Please confirm True Ampere rating and not RMS current rating.

3) In 3 to 3 phase frequency inverter, we run 4 hours a day with 2 phase supply only, based on availability conditions. Conform trouble free operation.

4) All through digital mode on rs 485. (Set pressure, feedback pressure, speed up/down and other functions) Confirm protocol supported/offer able.

5) For single phase models, confirm dc input possibility. Is there a possibility of 24/48/72/96 Volt DC, for future conversion to Solar / wind power generation?

6) In 3 phase Input to 3 phase output inverter, we run 4 hours a day with 2 phase supply only, and 4 hours on 3 phase grid supply, based on grid availability conditions. Conform trouble free operation.


1. Can I enable / disable (phase loss function) to achieve my above requirement. Can this function be removed / enabled thro soft command on rs 485? As and when required, while the inverter is in operation……??

a. Will it affect the frequency inverter performance or life..?

b. Assuming that I install a over rated inverter to take care of additional current drawls during phase loss (as well as low voltage) is there a need or case to install a higher rated capacitor in the inverter..

c. If capacitor needs to be overrated, for my application, to ensure stability, is this doable within the frequency inverter / externally??

2. While the inverter is running in 3 phase normally, and a phase loss occurs, will the frequency inverter be able to hot change on the run?

3. If a phase swap (Reversal) occurs in the input side(offline), will the inverter output phase be affected and motor reversed?

4. If inverter is overloaded on input side / output side current rating, will the over current trip function happen as per factory setting OR soft setting by us..?

a. After trip, can the frequency inverter be made to restart after a set time duration automatically OR through soft command thro RS 485..?

b. If frequency inverter is operating on unsafe temperature, will the over temperature trip function happen as per factory setting. After trip, can the inverter be made to restart after a set time / temperature drops down to operational level automatically?

5. Can you offer us Power metering (KWH) function built in the frequency inverter?

Note :
a. Send us RS 485 / Modbus – other protocol details and command set.

b. Product certifications / test certificates / nominal operating instructions.

Thank you and wish you the best and looking forward to doing business for a long time to come by.

Warm regards,
10-16-2012 05:54 PM
Top #2
10-16-2012 05:54 PM
For few answers:

the single phase frequency inverter do not support DC input.

1) do NOT support phase loss function through soft command.

The loss phase operation won't harm our drives & performance.

For over rated inverter, it's no problem if the total current in the inverters rated current range, do not need additional capacitor.

2) It can work same as three phase, nothing happens.

3) It's the input reverse, won't affect the inverter output and the motor direction

4) overload & overheat is detected by hardware, can't be set by soft command, the frequency inverter can't restart automatically after trip for both overload & overheat.

5) The cover is compact, we don't think it has space for the power meter built.

Suggestion: for safety factor in loss phase operation, we suggest you use a bigger level inverter, like for a 3.7kW motor, use a 5.5kW power to control it.
11-17-2012 11:26 AM
Top #3
11-17-2012 11:26 AM
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11-19-2012 03:03 AM
Top #4
11-19-2012 03:03 AM
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