Voltage Stabilizer, UPS, battery backup recommendations please?

[kartechnology]

Yes

cost? is it with the additional buckboost transformer or just the servo auto-transformer..pls post pics if u have,

i bought this 10kva for 22k in 2021, from varshanic chennai, with MOV added for surge protection. custom built case size as per my requirement. upto 300v input

I am thinking to buy a static one for home, probably a 5kw-3 phase one(triostat) if under budget or a 7.5kw single phase

 

[Phani24]

 

[Phani24]

Cost 27k.

 

[kartechnology]

got a quote from numax for
7.5kw ~195-264v~ 33.6k
7.5kw ~184-276v~ 39k
10kw ~184-276v~ 46k

where as sunpower-surat - 7.5kw 65k+gst and 10kva 58k+gst, no range mentioned
already one forum member has bought from nkb 5kw for 45k+gst, a 175-285v range

i am thinking to go with the 7.5kw 184-276v for 39k. asked for dark gray cabinet. its the closest to me in case of service access. they claim it has surge & spike protection, need to see if that's by default or just marketing, asked for internal pics. even though i think its a bit expensive still, i hope it will save me from getting any future issues with inverter ACs (mitsubishi heavy), and sony x90L, and other connected equipment.

 

[kartechnology]

Static stabilizer 7.5KW from numax... Will install tomorrow and share pics... Very good build quality

 

[kartechnology]

Filters and MOV's



uninyvin cables used inside - current rating max 43A

Installer came to install the very next day of delivery. good service and he's like they have improved the design and now failure rate is pretty less. as per him most installations are in petrol bunks and they imbalance it (3 phase stabilizers) causing the igbts to fail, harsh conditions. cabinet design is also new, easy to access panels. fan will run only after 60-70 degrees heatsink temperature. no noise.

i have the option to view the display over wifi and data logging, inputV, outputV, load% and any fault conditions. can remotely turn on/off the output

 

[mbhangui]

View attachment 84948View attachment 84949
Filters and MOV's


View attachment 84950
uninyvin cables used inside - current rating max 43A
View attachment 84951View attachment 84952View attachment 84953View attachment 84954
Installer came to install the very next day of delivery. good service and he's like they have improved the design and now failure rate is pretty less. as per him most installations are in petrol bunks and they imbalance it (3 phase stabilizers) causing the igbts to fail, harsh conditions. cabinet design is also new, easy to access panels. fan will run only after 60-70 degrees heatsink temperature. no noise.

i have the option to view the display over wifi and data logging, inputV, outputV, load% and any fault conditions. can remotely turn on/off the output

View attachment 84955View attachment 84956

Well constructed and neat. Nice to see some quality product.

 

[kartechnology]

Our forum member who bought nkb technocrats 5kw if they could open the unit and share pics, can see if the cost they charge is justified with difference in quality...igbt need to be checked if same or different..

 

[funnyprogrammer]

i have the option to view the display over wifi and data logging, inputV, outputV, load% and any fault conditions. can remotely turn on/off the output

How can you access it over WiFi? I bought 5kv unit from them.
Is there anyway to turn off display as well?

 

[kartechnology]

How can you access it over WiFi? I bought 5kv unit from them.
Is there anyway to turn off display as well?

Many manufacturers didn't still start the server hosting for customers as they find it additional expense. You may try contact the manufacturer, they will give additional esp8266 chip connected to the display port and unplug the display lcd. Web data upload feature might not be available with them, but it is supported fully. They might have only local web access.

Yes you can simply unplug the display, a 4 wired connector.

Can you open the unit and share some pics? I want to see why they priced it so high than numax..igbt, transformer rating, filters, mov,

 

[funnyprogrammer]

Can you open the unit and share some pics? I want to see why they priced it so high than numax..igbt, transformer rating, filters, mov,

Even I got Numax. Will check with them regarding wifi adapter.

 

[kartechnology]

Even I got Numax. Will check with them regarding wifi adapter.

Price for stabilizer and kw, input range? When did you purchase ..

I didn't get the wifi adapter from numax, i had built mine as i had built wifi communication from quikorrect dsp<->esp8266 during development with the original parent company(Medi, kerala). Let me know how much numax is charging for the wifi adapter.

I have a concern that the LEDs for 2 igbts are flickering and dull. Also I see some faint flickering in the led lights in my home when I observe closely which isn't present on direct grid. I'm afraid if this investment is a good one or it is giving out bad output waveform

 

[funnyprogrammer]

Price for stabilizer and kw, input range? When did you purchase .

In May, 5KVA for 29k. 180-280v range. Output : 230

 

[kartechnology]

In May, 5KVA for 29k. 180-280v range. Output : 230

I'm having already issues with the output. Unit transformer buzzing, igbt LEDs flickering and connected tube lights/bulbs flickering like unstable grid where as the actual grid is completely fine! Duh. Shouldn't have gone for this and got the servo instead. Contacted numax waiting for reply. Tech did see that during the installation but was quiet. Now he says Monday he will visit..i Believed in this and removed all my ac ,tv stabilizers.. Now all running in bypass (didn't even provide that, had to manually bypass)

 

[sayan00]

I am using a 5KVA static stabilizer from NKB Technocrats, for the past one year. It works just fine, low noise and no issues so far. I have an entire home theatre system connected to it. The owner of the company is also very helpful and will listen to your requirement before recommending a solution. Online reviews seem to be good for this company.

 

[kartechnology]

I am using a 5KVA static stabilizer from NKB Technocrats, for the past one year. It works just fine, low noise and no issues so far. I have an entire home theatre system connected to it. The owner of the company is also very helpful and will listen to your requirement before recommending a solution. Online reviews seem to be good for this company.

yes but nkb is expensive. now even numax responded they will check the unit and will send a service person to inspect, lets see..do u have transformer buzzing noise kind of or high freq noise close to the unit? how are your input voltages usually

 

[sayan00]

yes but nkb is expensive. now even numax responded they will check the unit and will send a service person to inspect, lets see..do u have transformer buzzing noise kind of or high freq noise close to the unit? how are your input voltages usually

They must have a reason behind their pricing, best to ask them directly. They also gave a detailed test report of the unit before sending it. There is a very low noise from the unit (5KVA rated), I feel its not significant, although YMMV depending on your hearing sensitivity. Actual Input voltages vary between 229-252 volts, that is what I have randomly observed.

 

[kartechnology]

They must have a reason behind their pricing, best to ask them directly. They also gave a detailed test report of the unit before sending it. There is a very low noise from the unit (5KVA rated), I feel its not significant, although YMMV depending on your hearing sensitivity. Actual Input voltages vary between 229-252 volts, that is what I have randomly observed.

cost would be copper winding transformer, a 2 pole mcb, and maybe additional EMI/RF filters, or bypass switch...there was no test report..

basically this unit has few MOV and capacitors to filter out the harmonics produced by the unit itself.

and its quite possible to easily over-rate these devices as the max kva can be set by the setup menu fairly easily. the designed transformer seems to be of 1.3kva which translates to 6.5kva max load. this technology takes in a transformer of 1/5 of total capacity. and they rated this as 7.5 and menu setting is 8kva...it will work at the cost of component damage if it exceeds design capacity of the igbt and transformer..

more details can be found here, the deisgner of this tech in india
http://www.magicsineferrite.com/attachments/article/48/QUIKorrect Doc.pdf

reason to choose numax was service support...and didnt expect to have issue immediately..

 

[Musicforsalvation]

Transformer in itself is a major factor in such equipments. Apart from winding material (aluminium or copper) , it's insulation, wire thickness, purity, core material and lamination grade etc decide the cost , performance and efficiency.

Like all the members here, I am also using NKB 5 KVA system from more than a year now. Never ever faced any issues. The system came in a solid wooden crate and was extremely easy to install by following the user manual.
Voltage here fluctuates anywhere from 180 to 250 but the system has always given constant output without even a trace of flicker and is dead silent....
They clearly have installations and service support all across the country. Even saw some excellent reviews from their overseas clients.

Numax system having major performance issues right away rightly raises questions on material quality IMO. It clearly wasn't built and tested properly before delivery.

Generally speaking, I don't think any company would be able to tag and sell their product at a higher price if their quality doesn't have substance. Sayan is right, NKB must have reasons behind their pricing.

 

[Nitin K]

I am using NKB 5kva for approx 1.5 years. No issues so far and cannot hear any noise from mlp. Input voltage on an average is 245v touching 252v occasionally. Output correction is 230v or 231v.
Will update after a year regarding durability.