SAADZZZ,
Noise from Fan: Let me explain this first: we have three sorts of loads,
- Resistive load,
- Inductive load
- Capacitive load.
- Basically in Resistive load the voltage and current waveforms are in phase with each other and these UPS works very well for resistive loads such as Bulbs, computers etc.
- In Inductive load, Voltage wave forms lead the current waveform which can be described as lag behavior of current waveform. Fans, motors falls under the category of inductive loads.
- Third, are capacitive loads where current waveform leads the voltage waveforms.
Fans connected with UPS falls under Inductive load, since power factor of power line is affected once you turn on the fans that why you hear strange noises coming out from fans. This problem can be addressed by adding a capacitor with fans but since I have never dig further down so canât help you out. Capacitor antis the lag behavior of current waveform and carefully adding a right capacitor can help.
HOW TO CONTROL BATTERY CUTOFF VOLTAGE AND VOLTAGE ON UPS POWER LINE DURING LOADSHEDDING
In second Image, you can see two buttons which can easily be rotated with a screw driver namely âBATTERY FULLâ and âMAIN LOWâ. Let me explain how these buttons can help you and how you need to Adjust UPS system.
I am considering that your UPS is connected with two batteries in series and requires (12 +12=24) Volts battery bank.
BATTERY FULL:
With Voltmeter set to measure DC Voltage with appropriate range. Connect the one lead with positive terminal of one battery and one lead with negative terminal of another battery, since they are in series. Batteries should be fully charged at that instant and UPS should not be charging it any more. Now, put the entire load on UPS by switching off the AC power which goes to the UPS. And after 6-7 seconds then turn on the switch and let UPS charge the battery. Now see the voltage across the terminals and adjust such that once Voltage reaches 28 Volts or 28.2 Volts then it should cut off the charging and go into hibernation. You may have to repeat this step several times till the time you donât achieve the right Voltage. This is how you adjust the cut off Voltage during charging and I am very positive if you understood how to do it then it will save you from lot of trouble from calling the electrician again and again.
Donât do anything wrong, If you donât have an experience in measuring Voltage then these directions are not for you.
MAIN LOW
This button is also very important as it adjusts the output voltage in UPS line during load shedding. Considering that your UPS consist of two battery bank and are in healthy condition. Adjust the knob on Voltmeter to measure AC Voltage and set it appropriate range. Batteries should be in fully charged condition. Ask your brother to insert the voltmeter leads on UPS line measuring some xyz Volatge. Now, put the entire load on batteries by turning off the AC switch just like its happens during loadshedding. Ask your brother to tell you the Voltage on AC line and start rotating this switch â \MAIN LOWâ such that output registers 250 Volts and adjust it there. Non of the sensitive equipment should be attached with the line once you are making the adjustment. We need 250 Volts because this Voltage will start to drop as soon as the batteries will get week and we want UPS to beep and shutdown once Voltage reaches 220 Volts. This is only done by ensuring that Output Voltage should be around 250 Volts. Rotate the switch slowly and tell your brother to constantly keep on telling you the Voltages. Donât do anything stupid and you can adjust it somewhere between 250 Volts to 260 Volts. Now your computers should be safe under these conditions.
ADJUSTING CHARGING CURRENT:
Now this is little tricky and easy as well. But since, your connections are little different than mine so I would indicate it to you how we adjust the charging current but further you will have to verify things from your UPS technicians. Once he will be doing it then Note it down so that you donât forget it next time. In 4[SUP]th[/SUP]-Image, on top of transformer there is a small box with few wires going into it from Transformer. Now you can see one slot empty where as in my UPS there is 2 slots empty with one slot connected to one wire. Three options are normally available with these UPS, one adjusts the charging rate to somewhat 5 AMPERES, second adjusts the charging rate till 12 Amperes and last one adjusts it to 16 to 18 Amperes. Usually that one wire is taken out and inserted into the other option. But once I do this exercise then I simply put the cables off from batteries and turns the AC power off from UPS line.
I hope, this will help.
