TDS level in drinking water

TDS stands for total dissolved solids.TDS represents total concentration of disolved solids in the water.

TDS is made of up inorganic substances and small amount of organic substances.

The inorganic substances refers to the  salts and heavy metals.

How to measure the TDS ?

TDS in water can be measured using portabal conductivity meter. The another name of this meter is TDS meter.

How to control the TDS level in water ?

TDS can be controlled using reserve osmosis process.but the main drawback of this process is more wastage of water I.e. reject water.

Unit of TDS :

TDS will be showcased in the term of ppm (Parts per million) or mg/l (milligrams per litre)

 TDS level :

EPA (Environmental Protection Agency)

As per the EPA, 500 ppm is maximum acceptable limit

WHO(World health organization)

As per the WHO, 300 to 600 ppm is  considered as good and the level more than 1200 ppm is considered as unacceptable 

BIS(Bureau of indian standards)

As per the BIS, 500ppm is maximum acceptable limit.

ICMR(Indian Council of medical research)

As per the ICMR, the value between 500 ppm to 1500 ppm considered as good.

Hope the above information is much useful to you.

Thanks for reading this topic.

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Ashokraj S

KVAR rating calculation to design the APFC Panel

How to calculate KVAR rating for APFC Panel ?

APFC Stands for automatic power factor correction/controller 

KVAR stands for kilo volt ampere reactive 

Assume that your electrical  distribution system have the value of 100KVA,415V,240.96 Amps and PF is 0.8.

If we want to improve the power factor from 0.8 to 0.99, you need to install the static capacitor in the existing  system. 

There is a standard formula to calculate the required KVAR i.e. 

KVAR =P(Tan pi 1 - Tan pi 2) 

Let us assume Cos Pi 1 = 0.8 

                                  Pi 1 = cos inverse of 0.8

                                  Pi 1 = 36.869 

Also let us assume Cos Pi 2 =0.99

                                       Pi 2=Cos inverse of 0.99

                                       Pi 2= 8.109 

Now apply all the known values into the KVAR standard formula.

KVAR= 100( Tan 36.869 - Tan 8.109)

          =100(0.749-0.142)

          =100(0.607)

          =60.7

So, to improve the power factor from 0.8 to 0.99, we need to install at least 60KVAR capacity of APFC panel in the electrical system.

Thanks for reading this topics.

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Ashokraj S 

APFC in Electrical Systems

APFC panel in Electrical System

 APFC stands for Automatic Power factor correction/Controller.

APFC Panel used in electrical power distribution system to improve the power factor from lagging PF to near to unity PF.

Power factor is the ratio of active power to the apparent power .It is denoted by cos Pi

Cos Pi = KW/KVA

Where

 KW is equals to 1.732 x V x I x Cos pi (or) V x  I x Cos pi

KVA is equals to V x I 

Thanks for reading this topic.

1 TR = 400CFM ?

Hi All,

Generally we are using 1TR =400CFM in most of our HVAC system design. But which is wrong and there is no theoretical calculations on this too.

Before discussing further, I just want to describe what is TR and what is CFM.

TR is called as ton of refrigeration TR or refrigeration ton RT. TR means amount of heat extracted to produce one ton of ice.

CFM is the unit of measure of air flow, CFM stands for cubic feet per minute. CFM means volume of air entering the room in a minute. 

Coming back to the topic, 1 TR may be equal to 400 CFM or 300 CFM or 450 CFM or some other value . It will differ one manufacture to another manufacture .

However, there is a standard equation available to relate the BTU/HR and CFM .

BTU/HR=1.08×density correction factor ×CFM×Delta T 

Where,

1.08 is constant for air at standard condition 

Delta T is difference between inlet and outlet air 

CFM is cubic feet per minute 

By using the above formula, we can calculate the CFM for any TR cooling equipment. 

I would like to add another point that as per the ASHRAE,we don't have any formula to relate the TR and CFM.

As per the human comfort standard, 1TR of air conditioned should have a discharge of air 400 CFM .If we discharge below 400CFM,the people who using the equipment will feel suffocated even though we maintained low temperature. 

The conclusion  of this topic that if we want to calculate the CFM of equipment roughly, please use the below thumb rules or otherwise you want to calculate the CFM exactly ,please use the equation 1 .

For centralized air conditioning system 

1TR =400CFM 

For non centralized air conditioning system 

1TR=300CFM 

Thanks for reading our blog post. Please post your doubts in the comment box if any.

By

Ashokraj S

Why night lamps called as zero watts bulb, even though it consumes some amount of power ?

There are four different types of lamps available in the market .

1.Incandescent lamp

2. Fluorescent lamp

3.Compact fluorescent lamp

4.LED lamp 

Among these types, we are mostly used incandescent lamp as a night lamp.

Actually low intensity incandescent bulb are called as Zero watt bulbs and there is no lamp with zero watt consumption.

Even a small LED indicator consume power,though it is a fraction of a watt.

The zero watt lamp actually consume 15-20W.

In earlier days, we were using only zero watt lamp at night and other loads were kept off at home .In such case, the conventional type electromagnetic energy meter could not record the energy consumption because the disk inside meter did not move when the load was only with 15 Watt.

But in our modern life, we are using the digital energy meter and it is  capable of capturing in fraction of watt.

My recommendation is to procure the LED type zero watt bulb for your home instead of incandescent lamp . LED type night lamp will consume less power i.e 0.5 W or 1 W and you can save the electricity here and there by we can save your money too.

Thanks for the reading!..

By

Ashokraj S 

BE EEE

What is star rating in electrical appliances and what is EER and its calculation

Buying a new air conditioner and electrical appliances is really a big task for all.Because if we procure bad product then it will hit our electrical bill more high than usual.

So we need to check few parameters before buying the product. The parameter such as star rating, energy efficiency ratio, seasonal energy efficiency ratio,indian seasonal energy efficiency ratio etc..

 Star Rating:

The government of india was launched the BEE bureau of energy efficiency in the year 2002 under energy conservation act 2001.

The main moto of BEE is to reduce the power intensity with indian economics and to promote the use of energy efficiency equipments. 

To promote the equipments,they introduced star rating system. The star values from 1 to 5.

The highest star rating represents the maximum efficiency of the equipment. 

After introducing this, many manufacturers were voluntary involved in the star labeling programme to get the more customers. 

All the electrical appliances ( TV, AC, LED lamps, heater, refrigerators etc.) would have this star rating.

EER:

Energy Efficiency ratio is defined as ratio of output cooling energy to the input electrical energy at given operating points.

EER is generally calculated with 95 degree F out side temperature and inlet temperature of 80 degree F and 50% relative humidity.

If you see the home air conditioners, there would be lable on it and it contains  the value of star rating and values of EER.

But after Jan 2018, the BEE was also introduced ISEER (indian seasonal energy efficiency ratio) because AC willbe operated maximum at summer season and  operated less at rainy seasons. 

We willbe discussing later about SEER and ISEER..

Let us see how to calculate the EER if you know value of TR and KW.

Example 1:

If 24000BTU capacity of AC  is operated under 1200W power,then what would be the EER? 

EER =(Cooling energy in BTU)/(Electrical energy in watt)

= 24000/1200

EER =20 

Example 2:

If 24000BTU capacity of AC  is operated under 2400W power,then what would be the EER? 

EER =(Cooling energy in BTU)/(Electrical energy in watt)

= 24000/2400

EER =10

From the above examples,  we need to understand that we need to checkup the EER and star rating while we purchasing the new AC for your home.

Thanks for reading !...

By 

Er. Ashokraj S 

Difference between MCB & Isolator

MCB:

MCB is Miniature circuit breaker,which used to  protect the electrical equipment from over load and short circuit conditions.

There are 5 type of MCB in the market based on the magnetic trip current,

1.Type B

2.Type C 

3.Type D 

4.Type K 

5.Type Z 

Based on the applications and demand, we are using the MCB's in domestic & industrial area.

There are two trip unit available in MCB, there are thermal trip unit and magnetic trip unit.

When over current is drawn by the electrical equipment, thermal trip unit trip the MCB,whereas magnetic trip unit will trip the MCB when the short circuit occurs .

Isolator :

Isolator used to isolate the electrical equipment from power supply or electric current for servicing and maintaining the equipments.

There is no protection system available

If over load occurs, the isolator will burns out.

Difference between MCB and Isolator:

        MCB                                   Isolator 

1. Automatice device        1.Manually operated 2.Protection available      2.Not available 

3.High Cost                           3.Low cost

4.Electronic circuit            4.Mechancial device 

made by transistors             act as switch

5.Arc suppression              5. Not available 

mechanism available 

6.High current                    6. Low current 

withstand                                  withstand 

capacity                                     capacity 

7.ON load device                  7.OFF load device

Please comment if you may have any doubts.