Most of us don't bother to do much beyond
cursing power utilities whenever a power disruption takes place. And while a
power disruption at home may not cost much-the same, if it takes place in a
commercial outfit, can run into crores of rupees. The cost of downtime for
India is estimated to be a staggering Rs 20,000 crore in direct losses
due to poor power quality and downtime.
The type of difficulties due to power
problems are Machine down time, Loss of data, Waste of Man hours. To some
extend these problems can be solved by providing power
conditioning equipments like Stabilizers and Inverters, which are the best
solutions when the equipment to be protected are not sophisticated or
Critical.
We are also dealing in Stabilizers and
inverters of various capacities. Single phase and 3 phase power
supply systems are available with us. Batteries are another important part in
power conditioning equipments like Inverters and UPS systems. All types of
Batteries are available with us. Type and capacity of batteries can be
decided depending on the type of applications and site requirements. You may
contact us for any of your requirements.
We are dealing in Suvik and Deltek make
servo stabilizers. Suvik is a Gandhinagar Based Stabilizer manufacturer while
Deltek is manufactured at Hyderabad. Both are high quality systems
available from 1 KVA to 1000 KVA capacity.
Batteries are available from 4Ah , 7 Ah, 12
Ah, 16Ah, 21 Ah, 26 Ah, 28Ah, 40 Ah, 42 Ah, 65 Ah, 66AH, 70 Ah, 100 AH, 130
AH, 150 AH and 200 Ah capacities in 12 volt category. But up to 10000 AH
batteries are available in 2 volt category.
Type of batteries available are Sealed
Maintenance free ( SMF) batteries , best suitable for UPS systems when the
backup Time requirement is low, VRLA Valve Regulated Lead Acid batteries
for Industrial applications and also when the time requirement is very high,
Tubular Lead Acid Batteries are used where temperature maintenance is
not possible at the site and also where the regular maintenance of the
batteries are possible.
Flat Plate flooded cell batteries are
used for Home Inverter applications.
Battery calculation and battery selection
can be done from the manufacturers data provided through catalogues. The
battery section chart provided by the Battery manufacturer to be refered.
The cable section is also very important
considering the amount of current the cable should carry in any electrical or
Battery wiring. Hence a sample cable size selection chart is also very
important.
Keeping your Batteries in Peak
Condition is a sure sign of longevity for your backup
solutions and besides you get the best out of your UPS. So even though your
UPS solutions are up and running and your batteries are in good condition,
over a period of time it does help if you maintain your batteries and get that
extra bit out of your aging batteries.
Why battery
Care?
-
Batteries are the weakest link.
-
Failures are mostly unpredictable.
-
Failure cost is very high.
-
Safety is the concern.
Battery
Maintenance Program.
-
Preventive maintenance – mechanical
& electrical checks.
-
Battery replacement.
-
Detailed reporting.
How will
customer benefit from the program?
-
Extended battery life
-
Early failure prediction
-
Promotes safety
Excide, Rocket, Uplus, Southern batteries,
Global batteries, Yuasa and Panasonic, AMCO, Amararaja, Quanta, HBL Nife
and Standard.
Set of procedures for
battery test
-
Note down Details of Battery and
UPS / Charger( Make , type, capacity and year of Installation,
department , site address)
-
Mark Cell Nos ( Battery nos )
From +ve final terminal
-
Physical inspection for battery
condition ; ( Check terminals, Shape of Battery cabinet, Electrolyte
Level, Spe Gravity of the electrolyte , Room Temperature) for any
symptom of problems cell nos wise. (The room temperature is to be less
than 28 Degree for VRLA/ SMF Battery)
-
Make the following measurements
while the batteries are in charging mode
Total Charger voltage, Charging
current , reading of individual cells/ batteries . (Charging
Voltage must be (13.5 to 13.75 OR 2.25 to 2.3) for VRLA/ SMF and
(13.2 to 14.2) for Tubular/ Plante/ HDLM / LA. Also measure Room
Temperature /
-
Disconnect battery bank from
Charger, Check and Correct terminal-tightness, loose contact.
Clean connectors where ever required.
-
Remove final cables from + & -
ve terminals and connect water load proportional to battery
capacity. The Discharging current will be about 20% to 30% of the
Battery capacity.
-
Put the water Load through 2 pole
MCB and measure Total DC Voltage , Discharging current and Time
-
Take readings of each cells
starting from + ve with Sr No.
-
Note down the Total DC voltage ,
Discharge current and Time at the beginning and at the end of
each set of readings.
-
Repeat the readings with Time,
Total V and I before and after taking the individual cell voltages,
till battery voltage reaches the end cell voltage of 10.8 OR 1.8
Volt
-
In-case some Cell voltages goes
bellow the limit ,very fast , isolate those cells and measure
voltages of other batteries so that the capacities of those
batteries can be found out.
-
Reconnect the Batteries in circuit
and put them on charging and measure the charging current and
ensure it is at 10% to 15% of AH capacity.
-
Prepare the report of 1. List of
bad batteries, 2. AH capacities of remaining batterers, 3. Total
Health of batteries , 4. Possible solutions for using that battery
bank
- Calculate the AH capacity of each cells based on average current discharged X time . Battery with more than 80% AH capacity is considered as good.
Selection of Discharging current for battery reliability test
1.When a battery goes bad, amount of lead on
the plate become low, Lead Oxide become Lead sulphate
and it will not dissolve and
will not covert to PbO when
charged.
2.Test the battery with 20% to 30 % of the C10 capacity
3.
Batteries are made for high discharge current.
For Example :
1. An 800W Inverter with one 12V, 100AH battery . When working
on battery, the discharging current is about of
800W / 12 V = 66Amp ie
66% of the battery capacity
2.
When a 60KVA UPS is purchased with 15 min back up you get a 60KVA UPS
with 12 volt, 100AH x 32 nos of batteries and when you need back up
it discharges with ( 60000VA / (12v x 32 Nos) =) 156.25 Amp current.
That means it discharges @ 156
% rate
3.
With an offline 600VA UPS with 12 volt 7AH battery , during power
failure it discharges with 600VA
/ 12 Volt = 50Amp ie 50A / 7A, that is @ 700%
rate
So
to know the actual capacity of the battery, we must discharge at
high discharge rate . As
it is very difficult to measure voltages of so many cells very fast ,
we cannot put load of more than 30% - 40% of battery capacity
Discharging a battery bank with high discharge rate has the following advantages
1.Internal Resistance
of the Batteries can be found out , which is not possible on low
discharge current
2.Battery will not go in to deep discharge, as
even before deep discharge the battery with high internal resistance
can be found out.
3.Inter connection
between batteries are also verified. You can see voltage drop on
terminals during high discharge current.
If
the batteries are ok in high discharge , it must be ok in low
discharge current also , but not vice versa
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