Power Engineers is known for
reliability and continuous improvement in the field of rolling contact
type automatic voltage controller, servo voltage controller,
automatic
voltage stabilizer, chemical process rectifiers,
electroplating
power rectifiers and special purpose transformers. The systems are
designed and supervised by a team of qualified engineers having more
than 35 years of experience to achieve best possible quality and total
customer's satisfaction.
Inspire of best efforts, no state
electricity board can ensure constant voltage to the customer because of
long and inadequate distribution lines and irregular load pattern on
distribution transformers. Generally Voltage is low during day time and
high during night hours. Moreover on holidays, peak hours, rainy days
and when agricultural and industrial load is switched off, the voltage
rises sharply which is more dangerous.
» This higher current
affects the electrical motors (particularly smaller capacity motors upto
7.5 H.P.) in three ways
- Higher current produces higher losses in electrical motors which
cause premature failure of winding.
- These higher losses of electric motors also increase the losses
of cables, switches, transformers and other associated equipment.
- For smooth continuous operation of motors, over load relays are
usually set at 20% higher setting.
With the installation of the stabilizer and maintaining 390/400
volts, the motor will operate smoothly drawing 15 - 20% lesser current
and correspondingly the relay setting can be reduced by 15 - 20%. In
case single phasing occurs, the relay will trip in 40 - 50 seconds. The
motors can withstand the high current for this period and will be safe.
Also, the relays, contactors, switchgears, etc. incorporated with the
motor will be safe.
» Effect of Unbalanced Input
Voltage between Phase to Phase
Industrial units situated in residential / commercial areas and not
having their own distribution transformer, have the problem of unbalance
input voltage between phase to phase and many have the problem of
frequent failure of three phase motors. Normally unbalanced input
voltage problem persists for few hours a day and will have the following
effects on the three phase motors:
- With 5% Unbalanced Input Voltage between phase to phase - the
LOAD will be unbalanced and the capacity of the motor reduces by
40%.
- Consumption of the three phase motor will increase by 20 - 25%.
To avoid frequent tripping of the
overload relays and to continue production, setting of motor relay is
kept higher than actual required. The motor (particularly smaller motors
upto 7.5 H.P.) cannot withstand this high current for long time and in
most cases the motor burns out and this high current flows through the
relays, contactors, cables etc. resulting in failure of the same and in
some of the cases may cause fire also.
The best option for such Units having Unbalanced input voltage, is to
install
servo
voltage stabilizers and servo voltage controller with individual
phase control.