IEEE Power & Energy Magazine - September/October 2020 - 96

for a 50-cycle distribution. Eventually,
improvements in machine designs enabled a single frequency to be used for
both the lighting and the motor loads.
The frequency of the electric current
generated at Mohra was kept at 25 cycles
for the future possibility of using it for
a railway traction line connecting Srinagar. However, owing to an unbearable flicker in arc and carbon-filament
lamps that resulted from the low periodicity of the current, it was desirable
that a higher-cycle current be used.
Hence, the frequency was doubled
from 25 to 50 cycles. Two frequency
converters, one with a capacity of
100 kW and the other with a capacity
of 200 kW, were utilized for this purpose (Figure 9). The 100-kW frequency converter consisted of a three-phase,
2,300-V, 100-kW, 50-cycle alternator
directly coupled to a th ree-phase,
2,200-V, 150-hp, 750 r/min, 25-cycle
induction motor.
When the Mohra Power installation
began operating, a substantial amount
of its power was used for the dredging operations at Baramulla. Later
on, when the dredging operation was
discontinued, the Mohra power plant
started supplying a large lighting load.
Srinagar, being the capital, provided
the principal load. On the way to Srinagar, several lines branched out: hightension lines fed the receiving station

at Baramulla (1914) and continued
from there to other towns [Doabgah
and Sopur (1918)] in one direction and
Gulmarg (1917) in another and later
reached Pattan (1929). As the lighting
loads increased in Srinagar, the frequency-changer plant was shut down
due to its inadequate capacity. The city
and its suburbs had a 25-cycle supply for both their lighting and power.
During the 1920s, the Mohra installation worked at only two-thirds of
its capacity; however, the demand for
power was gradually increasing. The
total daytime load at the silk factory
substation was roughly 1,700 kW; the
lighting load of the whole city and
its suburbs was 600 kW. There were
approximately 2,750 residential consumers and 12 mills. In 1933 and 1934,
the total connected load increased to
4,000 kW, and the bulk of the demand
was from Srinagar.
Residential consumers were provided with a single-phase, 220-V supply. All lighting installations had to
have either meters or current limiters.
Heaters, fans, and domestic appliances
required separate metering. The rate
for lights was 6 annas per unit, or 11
annas per month (night supply only) for
a 20-W lamp in addition to the meter
rent of 8 annas per month (1933). The
electric connections were provided for
a minimum lighting load of 40 W, but

figure 9. A frequency-changer set and lighting switchboard, Srinagar City.
(From S. Narayan, The Hydro-electric Installations of India, India, 1922, p. 61.)
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ieee power & energy magazine

as the demand grew, only two light
bulbs were allowed. (Note that 1 rupee
totaled 16 annas then.) The 25-cycle
electrical power from Mohra was inadequate for proper illumination and the
correct functioning of modern equipment. With 50-cycle electricity generation starting at other places (Ganderbal, 1955), two separate zones had to
be created, and the power generated at
Mohra was exclusively used for mills
and silk factories. The two generating
sources (Mohra and Ganderbal) were
not synchronized until 1962.

Silk Factories
Large silk factories were located in
Srinagar (Figure 10). At that time,
Srinagar possessed the distinction of
having one of the largest silk factories
in the world, employing some 3,300
people and producing 200,000 lb of
silk per annum. Wood-fired steam engines powered looms and warpers and
heated the silk-filature basins to dissolve the binding substance that held
the fine cocoon threads together. The
wood consumed by the boilers exceeded 1 million lb annually, which put a
major strain on the valley's fuel supply.
It was decided to use electric power for
heating the filature basins in which the
cocoons were immersed for reeling.
But very little had been done in this
direction, either locally or in Europe.
There were two obvious methods for
using electric power for heating: channeling it to the boiler instead of using
wood and heating the filature basins
directly by sending electric current
through wires.
There was a high chance that a
breakdown in the boiler that supplied
all the filatures would shut down
all the basins. The second method
of heating individual filatures was
seen as the best option. Crompton and
Company, London, was asked to design the heating system, which would
automatically cut off the current at a
certain temperature, and the manufacturer was given the particulars of the
filature basins and the required heating
level. Initially, a few samples of heaters were requested from the company.
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IEEE Power & Energy Magazine - September/October 2020

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