316 The N.Z. Journal of Science and Technology. [July 
there will be 20, 30, 40, and even 60 per cent, of wattless current when the 
motors of the standard makers are operating on partial loads. 
Recently a large slow-speed motor was installed on the Christchurch 
system, which for the major portion of its time is operating on nearly 
one-third or one-quarter load. This particular motor is giving us a wattless 
current of close on 60 per cent, and a power current of 40 per cent. : the 
real energy registered on the Council’s wattmeter and bringing in the income 
is only 40 per cent, of the apparent energy taken by the motor. 
Another indication of this is noted on the substation at Montreal Street, 
where there is at present 1,000 kilowatt capacity in transformers. There 
is a 1,350 kilovolt-ampere load and an actual energy- or revenue-producing 
load of 900 kw. This is due to the large aggregate of induction motors 
connected to the line running at fractions of a full load. 
Several years ago, owing to an amalgamation of companies, the prac¬ 
tice of using condensers in parallel with the induction motor was abandoned. 
Now, I claim that the large manufacturing companies have not done their 
duty to the central-station companies for some years, in that they should 
have sold condensers with each alternating-current motor but have not 
done so. Some manufacturing companies are now energetically advocating 
the use of synchronous motors, condensers, and phase-advancers to correct 
this troublesome condition. My idea, however, is that the conditions 
should be corrected by the consumer himself at the motor, and not 
have a current of low power-factor go through the transmission-lines and 
the meter to some station near by where synchronous motors or condensers 
are to be installed The real blame of getting his plant in this condition 
would naturally come back on the central-station supplier, as he has been 
so blinded by his desire to get load that he has omitted to insist that the 
manufacturers furnish motors which will not give such low power-factors. 
The result is that his prices for current are at variance with the actual 
current taken up by the consumer from the lines : there are consumers 
whose load gives a power-factor of 60 per cent., others 40 per cent., and 
others again 95 or even 100 per cent. All these consumers are charged 
a uniform rate. This is not just to the consumer giving a load of a high 
power-factor.* 
I have, therefore, to suggest to the central-station supplier that the 
charge should be made upon the current taken, irrespective of whether it 
is power-producing current or wattless current. 
Several months ago the New Zealand Public Works Department sent 
out a circular letter to all the meter-manufacturers and asked for meters 
which would record the wattless as well as the energy current on lines. 
The replies that came described combinations of energy and wattless-current 
meters, and showed very expensive instruments. All the meter-manufac¬ 
turing companies seemed to forget that the first meters that were on the 
market, of the type of the old Shallengerger meter, were of very simple 
design and would record the whole current. The indications of such meters, 
if multiplied by the voltage of the system, would give kilovolt-ampere- 
hours instead of kilowatt-hours or the units usually recorded by the 
present systems. 
* The following table shows the heating effect of current at 
with energy-supply constant:— 
various 
power-factors 
Power-factor 
Iff) 
0-9 0-8 
0-7 
0-6 
0-5 
Current in circuit (per cent.).. 
100 
111 125 
143 
167 
200 
Additional heating effect (per cent.) .. 
0 
23 56 
105 
178 
300 
