DAIRYING COSTS

New Zealand Herald, Volume LXXIII, Issue 22349, 21 February 1936, Page 19

DAIRYING COSTS

POWER IN THE SHED CARE OF ELECTRO-MOTORS SAVING THAT CAN BE MADE BY PAN To bridge the gap which still remains between production costs and price the dairyfarmer must eliminate every avoidable expense, however small. A case in point is tho large number of farm motors which have to be rewound. This is a matter of great importance for it increases the costs of production to a serious extent. It is a preventable loss duo largely to carelessness and wrong methods in operating tho power units. Let us examine some causes of these breakdowns. One of the first is faulty lubrication. Many motors are fitted with ring-oiling bearings. These should be drained and refilled with suitable oil every three months. Too often they are not emptied at all, fresh oil being added at long intervals with the result that tho old oil loses its lubricating qualities, becomes thick and sticky so th&t the oiling ring refuses to run around with the spindle, and the bearing is soon drv and worn. Then the oil finds its way along the spindle until it reaches the pulley which operates it upon the insulated windings of the motor. This oil quickly destroys the insulation, short-circuiting is set up, and the motor burns out. Oil on Pulley End A coating of oil upon the pulley end of the motor is a sure sign of a worn bearing. A similar result is produced by having the motor belt too tight. This condition is generally due to the motor being set to run the wrong way, causing the slack of the belt to be underneath instead of on top. In this case the belt falls away from the small pulley and so embraces it for only about one-third of its circumference instead of two-thirds as would occur if the Black was on top. Hence the belt has to be kept very tight to avoid undue slip. In such an instance it may be possible to cross a belt in the transmission system, and by transposing tho motor leads, reverse its direction of rotation.

Trouble also occurs if the motor is fitted with roller bearings packed with grease unless the lubricant is removed at stated intervals. Another cause of failure is loose contacts due to vibration and the action of electrolysis. When the contacts become loose, current is wasted and the contact surfaces are gradually destroyed. While this action is taking place certain sections of the motor windings become over-loaded and eventually Durn out. The Worst Enemy Water is, of course, the' electrician's worst enemy and these power units must be kept clean and dry. Too often they appear to be neglected in this respect, being covered with dust and old oil interspersed with splashes of milk and water. The result is a sudden breakdown entailing costly repairs. While a dairyfarmer is not usually a skilled mechanic, still he can do much to ensure the sweet running and long life of his electro-motor. Like the cream separator it should be wiped clean daily and m(*ahs employed to prevent splashes of water reaching it while washing down the room.

Another serious loss is due to the burning out of small motors used to drive cream separators. These require careful treatment if long life and efficient working are to be obtained. When starting up the separator do not engage the clutch too tightly and* also give the machine a good start by pulling on the largp driving wheel by hand. A point to remember is that all small motors —those without starters — must run at full speed immediately the current is switched on. If they do not do this the strain upon the windings is very great, causing the insulation to break down sooner or later, and a burn-out occur.

Regulations require the supply authority to inspect all milking-shea installations at least once in three years. This period is too long for much damage may be done in a shorter period of time. On the principle that a "stitch in time saves nine" it will pay all dairyfarmers to have their plants inspected by a competent electrical machinist once each year. The cost would be small compared with the increased efficiency and longer life of the motor and electrical installation.