Heating of Dynamos

— The exce ive heating of the constituent parts of a dynapa eBO: mo is probably the most common and at the same time the most annoying fault which arises in the working of the dynamo. It may be due to various causes, electrical or mechanical; and may eccur in any one or more of the component parts of the dynamo: (1) Con= nections. (2) Armature, commutator, brushes. (3) Field magnets. (4) Bearings. ‘ _It may be detected by applying the hand to the different portions of the machine if low tension, or a thermometer if high tension, and also by asmell of over-heated insulation and paint or varnish. When this last indication is noticed, ıt is” advisable to stop the machine at once, otherwise the insulation is liable to be destroyed.