Explain the statutory regulations regarding the use of the following winding materials/equipment: i. setting of winding machine ii. Liquid varnish iii. Oven – NABTEB QUESTION

Answer

i. setting of winding machine

a. Steady speed should be maintained to allow smooth and equal tension on the former for good construction of the coils.
b. The winding machine should be placed on a flat surface for good operation.
c. The use of correct former size for the construction of the coils.
d. Fix the former properly to prevent shaking.
e. There should be proper illumination for the operator of the machine to work effectively.
f. There should be proper alignment between the former and the cable reel to prevent the twisting of the copper conductor.
g. The counter should be set at zero.

ii. Liquid Varnish

a. Electrical machines can only be varnished after it has been wound, soldered, branded and tested.
b. Varnish is used on wound machines coil to prevent or reduce the following

i. moisture on wire insulation.
ii. vibration of the coils of wire in the machine slots.

c. Varnish must be allowed to dry before the use of the machine. For instance, if an air dry varnish is applied, the machine is placed on the workbench to dry and if the ovens dry the machine is placed in the oven dry.

iii. Oven

a. The oven must be set to required temperature before the varnished machine is placed on it.
b. The oven must be closed when in use
c. Flammable materials must not be placed near the oven during the operation
d. Only oven dry varnished machines are baked in it.