Specifications

148
Bimetallic strip - Made out of sheets of two metals, both expand when heated but at
different rates. When the temperature rises inside the hair dryer, the strip heats up and
bends because one metal sheet has grown larger than the other. When it reaches a
certain point, it trips a switch that cuts off power to the hair dryer.
Thermal fuse - For further protection against overheating and catching fire, there is
often a thermal fuse included in the heating element circuit. This fuse will blow and
break the circuit if the temperature and current are excessively high.
Insulation - Without proper insulation, the outside of the hair dryer would become
extremely hot to the touch. If you grabbed it by the barrel after using it, it might seriously
burn your hand. To prevent this, hair dryers have a heat shield of insulating material
that lines the plastic barrel.
Protective screens - When air is drawn into the hair dryer as the fan blades turn,
other things outside the hair dryer are also pulled toward the air intake. This is why
you’ll find a wire screen covering the air holes on either side of the dryer. After you’ve
used a hair dryer for a while, you’ll find a large amount of lint building up on the outside
of the screen. If this were to build up inside the hair dryer, it would be scorched by the
heating element or might even clog the motor itself. Even with this screen in place,
you’ll need to periodically pick lint off the screen. Too much lint can block the airflow into
the dryer, and the hair dryer will overheat with less air carrying away the heat generated
by the nichrome coil or other type of heating element. Newer hair dryers have
incorporated some technology from the clothes dryer: a removable lint screen that’s
easier to clean.
Front grill - The end of the barrel of a hair dryer is covered by a grill made out of
material that can withstand the heat coming from the dryer. This screen makes it difficult
for small children (or other especially inquisitive people) to stick their fingers or other
objects down the barrel of the dryer, where they could be burned by contact with the
heating element.
13.13 Repairs and Remedies:
Problems Causes Test & remedy
Unit gives no heat at
any position and/or
motor does not
operate
1. Blown of fuse
2. Broken wire/loose
connection in power
cord or in the circuit.
3. Defective switch.
4. Open circuited
temperature control/
defective thermostat.
5. Open circuted
windigs.
6. Short circuited
windings.
1. Replace with proper capacity
fuses.
2. Check all wiring connection and
cord set for its continuity. Solder
the broken wire or change the
cable/power cord.
3. Check the switch for proper
operation. If faulty, replace the
switch.
4. Check the temperature control/
thermostat. If faulty, replace it.
5. Solder the joints of the open
circuted end of the winding; if not
possible, rewind.
6. Rewind.