Section B - Accessories - Electrolux 30" Service Manual

SECTION B - ACCESSORIES

Fluorescent lamp:
The fluorescent lamp circuit located in the backguard is
made up of a switch, starter, ballast and a fluorescent
light bulb.
L1
Switch
How the fluorescent lamp circuits operates:
When the contacts of the switch are closed power is
applied to one of the filaments of the light bulb. The
filaments of the lamp are connected by the contacts of
the starter. When current starts to flow the open con-
tacts of the starter close. This means the filaments are
connected in series with the circuit that is completed to
neutral through the winding of the ballast. The first few
seconds after the switch is closed current flows through
the filaments, starter and ballast. After a few seconds of
current flow three things happen. The filaments are
heated so they can emit electrons, the contacts of the
starter open and the windings of the ballast builds a mag-
net field. When the starter contacts open, current in the
circuit is momentarily interrupted. When the current is
interrupted the magnet field around the windings of the
ballast collapse inducing around 180 volts into the cir-
cuit. This breaks down the dielectric of the light bulb
allowing electrons to flow between the filaments causing
the light to glow. With current again flowing in the circuit
the windings of the ballast place impedance in the cir-
cuit lowering the current flow in the circuit to make it
more efficient.
Troubleshooting the fluorescent lamp circuit
Two common failures that occur in a fluorescent lamp
circuit are:
The light bulb flickers or only glows at the ends:
1. This is usually caused by either a defective bulb
or starter. To determine which part is defective
close the switch and allow the light to act up. Then
remove the starter. If this corrects the problem the
starter is defective, If the problem is not corrected
change the light bulb.
Bulb
Ballast
Starter
Light bulb does not glow:
1. Remove the light bulb and check the continuity of
the filaments. If either of the filaments are open
replace the light bulb. If the filaments check good,
go to step 2.
2. With the switch turned on measure the voltage drop
between each terminal of the switch and neutral. If
N
the meter reads zero from both terminals the wire
between the L1 terminal block and switch is open.
If the measurement from one terminal reads 120 VAC
and the other reads zero the switch is defective. If
the meter reads 120 VAC from both terminals go to
step 3.
3. Disconnect electrical power from the range and
reinstall the bulb. Remove the starter and drop the
starter socket down so that a meter probe can be
inserted into the terminals. Measure the resistance
between the output terminal of the switch and the
terminal in the starter socket that is connected to
the filament that is connected to the switch. If the
meter reads open the light socket, the starter socket
or the wires between the two are open. If the meter
reads zero go to step 4.
4. Measure the resistance between neutral and the
terminal in the starter socket that is connected to
the filament that is connected to the ballast. If the
meter reads open, the ballast, the light socket, or
the wiring between them is defective. If the meter
reads around 22 ohms replace the starter. If the
meter reads zero the ballast is shorted or a wire is
pinched to chassis.
120 volt outlet:
Some model ranges sold in Canada are equipped with a
120 volt convenience outlet. To protect the wiring in the
range from products being plugged into this outlet, a 15
amp fuse is installed in the circuit before the outlet. If
voltage is not present at the outlet check the fuse and
the outlet.
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