On/Off Power Switch Replacement; Fan Replacement; Diode Bridge Rectifier Replacement; Resistor Replacement - Firepower FP-18 Service Manual

4.9 ON/OFF Power Switch
Replacement
NOTE
When ordering a replacement ON/OFF Switch, or-
der the same Type and Color as is in your unit.
Switch
Dimensions
Type
5 prong 1"x2"
4 prong 1"x1-1/4"
Disconnect primary power to the system before dis-
assembling the torch, leads, or power supply.
1. Remove cover/handle from unit per subsection 4.2.
2. Note all wiring connections and locations to the
ON/OFF Switch.
3. Disconnect wires to ON/OFF Switch.
4. Push plastic clips down on top side of Switch and
slide Switch out by pulling it through front panel.
5. Install replacement ON/OFF Switch, by reversing
the above steps, keeping in mind the following:
a. Position wire connector L4 so that it runs along
side the Transformer, NOT across the top of the
Transformer.

4.10 Fan Replacement

1. Remove cover/handle from unit per subsection
4.2.
2. Carefully slide the Air Compressor out of the Trans-
former bracket and out of the way of the Fan. Be
careful not to strain wire connections. (If neces-
sary, remove Compressor completely, following
procedures described in subsection 4.5.)
3. For reference, mark wires with correct connection
designation, then disconnect two wires to Fan.
4. Remove two (2) rivets* securing Fan to the front
panel.
NOTE
*Some models may use screws instead of rivets.
5. Install replacement Fan. Refer to Figure 5.1 for
proper Fan orientation (or refer to the arrows
marked on the Fan chassis).
Service Manual 0-2692
Neon Catalog
Voltage
Color Number
red 115 9-0015
red 115 9-0021
WARNING
Proper fan orientation is essential to ensure proper
cooling of power supply parts.
6. Install Compressor by reversing steps 1-3, keeping
in mind the following:
a. Position wire connector L4 so that it runs along
side the Transformer, NOT across the top of the
Transformer or touching any metal parts.
b. The Compressor is secured in position by one
of the handle screws.
4.11 Diode Bridge Rectifier
Replacement
Refer to subsection 4.1, General Information, for
information about wire harnesses.
1. Remove cover/handle from unit per subsection 4.2.
2. Note all wire connections and locations to the Di-
ode Bridge Rectifier.
3. Disconnect wires to the Diode(s), and remove Di-
ode from unit.
4. Install replacement Diode, by reversing steps 1-3
above, noting the following:
a. Diode should be oriented with plus sign (+)
down and to the right.

4.12 Resistor Replacement

The FIREPOWER has two Resistors. The top Re-
sistor is 1K ohm and the bottom Resistor is .5 ohm.
These parts are not interchangeable. Be sure to
order the correct replacement part. To replace the
bottom Resistor, the top Resistor must be removed
first.
The Air Compressor must be removed (or option-
ally, pulled out of its frame and moved out of the
way) in order to remove the Resistor(s).
1. Remove cover/handle from unit per subsection 4.2.
2. Remove Air Compressor per subsection 4.5.
3. Note all wire connections and locations to the
Resistor(s).
17
NOTE
NOTE
NOTES
Firepower FP-18 Plasma Cutter