Tweco FP-55 - Manual (Page 30)

SERVICE 5-4 Manual 0-2846
3. Unit is overheated
a. Allow unit to cool down for at least 5 minutes.
Make sure the unit has not been operated be-
yond Duty Cycle limit. See Section 2 for duty
cycle specifications.
4. Input line voltage is below 75% of rated level
a. Check and connect to proper input power line.
5. Faulty components in unit
a. Return for repair or have qualified technician
repair per Service Manual.
C. Torch will not pilot when torch switch is activated
1. RUN/SET switch in SET position
a. Move switch to RUN position.
2. Faulty torch parts
a. Inspect torch parts and replace if necessary (re-
fer to Instruction Manual supplied with torch).
3. Gas pressure too high or too low
a. Set pressure to 70 psi (4.8 bar).
4. Faulty components in unit
a. Return for repair or have qualified technician
repair per Service Manual.
D. No cutting output; Torch switch activated; AC
Power indicator ON; Gas flowing; Fan operating
1. Torch not properly connected to power supply
a. Check that torch leads are properly attached to
power supply.
2. Shield cup not properly installed on torch
a. Check that shield cup is fully seated against torch
head. Refer to the torch manual for details.
3. Faulty components in unit
a. Return for repair or have qualified technician
repair per Service Manual.
4. Faulty Torch
a. Return for repair or have qualified technician
repair per Torch Manual.
E. Low cutting output
1. Incorrect setting of CURRENT control
a. Check and adjust to proper setting.
2. Faulty components in unit
a. Return for repair or have qualified technician
repair per Service Manual.
F. Limited output with no control
1. Poor input or output connections
a. Check all input and output connections.
2. Faulty components in unit
a. Return for repair or have qualified technician
repair per Service Manual.
G. Erratic or improper cutting output
1. Poor input or output connections
a. Check all input and output connections.
2. Poor ground or work connection is poor.
a. Check connection.
H. Arc shuts off during operation; Arc will not re-start
when torch switch is activated.
1. Unit is overheated (TEMP indicator ON)
a. Allow unit to cool down for at least 5 minutes.
Make sure the unit has not been operated be-
yond Duty Cycle limit. See Section 2 for duty
cycle specifications.
2. Fan blades blocked (TEMP indicator ON)
a. Check and clear blades.
3. Airflow obstructed (TEMP indicator ON)
a. Check for obstructed air flow around the unit
and correct condition.
4. Gas pressure too low (GAS indicator OFF when torch
switch is activated)
a. Check source for at 70 psi (4.8 bar); adjust as
needed.
5. Faulty components in unit
a. Return for repair or have qualified technician
repair per Service Manual.
I. No gas flow; AC POWER indicator ON; Fan
operating
1. Gas not connected or pressure too low
a. Check source for at least 70 psi (4.8 bar).
2. Gas supply pressure too high
a. Adjust to maximum 125 psi inlet pressure.
3. Shield Cup not properly installed.
a. Check to see that Control Circuit (PIP) pins are
installed. Refer to the torch manual for details.