Tweco 1000 CE Merlin - Manuel (Page 51)

Manual 0-2731 5-7 SERVICE
R. Start signal given to Power Supply. Gas flows for
selected pre-flow time then DC indicator is ON
steady. Pilot doesn't come on, but there is a spark
(repetitive snapping sound) from the spark gap in
Remote Arc Starter.
For the spark gap to fire, the Power Supply DC out-
put has to be getting to the Remote Arc Starter.
1. Consumable Torch parts are shorted
a. Check or replace the consumable Torch parts
2. Arcing or burning inside Torch Head Assembly
a. Remove the consumables from the Torch Head As-
sembly and check for signs of arcing or burning
inside the torch head. Replace Torch Head Assem-
bly if required.
3. Arcing or burning between the Torch fittings or from
the fittings to the Mounting Tube
a. Remove the Torch Head Assembly from the mount-
ing tube and check for arcing or burning between
the fittings or from the fittings to the tube. Repair as
required.
4. Defective CD transformer
a. Check for arcing around the CD Transformer (while
spark gap is firing) and look for any cracks in the
ferrite cores. If either problem exists replace the CD
Transformer.
S. Start signal given to Power Supply. Gas flows for
selected pre-flow time then DC indicator is ON
steady. Pilot doesn't come on and there is no
spark (no repetitive snapping sound) from the
spark gap in Remote Arc Starter.
1. Defective Remote Arc Starter PC Board.
a. Refer to Section 5.06 Test Procedures to isolate
the defective assembly.
5.06 Test Procedures For Optional
Remote Arc Starter
WARNING
High voltage may be present in the Arc Starter
Box.
The following two things are needed for the spark gap to fire in
the Arc Starter Box:
• 36 VAC bias voltage
The 36 VAC should be present anytime the Power Sup-
ply is turned ON. Refer to Appendix VI, 36 VAC Wiring
Block Diagram.
• Greater than 220 VDC Power Supply output
The Power Supply DC output should be greater
than 200 VDC when the Power Supply is activated
and the DC indicator is ON. The voltage will be
present across the torch tip (+) and electrode (-).
The following procedure is to isolate the faulty assembly to the
Remote Arc Starter PC Board, Power Supply, Torch, Torch Leads,
or Torch Supply Leads Assembly
1. Remove the START signal from the power Supply to dis-
able the DC high voltage from the Remote Arc Starter.
2. Place RUN/SET in SET position.
3. Power Supply DC indicator is OFF.
4. Remove cover from Remote Arc Starter.
5. On the Arc Starter PC Board locate the red indicator. When
the indicator is ON the 36 VAC between J1-1 and J1-3 on the
Logic PC Board is present to the Arc Starter PC Board.
NOTE
Connector J1 must be connected to the Arc Starter
PC Board.
• If red indicator is ON proceed to Step 15.
• If red indicator is OFF proceed to Step 6
6. Remove connector J1 from the Arc Starter PC Board
and reconnect making a good connection.
7. On the Arc Starter PC Board check the red indicator.
• If red indicator is ON proceed to Step 15.
• If red indicator is OFF proceed to Step 8
8. Remove connector J1 from the Arc Starter PC Board.