Tweco PAK 200i - Manual (Page 120)

PAK 200i
A-40 APPENDIX Manual 0-5335
Appendix 17: Advanced Troubleshooting
How to use this guide.
This guide starts with a general description of the systems and differences between the different versions. One
should become familiar with this before starting to troubleshoot.
To resolve a problem first refer to the CCM Status Code tables in Operation section. These include brief listing of
possible causes. If your problem is not resolved there then come here for more detailed troubleshooting. Find the
section for the code you are experiencing and proceed step by step.
This is a generic troubleshooting guide intended to cover several different XT and XT based models. Your particular
model may not include some of the accessories mentioned. For example a Pak �00i or a AC �00 XT do not use either
of the separate gas controls (GCM �010 or DFC 3000). Also different torches are used with different models. ignore
or skip over those references to items that are not part of your unit.
System Overview
The Auto-Cut 200 & 300 XT, Ultra-Cut 100, 200, 300 & 400 XT and Pak 200 XT power supplies include one, two or
three inverter modules (IM). Each IM may have either 1 or 2 inverter sections designated A or B sections. The IMs
are mounted one over the other numbered from bottom to top. The sections are also designated from bottom to
top with section A being on the bottom of each module. An IM with one section is considered to be a ½ or “partial”
module with the upper or “B” section missing. ½ modules are used with the 200A & 300A power supplies and will
always be in the middle position. IMs with 2 sections are considered to be “full” modules.
Each inverter section can supply up to 67A but does not do so in all configurations:
A 400A unit uses 6 sections. 400A / 6 = 66.67A per section.
A 300A unit uses 5 sections. 300A / 5 = 60A per section.
A 200A unit uses 3 sections. 200/3 = 66.67A per section.
A 100A unit uses 2 sections. 100/2=50A per section.
Unit configurations.
With the exception of the AC 200 XT and Pak 200 XT all other units have the same chassis with room for up to 3
IMs. The unused areas have blank panels filling the empty locations which are required for proper air flow. A 100A
system uses 1 full IM; 200A uses 1 and ½ modules with a full module in the bottom location and a ½ module in the
middle position. A 300A unit has full modules top and bottom with the ½ module in the middle location. The AC
200 XT and Pak 200 XT have only the bottom and middle locations for IMs. An internal Arc Starter and Gas Control
are located in the place of the 3rd or upper IM.
Inverter module cooling.
The power semiconductors of the inverter modules are liquid cooled allowing us to get more power in a smaller
area and at lower cost. Each IM has a liquid cooled heatsink or “cold plate” shared by the 2 inverter sections. The
magnetic components, transformers and inductors, are air cooled and mounted on the back side of the IMs where
they are exposed to high volumes of air flow from the cooling fans whose air also cools liquid coolant in the radia-
tor or heat exchanger. It is important that lower right side panel be in place or the air flow will not be proper for
cooling the magnetics.
Inverter control.
The inverter sections are operated as separate inverters whose outputs are connected in parallel. They are con-
trolled independently from the Command and Control Module (CCM) which is the “brains” of the system. Each
inverter section has a separate ribbon cable connected to it coming from the CCM which has 6 connectors, J31 – J36
corresponding to the inverter sections 1A through 3B. The ribbon cables are labeled on the inverter ends as INV
with the number and section (INV 1A, INV 1B, etc.). A 100A unit will only have ribbon cables in J31 & J32; a 200A
will have J31-J33 filled with the others empty. 300A will have J34 missing with the others filled.
Other boards in the system include the System Bias Supply, the Relay & Interface PCB, Display PCB, Pilot PCB
and AC Suppression PCB. The CCM has 2 boards, the I/O (input/output) and the CPU (central processing unit)
board. The CE units will also have one or more EMI Filter boards on the input power.