EPP-400 - ESAB Welding &

EPP-400
Plasma Power Source
Instruction Manual
0558005805
Be sure this information reaches the operator.
You can get extra copies through your supplier.
caution
These INSTRUCTIONS are for experienced operators. If you are not fully familiar with the
principles of operation and safe practices for arc welding and cutting equipment, we urge
you to read our booklet, “Precautions and Safe Practices for Arc Welding, Cutting, and
Gouging,” Form 52-529. Do NOT permit untrained persons to install, operate, or maintain
this equipment. Do NOT attempt to install or operate this equipment until you have read
and fully understand these instructions. If you do not fully understand these instructions,
contact your supplier for further information. Be sure to read the Safety Precautions before installing or operating this equipment.
USER RESPONSIBILITY
This equipment will perform in conformity with the description thereof contained in this manual and accompanying labels and/or inserts when installed, operated, maintained and repaired in accordance with the instructions provided. This equipment must be checked periodically. Malfunctioning or poorly maintained equipment
should not be used. Parts that are broken, missing, worn, distorted or contaminated should be replaced immediately. Should such repair or replacement become necessary, the manufacturer recommends that a telephone
or written request for service advice be made to the Authorized Distributor from whom it was purchased.
This equipment or any of its parts should not be altered without the prior written approval of the manufacturer.
The user of this equipment shall have the sole responsibility for any malfunction which results from improper
use, faulty maintenance, damage, improper repair or alteration by anyone other than the manufacturer or a service facility designated by the manufacturer.
table of contents
Section / Title
Page
1.0 Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
2.0
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2 General Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.3 Dimensions and Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
95
95
95
96
3.0
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
3.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
3.2 Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
3.3 Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
3.4 Input Power Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
3.4.1 Primary Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
3.4.2 Input Conductors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
3.4.3 Input Connection Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
3.5 Output Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
3.5.1 Output Cables (customer supplied) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
3.5.2 Output Connection Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
3.6 Parallel Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
3.7 CNC Interface Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
4.0
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
4.1 Block Diagram Circuit Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
4.2 Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
4.2.1 Modes of Operation: Cutting and Marking Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
4.3 Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
4.4 Arc Initiation Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
4.4.1 Enable / Disable Arc Initiation Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
4.4.2 Adjust Arc Initiation Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
4.4.3 Arc Initiation Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
4.4.4 Start Current and Up-Slope Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
4.5 EPP-400 V-I Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
5.0
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
5.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
5.2 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
5.3 Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
table of contents
Section / Title
6.0
Page
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
6.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
6.2 Fault Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
6.3 Fault Isolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
6.3.1 Fans Not Working . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
6.3.2 Power Not On or Low Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
6.3.3 Fault Light Illumination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
6.3.4 Torch Will Not Fire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295
6.3.5 Fuses F1 and F2 Blown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
6.3.6 Intermittent, Interrupted or Partial Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
6.4 Testing and Replacing Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298
6.4.1 Power Rectifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
6.4.2 Troubleshooting Freewheeling Diode and IGBTs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
6.4.3 Power Shunt Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303
6.4.4 Procedure for Verifying Calibration of Digital Meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
6.5 Control Circuit Interface Using J1 and J6 Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
6.6 Auxiliary Main Contactor (K3) and Solid State Contactor Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
6.7 Main Contactor (K1A, K1B and K1C) Activation Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
6.8 Arc Current Detector Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309
6.9 Current Control Pot and Remote Vref . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
6.10 Pilot Arc HI / LO and Cut / Mark Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
6.11 Current Transducer for Optional Output Current Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312
7.0 Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
7.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
7.2 Ordering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
92
SECTION 1
1.0
SAFETY PRECAUTIONS
Safety Precautions
Users of ESAB welding and plasma cutting equipment have the ultimate responsibility for ensuring that anyone
who works on or near the equipment observes all the relevant safety precautions. Safety precautions must meet
the requirements that apply to this type of welding or plasma cutting equipment. The following recommendations
should be observed in addition to the standard regulations that apply to the workplace.
All work must be carried out by trained personnel well acquainted with the operation of the welding or plasma
cutting equipment. Incorrect operation of the equipment may lead to hazardous situations which can result in
injury to the operator and damage to the equipment.
1. Anyone who uses welding or plasma cutting equipment must be familiar with:
- its operation
- location of emergency stops
- its function
- relevant safety precautions
- welding and / or plasma cutting
2. The operator must ensure that:
- no unauthorized person stationed within the working area of the equipment when it is started up.
- no one is unprotected when the arc is struck.
3. The workplace must:
- be suitable for the purpose
- be free from drafts
4. Personal safety equipment:
- Always wear recommended personal safety equipment, such as safety glasses, flame proof
clothing, safety gloves.
- Do not wear loose fitting items, such as scarves, bracelets, rings, etc., which could become
trapped or cause burns.
5. General precautions:
- Make sure the return cable is connected securely.
- Work on high voltage equipment may only be carried out by a qualified electrician.
- Appropriate fire extinquishing equipment must be clearly marked and close at hand.
- Lubrication and maintenance must not be carried out on the equipment during operation.
SECTION 1
WARNING
SAFETY PRECAUTIONS
WELDING AND PLASMA CUTTING CAN BE INJURIOUS TO YOURSELF AND
OTHERS. TAKE PRECAUTIONS WHEN WELDING OR CUTTING. ASK FOR
YOUR EMPLOYER’S SAFETY PRACTICES WHICH SHOULD BE BASED ON
MANUFACTURERS’ HAZARD DATA.
ELECTRIC SHOCK - Can kill.
- Install and earth (ground) the welding or plasma cutting unit in accordance with applicable standards.
- Do not touch live electrical parts or electrodes with bare skin, wet gloves or wet clothing.
- Insulate yourself from earth and the workpiece.
- Ensure your working stance is safe.
FUMES AND GASES - Can be dangerous to health.
- Keep your head out of the fumes.
- Use ventilation, extraction at the arc, or both, to take fumes and gases away from your breathing zone
and the general area.
ARC RAYS - Can injure eyes and burn skin.
- Protect your eyes and body. Use the correct welding / plasma cutting screen and filter lens and wear
protective clothing.
- Protect bystanders with suitable screens or curtains.
FIRE HAZARD
- Sparks (spatter) can cause fire. Make sure therefore that there are no inflammable materials nearby.
NOISE - Excessive noise can damage hearing.
- Protect your ears. Use earmuffs or other hearing protection.
- Warn bystanders of the risk.
MALFUNCTION - Call for expert assistance in the event of malfunction.
READ AND UNDERSTAND THE INSTRUCTION MANUAL BEFORE INSTALLING OR OPERATING.
PROTECT YOURSELF AND OTHERS!
section 2description
2.1 Introduction
The EPP power source is designed for high speed plasma mechanized cutting applications. It can be used with
other ESAB products such as the PT-15 and PT-600 torches along with the Smart Flow II, a computerized gas
regulation and switching system.
•
•
•
•
•
•
•
•
50 to 400 amperes cutting current range
Forced air cooled
Solid state DC power
Input voltage protection
Local or remote front panel control
Thermal switch protection for main transformer and power semiconductor components
Top lifting rings or base forklift clearance for transport
Parallel secondary power source capabilities to extend current output range.
2.2 General Specifications
Part Number
EPP-400 400V,
50/60Hz CE
EPP-400 460V,
60Hz
EPP-400 575V,
60Hz
0558005614
0558005615
0558005616
Voltage
200 VDC
Current range DC (marking)
Output
Current range DC (cutting)
(100 % duty cycle)
Power
50A to 400A
12A to 400A
80 KW
* Open Circuit Voltage (OCV)
Input
410 VDC
427 VDC
427 VDC
Voltage (3-phase)
400 V
460 V
575 V
Current (3- phase)
138A RMS
120A RMS
96A RMS
Frequency
50/60 HZ
60 Hz
60 Hz
KVA
95.6 KVA
95.6 KVA
95.6 KVA
Power
87 KW
87 KW
87 KW
Power Factor
91.0 %
91.0%
91.0%
Input Fuse Rec.
200A
150A
125A
* Open circuit voltage is reduced to 290V in the marking mode.
95
section 2description
2.3 Dimensions and Weight
114.3 mm
45.00”
94.6 mm
37.25”
102.2 mm
40.25”
Weight = 925.34 kg. (2040 lbs.)
96
section 3installation
3.1 General
WARNING
Failure To Follow Instructions Could Lead To Death, Injury Or Damaged Property. Follow these instructions to
prevent injury or property damage. You must comply with
local, state and national electrical and safety codes.
3.2 Unpacking
caution
•
•
•
Using one lifting eye will damage sheet metal and frame.
Use both lifting eyes when transporting with overhead method.
Unit weighs over 907 kg. (2000 lbs.) Use approved straps or cables in
good condition.
Inspect for transit damage immediately upon receipt.
Remove all components from shipping container and check for loose parts in container.
Inspect louvers for air obstructions.
3.3 Placement
Note:
Use both lifting eyes when transporting from overhead.
•
•
•
•
•
A minimum of 0.61 M (2 ft.) clearance on front and back for cooling air flow.
Plan for top panel and side panels having to be removed for maintenance, cleaning and inspection.
Locate the EPP-400 relatively close to a properly fused electrical power supply.
Keep area beneath power source clear for cooling air flow.
Environment should be relatively free of dust, fumes and excessive heat. These factors will affect cooling efficiency.
caution
Conductive dust and dirt inside power source may cause arc flashover.
Equipment damage may occur. Electrical shorting may occur if dust is
allowed to build-up inside power source. See maintenance section.
97
section 3installation
3.4 Input Power Connection
Electric Shock Can Kill!
Provide maximum protection against electrical shock.
Before any connections are made inside the machine, open
the line wall disconnect switch to turn power off.
WARNING
3.4.1 Primary Power
EPP-400 is a 3-phase unit. Input power must be provided from a line (wall) disconnect switch that contains fuses
or circuit breakers in accordance to local or state regulations.
Recommended input conductor and line fuse sizes:
Input at Rated Load
Volts
Amperes
Input and Ground
conductor* CU/
mm2 (AWG)
Time delay
Fuse size
(amperes)
400
138
95 (4/0)
200
460
120
95 (3/0)
150
575
96
50 (1/0)
125
Rated load is output of 400A at 200V
* Sizes per National Electrical Code for a 90° C (194˚ F) rated copper conductors @ 40° C (104˚ F) ambient. Not more
than three conductors in raceway or cable. Local codes should be followed if they specify sizes other than those listed
above.
To estimate the input current for a wide range of output conditions, use the formula below.
Input current =
NOTICE
(V arc) x (I arc) x 0.688
(V line)
Dedicated power line may be necessary.
EPP-400 is equipped with line voltage compensation but to avoid
impaired performance due to an overloaded circuit, a dedicated
power line may be required.
98
section 3installation
3.4.2 Input Conductors
•
•
•
Customer supplied
May consist either of heavy rubber covered copper conductors (three power and one ground) or run
in solid or flexible conduit.
Sized according to the chart.
Input conductors must be terminated with ring terminals.
Input conductors must be terminated with ring terminals sized for
12.7 mm (0.50”) hardware before being attached to the EPP-400.
NOTICE
3.4.3 Input Connection Procedure
1
1. Remove left side panel of the EPP-400
2. Thread cables through the access opening in the rear panel.
3. Secure cables with a strain relief or conduit coupling (not supplied) at the access opening.
4. Connect the ground lead to the stud on the chassis base.
5. Connect the power lead ring terminals to the primary terminals with supplied bolts, washers and nuts.
6. Connect the input conductors to the line (wall) disconnect.
2
3
1 = Primary Terminals
2 = Chassis Ground
3 = Power Input Cable Access Opening (Rear Panel)
99
section 3installation
WARNING
Electric Shock Can Kill!
Ring terminals must have clearance between side panel
and main transformer. Clearance must be sufficient to
prevent possible arcing. Make sure cables do not interfere with cooling fan rotation.
WARNING
Improper Grounding Can Result In Death or Injury.
Chassis must be connected to an approved electrical
ground. Be sure ground lead is NOT connected to any primary terminal.
3.5 Output Connections
WARNING
Electric Shock Can Kill! Dangerous Voltage And Current!
Any time working around a plasma power source with covers removed:
•
DISCONNECT POWER SOURCE AT THE LINE (WALL) DISCONNECT.
•
HAVE A QUALIFIED PERSON CHECK THE OUTPUT BUS BARS (POSITIVE AND NEGATIVE) WITH A VOLTMETER.
3.5.1 Output Cables (customer supplied)
Choose plasma cutting output cables (customer supplied) on the basis of one 4/0 AWG, 600 volt insulated copper cable for each 400 amps of output current.
Note:
Do not use 100 volt insulated welding cable.
100
section 3installation
3.5.2 Output Connection Procedure
1. Remove access panel on the lower front of the power source.
2. Thread output cables through the openings at the bottom of the front panel or at the bottom of the power source immediately behind the front panel.
3. Connect cables to designated terminals mounted inside the power source using UL listed pressure wire connectors.
4. Replace panel removed during the first step.
Two 400 power sources may be connected together to extend the output current range.
Access Panel
3.6 Parallel Installation
caution
Parallel power source start currents exceed recommended amounts
when cutting below 100A.
Use only one power source for currents below 100A.
We recommend disconnecting the negative lead from the secondary power source when changing to currents below 100A. This lead
should be safely terminated to protect against electric shock.
101
section 3installation
Note:
Primary power source has the electrode (-) conductor jumpered. The secondary power source has the
work (+) jumpered.
1.
2.
3.
4.
Connect the negative (-) output cables to the arc starter box (high frequency generator).
Connect the positive (+) output cables to the workpiece.
Connect the positive (+) and negative (-) conductors between the power sources.
Connect the pilot arc cable to the pilot arc terminal in the primary power source. The pilot arc connection in the secondary power source is not used. The pilot arc circuit is not run in parallel.
5. Set the Pilot Arc HIGH / LOW switch on the secondary power source to “LOW”.
6. Set the Pilot Arc HIGH / LOW switch on the primary power source to “HIGH”.
7. If a remote 0.00 to +10.00 VDC current reference signal is used to set the output current, feed the same signal into both
power sources. Connect J1-A (common) of both power sources together and connect J1-B (0.00 - 10.00 VDC) of both
power sources together. With both power sources operating, the output current can be predicted using the following
formula: [output current (amps)] = [reference voltage] x [100]
Connections for parallel installation of two EPP-400 power sources
EPP-400
Secondary Power
Source
electrode
work
(-)
(+)
EPP-400
Primary Power
Source
work
(+)
pilot arc
1 - 14 AWG 600V
lead to pilot arc connection in arc starter
box (h.f. generator)
2 - 4/0 600V
positive leads
to workpiece
102
electrode
(-)
2 - 4/0 600V
negative leads
in arc starter box
(h.f. generator)
section 3installation
Electric Shock Can Kill!
Exposed Electrical Conductors Can Be Hazardous!
Do not leave electrically “hot“ conductors exposed. When
disconnecting the secondary power source from the primary, verify the correct cables were disconnected. Insulate the disconnected ends.
WARNING
When using only one power source in a parallel configuration, the negative electrode conductor must be disconnected from the secondary power source and the plumbing
box. Failure to do this will leave the secondary electrically “hot”.
The EPP-400 does not have an ON/OFF switch. The main power is controlled through the line (wall) disconnect switch.
Do not operate the EPP-400 with Covers Removed.
High voltage components are exposed increasing shock
hazard.
Internal component may be damaged because cooling
fans will lose efficiency.
WARNING
EPP-400
EPP-400
Secondary Power
Source
Primary Power
Source
work
2 - 4/0 600V
positive leads
to workpiece
electrode
work
Disconnect negative
connection from secondary power source
and insulate to convert from two to one
power source
103
electrode
2 - 4/0 600V
negative leads
in arc starter box
(h.f. generator)
section 3installation
3.7 CNC Interface Cables
B
A
A - 0558005528 Interface Cable Connection
Connection from 10 pin Plug J6 to CNC interface connector.
B - 0558005530 Interface Cable Connection
Connection from 19 pin Plug J1 to CNC interface connector.
Note:
Interface cables are NOT supplied with the EPP400 Power Supply and are provided as reference
information only.
104
(Slave)
T1 Main
Transformer
105
CNC Common
(Floating)
S
T
Galvanic
Isolator
T
Right
IGBT Modules
Twisted Pair
Left
IGBT Modules
T
L1
WORK
NOZZLE
ELECTRODE
Precision
Shunt
Pilot Arc
Circuit
R (snub)
Biased Snubber
250V Peak
T1
Blocking Diodes
R (boost)
Boost Starting
Circuit
425V Peak
T1
Blocking Diodes
Contact on Pilot
Arc Contactor
Right Hall
Sensor
L2
Free Wheeling
Diodes
Left Hall
Sensor
EPP-400
BLOCK DIAGRAM
“T” Common Connected to Earth Grounded Work Through the “+” Output
Error Amplifiers
Feedback For Fast Inner Servos
Control Circuit
Bus Rectifiers
300U120’s
Cap.
Bank
Feedback for Constant
Current Servo
Gate
Drive
Sync Signal
For Alternate
Switching
Gate
Drive
-310V DC Bus
PWM
PWM
4.1 Block Diagram Circuit Description
0.0 - 10.0V DC Vref
Iout = (Vref) x (50)
3 Phase
Input
H
Galvanic
Isolator
Right PWM / Gate Drive Board
2
(Master)
Galvanic
Isolator
Left PWM / Gate Drive Board
section 4
operation
section 4
operation
4.1 Block Diagram Circuit Description (con’t.)
The power circuit utilized in the EPP-400 is commonly referred to as a Buck Converter or a Chopper. High speed electronic
switches turn on and off several thousand times per second providing pulses of power to the output. A filter circuit, consisting primarily of an inductor (sometimes called a choke), converts the pulses to a relatively constant DC (Direct Current)
output.
Although the filter inductor removes most of the fluctuations from the “chopped” output of the electronic switches, some
small fluctuations of output, called ripple, remain. The EPP-400 utilizes a patented power circuit combining the output
of two choppers, each providing approximately half the total output, in a manner that reduces ripple. The choppers are
synchronized so that when the ripple from the first chopper is increasing output, the second chopper is decreasing output.
The result is the ripple from each chopper partially cancels the ripple from the other. The result is ultra low ripple with a
very smooth and stable output. Low ripple is highly desirable because torch consumable life is often improved with low
ripple.
The graph below shows the effect of ESAB’s patented ripple reduction using two choppers synchronized and switching
alternately. Compared to two choppers switching in unison, the alternate switching typically reduces ripple a factor of 4
to 10.
EPP-400 Output RMS Ripple Current Versus Output Voltage
Choppers Synchronized and Switching in Unison (10KHz Ripple)
7.0
RMS Ripple Current (Amperes)
6.0
5.0
4.0
3.0
Patented EPP-400
Choppers Synchronized and Switching
Alternately (20KHz Ripple)
2.0
1.0
0.0
0
50
100
150
Output Voltage (Volts)
106
200
250
300
section 4
operation
4.1 Block Diagram Circuit Description (con’t.)
The EPP-400 Block Diagram (after Subsection 6.4.4) shows the main functional elements of the power source. T1, the Main
Transformer, provides isolation from the primary power line as well as the proper voltage for the 310V DC Bus. The Bus Rectifiers convert the three phase output of T1 to the 310V bus voltage. A capacitor bank provides filtering and energy storage
that supplies power to the high speed electronic switches. The switches are IGBT’s (Insulated Gate Bipolar Transistors). The
310V bus provides power for both the Left (Master) Chopper and the Right (Slave) Chopper.
Each chopper contains IGBT’s, Free Wheeling Diodes, a Hall Sensor, a Filter Inductor, and Blocking Diodes. The IGBT’s are
the electronic switches that, in the EPP-400, turn on and off 10,000 times per second. They provide the pulses of power
filtered by the inductor. The Free Wheeling Diodes provide the path for current to flow when the IGBT’s are off. The Hall
Sensor is a current transducer that monitors the output current and provides the feedback signal for the control circuit.
The Blocking Diodes provide two functions. First, they prevent the 425V DC from the Boost Starting Circuit from feeding
back to the IGBT’s and the 310V Bus. Second, they provide isolation of the two choppers from one another. This permits
independent operation of each chopper without the other chopper functioning.
The Control Circuit contains regulating servos for both choppers. It also contains a third servo that monitors the total
output current signal fed back from the Precision Shunt. This third servo adjusts the two chopper servos to maintain an
accurately controlled output current commanded by the Vref signal.
The Vref circuitry is galvanically isolated from the rest of the power source. The isolation prevents problems that can arise
from “ground” loops.
Each chopper, the Left Master, and the Right Slave, contain their own PWM / Gate Drive PC Boards mounted directly on the
IGBT’s. This circuitry provides the on / off PWM (Pulse Width Modulation) signals to drive the IGBT’s. The Left (Master) PWM
provides a synchronized clock signal to its own Gate Drive circuitry as well as to the Right (Slave) Gate Drive circuitry. It is
through this synchronized signal that the IGBT’s from the two sides switch alternately reducing output ripple.
The EPP-400 contains a Boost Supply for providing approximately 425V DC for arc starting. After the cutting arc is established, the Boost Supply is turned off with a contact on the Pilot Arc Contactor (K4).
A Biased Snubber reduces the voltage transients created during cutting arc termination. It also reduces the transient voltages from a parallel power source thus preventing damage to the power source.
The Pilot Arc Circuit consists of the necessary components for establishing a pilot arc. This circuit disengages when the
cutting arc is established.
107
section 4
operation
4.2 Control Panel
H
I
J
F
G
A
C
B
D
E
K
L
A - Main Power
Indicator illuminates when input power is applied to the power source.
B - Contactor On
Indicator illuminates when the main contactor is energized.
C - Over Temp
Indicator illuminates when power source has overheated.
D - Fault
Indicator illuminates when there are abnormalities in the cutting process or
when the input line voltage falls outside of the required nominal value by
±10%.
E - Power Reset Fault
Indicator illuminates when a serious fault is detected. Input power must be
disconnected for at least 5 seconds and then reapplied.
F - Current Dial (Potentiometer)
EPP-400 dial shown. EPP-400 has a range of 12 to 600 A. Used only in panel
mode.
108
section 4
operation
4.2 Control Panel (con’t.)
G - Panel Remote Switch
Controls the location of current control.
•
•
Place in the PANEL position for control using the current potentiometer.
Place in REMOTE position for control from an external signal
(CNC).
H and L - Remote Connection
Amphenol 19 pin plug (J1) and 10 pin plug (J6) for connecting power source
to CNC.
I - Pilot Arc HIGH / LOW Switch
Used to select amount of pilot arc current desired. As a general rule, for 100
amperes and below, a setting of LOW is used. This can vary depending on
gas, material and torch used. High/Low settings are specified in cutting data
included in the torch manual. When the EPP-400 is set to marking mode, this
switch must be in the low position.
I
J
H
F
G
A
C
B
D
E
K
L
109
section 4
operation
4.2 Control Panel (con’t.)
J - Meters
Displays voltage and amperage when cutting. The ammeter can be activated
when not cutting to view an estimation of the cutting current before cutting
begins.
K - Actual/Preset Switch
The ACTUAL AMPS / PRESET AMPS spring return toggle switch, S42, defaults
to the ACTUAL (UP) position. In the ACTUAL position, the OUTPUT AMMETER
displays the output cutting current.
In the PRESET (DOWN) position, the OUTPUT AMMETER displays an estimate
of the output cutting current by monitoring the 0.00 – 10.00 VDC cutting current reference signal (Vref ). The reference signal comes from the CURRENT
POTENTIOMETER with the PANEL/REMOTE switch in the PANEL (UP) position
and from a remote reference signal (J1-A / J1-B(+)) with the PANEL/REMOTE
switch in the REMOTE (DOWN) position. The value displayed on the OUTPUT
AMMETER will be the value of Vref (volts) times 50. For example, a reference
signal of 4.00V will result in a preset reading of 200 Amps on the meter.
The switch may be changed to and from the ACTUAL and PRESET positions
at any time without affecting the cutting process.
WARNING
Dangerous Voltages and Current!
Electric Shock Can Kill!
Before operation, ensure installation and grounding procedures have been followed. Do not operate this equipment with covers removed.
110
section 4
operation
4.2.1 Modes of Operation: Cutting and Marking Mode
1.
The EPP-400 operates in the Cutting Mode through a single continuously adjustable output current range from 50A
through 400A using either the Current Potentiometer, on the front panel, or a remote current reference signal fed into
connector, J1.
When using a remote signal, 50A corresponds to a current reference signal of 1.00VDC, and 400A corresponds to a
signal of 8.00VDC. For signals over 8.00V, the power source internally limits the output current to a typical value of
425A.
The EPP-400 defaults to the Cutting Mode of operation unless the command signal for Marking Mode is supplied.
2.
The power source is placed in Marking Mode with an external isolated relay or switch contact connecting J1-F (115VAC)
to J6-A. See Schematic Diagram included inside back cover. This contact closure must be made before (50mS or longer) issuing a Start or Contactor On command.
In the Marking Mode, the output current is adjusted through a single continuously adjustable range from 12A through
400A using either the Current Potentiometer, on the front panel, or a remote current reference signal fed into connector, J1.
When using a remote signal, 12A corresponds to a current reference signal of 0.24VDC, and 400A corresponds to a
signal of 8.00VDC. For signals over 8.00V, the power source internally limits the output current to a typical value of
425A.
In the Marking Mode, the Boost Supply, used for arc starting in the Cutting Mode, is de-activated. The resulting Open
Circuit Voltage is approximately 290V at nominal input line voltage. Additionally, K12 closes connecting R60 through
R67 into the output circuit. These resistors help stabilize the output for the low marking currents. The power source
is capable of its full 400A 100% duty output in the marking mode.
In the Marking Mode, the factory set Minimum Starting Current of 43 Amps must be reduced to 6 Amps by changing
the settings of Switch Two (SW2) on the Control PC Board mounted behind the access cover on the upper right of the
front panel. SW2 positions 5, 6, and 7 should be off (down), and position 8 should be on (up).
111
section 4
operation
4.3 Sequence of Operation
4.3 Sequence of Operation
1.
Apply power by closing the line (wall) switch. (The EPP-400
does not have an on / off switch). The main power light will
illuminate and the fault light will flash and then go out.
2.
Select the Panel / Remote setting.
3.
Set pilot arc High / Low switch. (Refer to cutting data in the
torch manual.)
REMOTE
4.
If using panel mode, view preset amps with the ACTUAL /
PRESET AMPS switch. Adjust current until the approximate
desired value is shown on the ammeter.
HIGH
5.
Begin plasma cutting operation. This may include manually
setting up other options, depending on the total plasma
package.
LOW
6.
If using panel mode, after cutting has begun, adjust current
to desired amount.
7.
Check for fault light. If a fault light illuminates, refer to troubleshooting section.
Apply Power
PANEL
PILOT
ARC
ACTUAL AMPS
Note:
PRESET AMPS
Begin
Cutting
The fault light flashes when the contactor is first
turned on signifying the DC Bus powered up normally.
112
section 4
operation
4.4 Arc Initiation Settings
The time to achieve full current can be adjusted for a soft start. This feature uses a reduced current to start and then gradually ramps up to full current. The EPP-400 is factory shipped with soft start enabled. The default settings are:
Minimum Start Current . . . . . . . . . . . . . 43A
Start Current . . . . . . . . . . . . . . . . . . . . . . . 50% of cut current
Timing to achieve full current . . . . . . . 800 msec
Dwell Time . . . . . . . . . . . . . . . . . . . . . . . . . 50 msec
These timing functions can be disabled or adjusted to suit individual system requirements.
Start Current Wave Form With Soft Start ON
Cut Current
1OUT = 50 VREF
DC Output Current
DC Output Current
Start Current Wave Form With Soft Start OFF
Approx. 2 msec time to full current
Time
WARNING
Cut Current
1OUT = 50 VREF
Start Current
Dwell
Time
Time to full current
800 msec
Time
Electric Shock Can Kill!
Shut off power at the line (wall) disconnect before removing any covers or making any adjustments to the
power source.
113
section 4
operation
4.4.1 Enable/Disable Arc Initiation Conditions
Factory default setting shown.
1
2
3
4
51
62
73
84
5
6
7
8
on
off
SW2
SW1
SW2
1. Remove access panel on the upper-right corner of the front panel. Be sure to replace this panel after adjustments have
been made.
2. Locate SW1 and PCB1 and push both rocker switches down to disable. To enable push both switches up. (If one switch
is up and the other is down, arc initiation time is considered on.)
4.4.2 Adjusting Arc Initiation Timer
Factory default settings shown
1
2
3
4
5
6
7
8
on
off
SW2
Minimum Start Current
Controlled by selection of positions 5 through 8 of SW2. When a switch is pushed on, its value is added to the factory set
minimum value of 3A.
Switch #5 = 25A min. start current
Switch #6 = 12A min. start current
Switch #7 = 6A min. start current
Switch #8 = 3A min. start current
Default setting is with 5, 6 and 8 on 3A + 25A + 12A + 3A = 43A
Dwell Time
Controlled by selections of positions 1 through 4 of SW2 on PCB1. When a switch is pushed on, its value is added to the
minimum dwell time of 10 msec.
Switch #1 = 10 msec dwell time
Switch #2 = 20 msec dwell time
Switch #3 = 40 msec dwell time
Switch #4 = 80 msec dwell time
The default setting is with switch #3 on. 40 msec + 10 msec (minimum) = 50 msec
114
section 4
operation
4.4.3 Arc Initiation Controls
Start Current Potentiometer
UP-Slope Timer
SW1
SW2
4.4.4 Start Current and Up-Slope Timer
Starting Current (%) and Pot Setting Relationship
Start Current
Set using potentiometer located above and to the left of center
of PCB1. Factory default setting of 7 results in a starting current
that is 50% of the cutting current..
Percentage (%) of Cutting Current
90%
80%
70%
60%
Up-Slope Timer
Three position switch located next to the start current potentiometer. Time is from start current (after dwell ends) to full
current. Factory default = 800 msec.
50%
40%
30%
Left position = 250 msec
Center position = 800 msec
Right Position = 1200 msec
20%
10%
0%
0
1
2
3
4
5
6
Start Current Pot Setting
7
8
9
10
MAX
115
38
section 4
operation
4.5 EPP-400 V-I Curves
EPP-400 V-I CURVES
= (50) xx (V
( VREF
)
IIOUT
OUT
REF )
427 v Open Circuit (460 & 575 v Models)
410 v Open Circuit (400 v Model)
400
Output of Boost/Start Circuit (off in marking mode)
V REF = 8.000
Max. Current Rating
Internal Current Limit
V REF = 6.000
V REF = 4.000
100
Min. Cutting Current
V REF = 2.000
200
Min. Marking Current
V REF = 1.000
300
V REF = 0.240
Output Voltage (volts)
Max. Output Voltage
@Nominal Line
0
0
100
200
300
Output Current (Amperes)
116
400
500
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