REHM SYNERGIC.ARC 251 User manual


SYNERGIC.ARC 251-504
MIG/MAG inert gas welding systems
OPERATING INSTRUCTIONS
REHM SCHWEISSTECHNIK
GB

Operating instructions
Operating instructions
MIG/MAG welding systems
SYNERGIC.ARC 251
SYNERGIC.ARC 311
SYNERGIC.ARC 351
SYNERGIC.ARC 304, 304 W, 304 S, 304 WS
SYNERGIC.ARC 404, 404 W, 404 S, 404 WS
SYNERGIC.ARC 504 W, 504 WS
REHM GmbH u. Co. KG
Ottostr. 2
D-73066 Uhingen, Germany
Phone: [phone]
Fax: [phone]
E-mail: [email protected]
Internet: www.rehm-online.de
Doc. No.: 7303208
Date of issue: 05.2023
REHM GmbH u. Co. KG, Uhingen, Germany 2023
The content of this description is the property of REHM GmbH u. Co. KG
The copying and distribution of this document, its use, and the communication of
its contents are strictly prohibited unless expressly authorized.
Offenders are liable to damages. All rights reserved in the event of patent, utility
model, or design patent.
No manufacture based on these documents is allowed.
Subject to change.
Name
Type
Manufacturer

List of contents
3
List of contents
1INTRODUCTION..............................................................................................................................6
1.1 Foreword.........................................................................................................................................6
1.2 General description .......................................................................................................................7
1.2.1 The principle of the inert gas metal welding process.......................................................................8
1.2.2 Intended use ....................................................................................................................................8
1.3 Symbols used.................................................................................................................................9
2SAFETY INSTRUCTIONS .............................................................................................................10
2.1 Warning symbols in these operating instructions ...................................................................10
2.2 Warning symbols on the system................................................................................................10
2.3 Notes and requirements ..............................................................................................................11
3UNIT DESCRIPTION .....................................................................................................................14
4FUNCTIONAL DESCRIPTION ......................................................................................................21
4.1 Overview of operating elements.................................................................................................21
4.2 Control panel description............................................................................................................22
4.2.1 Operating elements........................................................................................................................22
4.2.2 Operating elements........................................................................................................................23
4.3 Switching on.................................................................................................................................27
4.4 Peculiarities of the operating panel ...........................................................................................27
5CORNER MENU FUNCTIONS......................................................................................................28
5.1 Corner menu welding processes (top left) ................................................................................28
5.1.1 MSG ...............................................................................................................................................28
5.1.2 MSG manual ..................................................................................................................................28
5.1.3 MMA ...............................................................................................................................................28
5.1.3 Gouging..........................................................................................................................................28
5.2 Corner menu operating mode (top right)...................................................................................29
5.2.1 Two-cycle operating mode.............................................................................................................29
5.2.2 Two-cycle operating mode with slope-down..................................................................................30
5.2.3 Four-cycle operating mode ............................................................................................................31
5.2.4 Four-cycle operating mode with slope-down .................................................................................32
5.2.5 Spot ................................................................................................................................................33
5.2.6 Spot with slope-down .....................................................................................................................34
5.2.7 Two-cycle interval ..........................................................................................................................35
5.2.8 Two-cycle interval with slope-down ...............................................................................................36
5.2.9 Four-cycle interval..........................................................................................................................37
5.2.9 Four-cycle interval with slope-down...............................................................................................38
5.3 Characteristic curve corner menu..............................................................................................39
5.4 Welding process corner menu ...................................................................................................39
5.4.1 FOCUS.ARC ..................................................................................................................................39
5.4.2 POWER.ARC (MSG) .....................................................................................................................39
Infinitely variable operating panel description 5.5-5.9 ...................................................................................40
5.5 Welding current (A) display panel..............................................................................................40
5.6 Voltage (V) display panel.............................................................................................................40
5.7 LBL correction display panel......................................................................................................40

List of contents
4
5.8 Material thickness display panel ............................................................................................... 40
5.9 Wire feed speed display panel................................................................................................... 40
5.10 Characteristic curve info bar ..................................................................................................... 40
5.11 Switching level display panel .................................................................................................... 41
6. SUBMENUS.................................................................................................................................. 41
6.1 MSG parameters.......................................................................................................................... 41
6.1.1 Parameter settings ........................................................................................................................ 41
6.1.2 Setting the MSG welding parameters ........................................................................................... 41
6.1.3 Explanation of welding parameters ............................................................................................... 42
6.2 Language menu........................................................................................................................... 43
6.3 Saving and loading jobs............................................................................................................. 44
6.3.1 Save job ........................................................................................................................................ 44
6.3.2 Load job......................................................................................................................................... 44
6.4 Setup submenu ........................................................................................................................... 45
7CONTROL LAMPS ....................................................................................................................... 46
8OTHER FUNCTIONS.................................................................................................................... 47
8.1 Threading ..................................................................................................................................... 47
8.2 Gas test ........................................................................................................................................ 47
8.3 Water recirculation cooling........................................................................................................ 48
8.4 Temperature monitoring of the power units............................................................................. 48
8.5 External cooling of the power units .......................................................................................... 48
8.6 Fan and water pump control ...................................................................................................... 48
8.7 Polarity selection for self-protecting cored wires ................................................................... 48
9ACCESSORIES AND OPTIONS .................................................................................................. 49
9.1 Unit versions, accessories and options ................................................................................... 49
10 COMMISSIONING ........................................................................................................................ 52
10.1 Safety instructions ...................................................................................................................... 52
10.2 Working under elevated electrical risk in accordance with the regulations from IEC 974, EN
60 974-1, TRBS 2131 and BGR 500 Section 2.26 (previously VGB 15) (S) ............................ 52
10.3 Positioning the welding unit ...................................................................................................... 52
10.4 Connecting the welding unit ...................................................................................................... 54
10.5 Cooling the welding unit............................................................................................................. 54
10.6 Water cooling for MIG/MAG welding torches ........................................................................... 54
10.7 Connecting the welding cables ................................................................................................. 54
10.8 Connecting the torch .................................................................................................................. 54
10.9 Inserting the wire......................................................................................................................... 55
11 OPERATION ................................................................................................................................. 56
11.1 Safety instructions ...................................................................................................................... 56
11.2 Checks before switching on ...................................................................................................... 56

List of contents
5
11.3 Connecting the ground cable .....................................................................................................56
11.4 Serious risks during welding . ....................................................................................................57
11.5 Practical instructions for use .....................................................................................................59
12 FAULTS .........................................................................................................................................61
12.1 Safety instructions.......................................................................................................................61
12.2 Table of faults...............................................................................................................................61
12.3 Error messages ............................................................................................................................63
13 MAINTENANCE AND REPAIR .....................................................................................................64
13.1 Safety instructions.......................................................................................................................64
13.2 Maintenance table ........................................................................................................................65
13.3 Cleaning the inside of the unit....................................................................................................65
13.4 Cooling water check ....................................................................................................................66
13.5 Proper disposal ............................................................................................................................66
14 CIRCUIT DIAGRAMS ....................................................................................................................67
14.1 Components and spare parts .....................................................................................................71
15.1 Characteristic curve wire feeding unit.......................................................................................73
16 TECHNICAL DATA .......................................................................................................................78

Introduction
6
1 Introduction
1.1 Foreword
Dear Customer,
You have purchased an inert gas welding system from REHM, a renowned German
brand name.
We thank you for the confidence you have placed in our quality products.
Only components of the highest quality are used in SYNERGIC.ARC welding systems.
To allow long service life even under the toughest conditions, all REHM equipment is
manufactured using only parts that comply with our strict quality demands.
SYNERGIC.ARC welding systems have been developed and designed according to
the generally accepted rules for technology and safe operation. All relevant legal
regulations have been observed and complied with. Conformity is declared and is
marked with the CE symbol.
REHM welding systems are manufactured in Germany and therefore bear the "Made
in Germany" quality label.
REHM strives to immediately take advantage of technical progress and reserves the
right to adapt the design of the welding equipment at any time to the latest technical
requirements.
These operating instructions are for various SYNERGIC.ARC devices. Depending on
the type of machine purchased and its equipment and accessories, some functions
may not be available on it. Those functions are indicated in the relevant section.

Introduction
7
1.2 General description
Figure 1: SYNERGIC.ARC 504 WS
(Figure does not illustrate standard equipment)

Introduction
8
1.2.1 The principle of the inert gas metal welding process
With the inert gas metal welding process an electric arc burns between a melting wire
electrode and the workpiece. Argon, carbon dioxide (CO2) or a mixture of these or
other inert gasses are used.
The positive pole usually flows from the current contact tips to the wire electrode and
the negative pole is connected to the workpiece. An electric arc forms between the
wire electrode and the workpiece that melts both the wire electrode and the workpiece.
The wire electrode is therefore the conductor for the arc and weld filler material.
The wire electrode and the weld pool are protected against the influence of ambient
air by the inert gas, which flows continuously from the inert gas nozzle that is arranged
concentrically around the electrode.
1.2.2 Intended use
SYNERGIC.ARC welding systems may be used for MIG/MAG welding only.
REHM welding units are designed for welding various different metallic materials such
as unalloyed and alloyed steels, stainless steels, aluminium and CuSi3. Please also
observe the special rules that apply to your applications.
REHM welding machines are designed for use in both hand-held and machine-guided
operation.
REHM welding machines are, except when REHM expressly states otherwise in
writing, for sale to commercial/industrial users only and are intended to be used by
commercial/industrial users only. The machines may be operated only by persons
trained in the use and maintenance of welding equipment.
Welding power sources may not be installed in areas with increased electrical risk.
These operating instructions contain rules and guidelines for the intended use of your
system. Only compliance with these guidelines shall be considered as proper use.
Risks and damage incurred due to any other use is the responsibility of the operator.
Use under special requirements may necessitate the observance of particular
regulations.
If in doubt, ask your responsible safety officer or contact the REHM customer service
department. The special instructions listed in the supplier documentation for intended
use must be observed.
National regulations also apply, without restriction, to system operation.
Welding power sources may not be used to defrost pipes.
Intended use also includes compliance with the prescribed assembly, disassembly
and reassembly, commissioning, use, maintenance and disposal measures. Please
pay particular attention to the information in Section 2, Safety instructions and Section
13.5, Proper disposal.
The system may be operated only under the aforementioned conditions. Any other
use is considered unintended use. The operator bears the consequences of
unintended use.

Introduction
9
1.3 Symbols used
Enumerations preceded by a bullet point: General enumerations
Enumerations preceded by a square: Work or maintenance steps that must be
performed in
the order listed.
Section 2.2, Warning symbols on the system Cross reference: here to Section
2.2, Warning symbols on the system
Bold text is used for emphasis
Note!
... indicates practical tips and other particularly useful information.
The safety symbols used in this manual: Section 2.1
Typographic
distinctions
Safety
symbols

Safety information
10
2 Safety instructions
2.1 Warning symbols in these operating
instructions
This or a symbol that more accurately specifies the risk can be found in all of
the safety instructions given in these operating instructions where there is
danger to life and limb.
One of the signal words below (Danger!, Warning!, Caution!) is used to indicate
the severity of the risk:
Danger! …warning of immediate danger.
Death or serious injury may result if the warning is not heeded. The hazard
is illustrated with a pictogram in the margin.
Warning! ... of a potentially dangerous situation.
Death or serious injury may result if the warning is not heeded.
Caution! … warns of a potentially harmful situation.
Slight or minor injuries or property damage may result if the warning is not
heeded.
Important!
Notice of a potentially harmful situation. The product or an object in the
vicinity may be damaged if the warning is not heeded.
Materials that are hazardous to health and/or the environment.
Materials/operating materials that must be handled and/or disposed of in a
legally compliant manner.
2.2 Warning symbols on the system
Labelling of hazards and hazard sources on the system.
Danger!
Risk of electrical shock!
Non-observance mas result in death or injury.
Warnings and
symbols

Safety information
11
2.3 Notes and requirements
The system was developed and designed according to the generally accepted
rules of technology.
Nevertheless, residual dangers to operator life and limb or the risk of damage to
the system or other property may still arise during system use.
Safety equipment must never be dismantled or put out of operation, since doing
so will result in hazards, and the intended use of the system will no longer be
guaranteed. The dismantling of safety devices for equipping, repairing, and
maintenance is described in detail. The safety devices must be refitted immediately
on completion of such work.
When using external aids and agents (for example, solvents for cleaning) the user
of the system is responsible for ensuring the safety of the unit.
All safety instructions and warnings and the nameplate on/near the system must
be kept visible and legible.
Safety information serves to promote occupational health and safety and prevent
accidents. It must be adhered to.
In addition to the safety instructions listed in this section, the safety instructions
contained in the current text must also be observed.
Beside the advice given in these operating instructions, the general safety and
accident prevention regulations (in Germany, among others UVV BGV A3, TRBS
2131 and BGR 500 Section 2.26 (previously VGB 15): "Welding, cutting and allied
processes" and particularly the conditions for arc welding and cutting contained
therein or the corresponding national regulations) must be observed.
Also observe the safety information signs on the factory floor of the operator.
REHM welding machines are, except when REHM expressly states otherwise in
writing, for sale to commercial/industrial users only and are intended to be used by
commercial/industrial users only.
SYNERGIC.ARC welding systems are designed in accordance with EN 60974-1
Arc welding equipment - welding power sources for overvoltage category III and
pollution degree 3 and in accordance with EN 60974-10 Arc welding equipment -
electromagnetic compatibility (EMC) and may be used only on mains supply
systems which have a three-phase four-wire system with earthed neutral
conductor.
EMF measures:
Electromagnetic fields can be harmful to health in ways
that are as yet unknown:
- Effects on the health of those nearby, such as
those that need pacemakers or hearing aids
- Those who have pacemakers must consult their physician
spending time in areas near the device and the
welding process.
- Welding cables should be kept as far as possible from the welder’s head/trunk
- Do not carry welding cables or hose packs over your shoulder
or wrap them around your body.
Hazards of non-
compliance
Safet
y
information
Applications

Safety information
12
This Class A equipment is not intended for use in residential areas in whichpower
is supplied from a public low-voltage supply network. Such environments could
entail difficulties ensuring electromagnetic compatibilitybecause of interference
from wires and radiation. The welding equipment does not comply with IEC 61000-
3-12:2011. If the unit is to be connected to a public low-voltage supply network, it
is the responsibility of the welding equipment constructor or user, after consultation
with the supply network operator, to ensure that the installation can be connected.
SYNERGIC.ARC welding systems may be used only
as
intended
in an absolutely perfect condition

Safety information
13
WARNING
SYNERGIC.ARC welding systems have been subjected to a safety test and
acceptance. In the event of incorrect operation or misuse, there is a danger to
life and limb of the operator,
the machine and other material assets of the operator
the efficient work of the machine
All persons involved in the installation, commissioning, operation, maintenance
and repair of the machine must
be appropriately qualified
strictly observe these operating instructions.
Your safety is at stake!
SYNERGIC.ARC welding systems may be operated only by persons who are
trained and instructed in the use and maintenance of welding equipment. Only
qualified, assigned and trained personnel may work on and with the system.
The operator is responsible for third parties in the work area. The responsibility for
this machine must be precisely defined and adhered to. Unclear responsibilities
are a safety risk.
The operating company must
make the operating instructions accessible to the operator and
ensure that the operator has read and understood them.
Connect a lockable switch in front of the machine to prevent unauthorised
operation.
These operating instructions contain important information on how this unit can be
operated safely, properly and economically. A copy of the operating instructions
must be constantly at hand in a suitable place at the site of use of the system.
Before using the system be sure to read the information compiled in these
operating instructions. These include important instructions on use of the
equipment that enable the full technical advantages of the REHM equipment to be
exploited. See also the information on repair and maintenance, operating safety
and functional reliability.
These operating instructions are not a substitute for practical instruction by
REHM service personnel.
Documentation for any additional operation that may be present must also
be observed.
No mounting or incorporation of additional equipment or changes to the system
are permitted. Doing so will invalidate any warranty and liability claims.
Third-party intervention and disabling of operation of safety devices invalidates all
warranty claims.
High-power units can affect the mains voltage due to their high power
consumption. There may therefore be connection restrictions, requirements for
maximum permissible mains impedance, or requirements for minimum necessary
available power at the connection point to the general mains supply for certain unit
types (see technical data). If this is the case, the unit’s user – after consulting the
power supplier if necessary – must ensure that the unit may be connected.
Purpose of the
document
Changes to
the system
Requirements of
the mains supply
Qualification of the
operating
personnel
Dangerous nature
of this machine

Function description
14
3 Unit description
Figure 2: SYNERGIC.ARC 251, compact and gas-cooled
Front and rear view
(Figure does not illustrate standard equipment)
1
2
3
8
9
7
10
16
19
15

Function description
15
Figure 3: SYNERGIC.ARC 304 W, compact and water-cooled
View Front and rear view
(Figure does not illustrate standard equipment)
17
18
16
1
2
3 8
15
5 6
12
11
7
10
13
14
19

Function description
16
Figure 4: SYNERGIC.ARC 304 W, compact and water-cooled
Pole-reversible option (Figure does not illustrate standard
equipment)
3
10
6
12
5
7
4
9
11
8

Function description
17
Figure 5: SYNERGIC.ARC 404 WS with case and water cooling unit
Front view (Figure does not illustrate standard equipment)
6
1
2
3
7
5
22
10
9, 23
8
5
6
11
12
13
14

Function description
18
23
16
14
19
Figure 6: SYNERGIC.ARC 404 WS with case and water cooling unit
Rear view (Figure does not illustrate standard equipment)

Function description
19
Figure 7: SYNERGIC.ARC wire feed case
24
21

Function description
20
No. Symbol Function/description
1 Control panel – See "Description of controls"
2 Control panel push and rotary encoder
3 Welding torch connection (Euro connection)
4 Polarity selection plug for the torch connection (optional)
5 Connection coolant supply (Blue)
6 Connection coolant return (red)
7 Main switch for switching on/off the welding power source
8 Current socket "negative"
9 Current socket "positive"
10 Cooling air inlet
11 Inlet Filling Coolant Water cooling unit
12 Viewing window Stand Coolant Water cooling unit
13 Advanced trolley (option, non-standard)
14 Crane eyelets (optional)
15 Inert gas connection
16 Power cable
17 Welding power sources
18 Water cooling unit (Option)
19 Cooling air outlet
20 Coil mandrel
21 Wire feed unit
22 Intermediate hose set – control cable connection
23 Intermediate hose set – welding current cable
24 Coil mandrel
Table 1 Legend for functional elements on the front and back