7
Operating Manual
Description
POWERmax
2
is a powerful, primary-switched welding
rectifier with a drooping characteristic and very low
upper rippling of the welding current to manual metal
arc (MMA) and TIG welding on direct current.
The electronic structure of the product facilitates spat-
ter-free MMA welding with a high degree of arc stability
even with basic and high-alloy electrodes. The built-in
hot start device provides problem-free ignition of all
electrodes.
The welding rectifier POWERmax
2
has been designed
in compliance with the guidelines of Euro-standard EN
60974-1 and carries the CE conformity symbol.
Use of the product is permissible for welding work pla-
ces with increased electrical hazard and as such is la-
belled with the symbol .
In the event of a short-circuit at the output, an integra-
ted safety switch cuts off the power within approxi-
mately 1 second.
Safety Precautions
o
Before opening up any machine, always pull out
the mains plug first, or otherwise ensure that the
machine is "dead".
o
Components, assemblies or other units may
only be started up once they have been installed
inside a shockproof housing. They must be
"dead"
(i. e. without current) while being in-
stalled.
o
Tools may only be used on units, components or
assemblies once it has been ensured that the
units are disconnected from the voltage supply
and that any electrical charges stored in compo-
nents inside the machine have been dis-
charged.
o
Live cables or leads connected to units, compo-
nents or assemblies must be checked regularly
for signs of insulation faults or breaks.
If any defect is found in the power supply lead,
the unit must be withdrawn from service imme-
diately, until the defective power lead has been
replaced.
o
Where new components and assemblies are fit-
ted, attention must constantly be drawn to the
importance of adhering strictly to the charac-
teristic data for electrical quantities given in the
accompanying descriptions.
If the descriptions provided for the non-indus-
trial final user do not make clear what electrical
characteristic values apply to a component, ad-
vice must be sought from a qualified expert.
Electrical Safety Measures when Arc-welding
Hazards from electric current
Both mains and welding current can be hazardous. It is
forbidden by law for anyone but a qualified electrician to
do anything with any parts which are in contact with
mains voltage. The only exception to this applies, of
course, to the power plug and the mains switch. When
repair or maintenance work is being carried out on the
power source, the machine must first be completely
disconnected from the mains. For all but the most minor
jobs on the machine in the course of which the operator
may have to leave the room, even if only briefly, the plug
socket(s) should be clearly blocked.
Protective earth conductor
Every 3-phase power supply system will have a PE
conductor. This is a non-live, earthed conductor and
connected with the housing of the machine. If an earth
fault occurs on the machine there is an immediate short
circuit between the PE conductor and phase, causing
the fuse on the corresponding phase conductor to blow,
and/or tripping the fault-current breaker
(FI).
Both the mains and the machine supply leads should be
regularly checked by a qualified electrician to ensure that
the PE conductor is functioning correctly.
Open-circuit voltage
The highest - and thus the most dangerous - voltage in
the welding current circuit is the open-circuit voltage.
The maximum permissible open-circuit voltages are
stipulated in national and international regulations ac-
cording to the type of welding current, the design of the
current source and the extent of the specifically electrical
danger posed to the workplace.
Rectifier power sources
A DC welding power source should be constructed in
such a way that if there is a fault in a rectifier
(e.g. open-
circuit, short-circuit or phase fault), the permissible AC-
values cannot be exceeded. Below, the open-circuit
voltage ratings to IEC 974
(1.1.90) for working under
normal conditions and for working under conditions of
increased electrical danger.
Working under normal conditions
For welding jobs done under normal conditions and
using simple equipment, the following open-circuit volt-
age ratings apply:
o
for DC - peak value 113 V
o
for AC - peak value 113 V, effective value 80 V
These max. voltages may be exceeded on appliances
equipped with an RC circuit, so long as - with the arc unlit
- the higher voltage does not occur for longer than 0.2
seconds.
Exceptions may apply in the case of fully mechanised,
automatic or other special procedures. For welding
current sources capable of delivering either DC or AC,
the respective regulations apply to whichever opera-
tional mode the machine is switched to.
Working under conditions of increased electrical
danger
Welding work in confined spaces, in cramped surroun-
dings, on or between electrically conductive parts, in
damp or hot spaces.
