Duty Cycle; Technical Data - ESAB LHJ 425 Manual De Instrucoes

2) DESCRIPTION
LHJ 425 is a welding rectifier for craftsmen or industry . It has good welding characteristics and a wide
current range, 55 - 425 A, which permits welding with a large number of different types of electrode including
basic, with diameters of 2.0 - 6.0 mm.
LHJ 425 is a fan cooled three phase rectifier connected to a power socket between three phases. The
welding current is continuously adjustable within the range 55 - 425 A by means of a hand crank at the front
plate. An scale on the front panel shows the set welding current.
The rectifier has a movable leakage core. By varying the magnetic field by means of this leakage core,
adjustment of welding current is stepless.
The rectifier case is made of galvanized enamelled sheet steel and is so designed that the rectifier can be
used outdoors irrespective of the weather whitout extra protection.
For mobility in the workshop the rectifier is delivery in two options: with two solid rubber wheels and handle
or with a truck with four wheels and brake. For transport with a crane or travers there are two generously
dimensioned lifting eyes on the top of the rectifier.
It has an outlet (220V-10A) at the front panel and maybe install a digital volt/amp meter optional.

3) DUTY CYCLE

Duty cycle is the ratio of the time that a welding machine can provide the maximum welding current (charge
time) to a reference time; in according to international standards, reference time is 10 minutes.
Example: The nominal duty cycle of 60% means that a machine can repeatedly provide its nominal welding
current during periods of 6 minutes (charge), followed by a 4 minute rest (the machine does not provide
welding current) (6+4= 10 min.). This process is repeatedly done so that the temperature of its internal
components does not exceed the limits stated in the project. The same goes for any value of duty cycle.
The duty cycle of 100% means that the machine can provide specified welding current non-stop, in other
words, with no need to rest.
In a welding machine, the allowed duty cycle increases up 100 % as the used welding current decreases;
inversely, the allowed duty cycle decreases as the welding current increases up to its maximum range.

4) TECHNICAL DATA

TABLE 4.1
EQUIPMENT
Welding current range
Open circuit voltage
Permitted load
at 100% duty cycle
at 60% duty cycle
at 30% duty cycle
Power Supply (V-Hz)
Rating for 60% duty cicle (KVA)
Thermal Class (°C)
Dimensions (w x d x h - mm ) with handle
Dimensions (w x dl x h - mm ) with trolley
Weight (kg)
LHJ 425
55 A/ 22 V 425 A / 33 V
76
230 A / 30 V
300 A / 32 V
425 A / 37 V
220/380/440 - 50/60
24.3
H (180 °C)
760 x 1130 x 720
780 x 950 x 870
185
15
LHJ 425