Operating Instructions PA-xxP
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2.2
Introduction
Thank you for purchasing this MacGregor Arc welding power source.
This manual is designed to help the new user to understand and operate the equipment
quickly and safely. Please take a few moments to become familiar with the equipment
and this manual before attempting to use the equipment.
The following information covers the model you have purchased and others in the range
and should be kept for reference. This will also help you identify model specific features
mentioned in this manual.
All PA-xxP’s are comprised of a linear DC power unit controlled by a microprocessor and
colour touch screen interface.
It is the user's responsibility to ensure that their installation is safe both electrically
and mechanically.
The PAxxP allows you to program the delivery of electrical energy into a weld by allowing
adjustment of time and amplitude. Typically, energy into the weld is gradually ramped up,
held at a peak and then reduced. The amount of energy will depend on the length of
these times together with the value of the peak amplitude achieved. In some cases it is
beneficial to use 2 pulses in a weld, usually with the first pulse acting as a means of pre-
conditioning the parts.
A weld profile that is used to make a satisfactory weld can be saved as a PROFILE in the
units memory.
The starting system of the PAxxP range has been optimised for low current use. The arc
is stuck by a 12KV impulse, which starts current flowing in the 5A unregulated supply
(rated at 200Vdc). Once the auxiliary current is detected, the main controlled current is
turned on. This lower voltage and higher current (up to 60Amps at 80V DC depending on
model), then controls the weld and the auxiliary system is switched off.
Unlike conventional arc welders, where this can take several milliseconds, the PAxxP
achieves this in under 700uS, giving more precise low current/power control.
8Amps
PAxxP Output
5Amps
Reduced uncontrolled
Energy in auxiliary.
700uS
10Amps
Conventional Welder
2 mS
PLEASE NOTE :- DUE TO THE REDUCED UNCONTROLLED AUXILIARY ENERGY,
IT MAY BE NECESSARY TO ADJUST YOUR SETTINGS IF REPLACING A
CONVENTIONAL WELDER.