CHAPTER 3: USING UB25 WELDING FUNCTIONS
UB25 LINEAR DC RESISTANCE WELDING CONTROL
3-10
990-665
The use of a current limit monitor for the first pulse enables the pulse to be terminated when a
predetermined amount of current flow is achieved. The rise of the current waveform is proof positive
that the oxide is breaking down and the parts are fitting up together, ready to weld. The first pulse,
therefore, should be programmed to be much longer than generally required. The power supply will
terminate the pulse based on the reading of current in the power supply’s monitor.
Instructions
Instructions for programming for Active Part Conditioning are listed in
Chapter 4, Operating
Instructions
.
Energy Limits
Applications
•
Part-to-part positioning problems
•
Electrode-to-part positioning problems
•
Parts with narrow weld window
Energy Limits
can be used in two different ways:
•
To detect work piece resistance changes that occur when parts are positioned incorrectly at the
weld head. In this case, the energy limits
will prevent blowouts, parts damage, and electrode
damage. Limits can be set to terminate the weld if this occurs.
•
To stop the weld when a sufficient
current
,
voltage
, or
power
level is reached. Using limits in
this way ensures a more consistent input of energy, which produces consistently good welds.
Description
This function terminates the weld energy during the welding process if pre-set weld
current
,
voltage
,
or
power
limits are exceeded. In addition to inhibiting the weld, the Power Supply has four
programmable relay outputs which can be used to trigger alarms to signal operators of weld faults, or
signal automation equipment to perform pre-programmed actions, such as stopping the production
line so the faulty weld piece can be removed.
The monitor measures the weld energy parameters during the weld period and compares the
measurements against the programmed limits. If any of the programmed limits are exceeded, the
energy limits monitor sets the Power Supply to a state selected from the
OUT OF LIMITS ACTION
menu. In addition, the Power Supplies relays can be programmed to trigger alarms, or trigger an
action in an automated welding system.
