CHAPTER 1: DESCRIPTION
UB25 LINEAR DC RESISTANCE WELDING CONTROL
1-6
990-665
UB25 Operational States
STATE
DESCRIPTION
RUN
This state indicates the Power Supply is ready to weld and waiting for a start signal. Press the
RUN
key on the front of the Power Supply to put the Power Supply in this state.
NO WELD
In this state, the Power Supply does
not
deliver weld energy to the weld head heads in order to
prevent electrical shock. This state is used for cleaning electrodes or adjusting the air regulators on
air actuated weld. If a start signal is received, the Power Supply will execute its programmed weld
schedule(s) -- but
no
energy will go to the weld head, and the LCD will display a
WELD SWITCH
IN NO WELD POSITION
alarm. The
WELD/NO WELD
switch toggles the Power Supply
between the
WELD
and
NO WELD
states.
PROGRAM
In this state, the weld time and energy values can be modified and new schedules can be selected.
From the
RUN
state, press any one of the
WELD SELECTOR KEYS
to put the Power Supply in
the
PROGRAM
state.
TEST
When a weld schedule is changed, the Power Supply has the capability of performing a
TEST
weld
in order to optimize the feedback control loop and produce the fastest rise-time, minimum-overshoot
weld pulse. The Power Supply can be programmed to
ALWAYS
do a test weld after a schedule is
changed,
ASK
to do a test weld after a schedule is changed, or only
IF REQUIRED,
do a test weld
after a schedule is changed.
STANDBY
When an air actuated weld head is being used, the Power Supply will go to the
STANDBY
state
when the footswitch is pressed.
SQUEEZE
When a start signal has been received, the Power Supply enters the
SQUEEZE
state for the duration
programmed in the schedule. An adequate amount of squeeze time should be programmed to allow
the weld head to settle before the
WELD
period begins. The default
SQUEEZE
time is 150
milliseconds.
NOTE:
In addition to the debounce time, there is a delay of no greater than 2.5ms
before the start signal is recognized by the Power Supply.
WELD
The
WELD
period begins after
SQUEEZE
time has ended and includes both weld pulses as well as
the Cool time between Pulse 1 and Pulse 2.
HOLD
The
HOLD
period begins after the
WELD
period ends and lasts for the duration programmed in the
schedule. An adequate amount of hold time should be programmed to allow the electrodes to sink
the heat away from the welded parts. The default
HOLD
time is 50 milliseconds. It is during the
HOLD
time that the weld strength is formed.
END
The Power Supply will enter the
END
state after the
HOLD
period if the firing switch or footswitch
has not yet been released.
MONITOR
This state allows you to view waveforms of weld
voltage
,
current
,
power
, and
resistance
. Press
the
ENERGY
key to go to the
MONITOR
state. The LCD will show the actual trace of energy of
the last weld performed. You can also view the peak or average energy value for each weld pulse as
selected by pressing the
PEAK/AVERAGE
key. If a start signal is received while in the
MONITOR
state, the Power Supply will execute the programmed weld schedule and the waveform trace will
update with the new weld data. The operational state will then read
RUN
, and the LCD screen will
show the monitored data.
ALARM
The Power Supply automatically goes into an alarm state when it recognizes any alarm condition
(these are described in detail in
Appendix E
,
LCD Display Messages
).
MENU
Pressing the
MENU
key puts the Power Supply in the
MENU
state, which displays the
MAIN MENU
on the LCD. A series of menu and sub-menu screens enable you to change the Power Supplies
operating parameters (see
Chapter 4, Operating Instructions
).
