iPAK2 User Guide
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14. Terminology
Term Description
Constant current Closed loop control of weld current resulting in the weld current being
regulated to a programmed value.
CT See Current transformer.
Current transformer A coil of wire wound on a circular core. This is used to measure the current in a
cable passing through the circular core. iPAK2 can use a CT to measure
primary current.
Cool time The time between weld pulses.
Downslope A linear decrease in current from the Main heat value to a final value.
Downslope time Time taken for the welding current to decrease from the Main heat value to a
final value. Expressed in mains cycles.
End of sequence An output that switches on as the electrodes open on completion of a weld.
The output indicates the end of the weld sequence.
EOS See End of sequence.
HAV Hi-lift Air Valve. See also Retract.
Heat A measure of power put into a phase angle controlled (non- constant current)
weld. The Heat relates directly to the firing angle on the mains voltage
waveform. Expressed as a percentage.
Hold The time between the last application of current and the electrodes opening.
This interval allows the molten material created by the weld process to solidify.
Hold time The time period following the last weld pulse prior to the electrodes opening.
This period allows the molten material to solidify. Expressed in mains cycles.
IP address Internet Protocol address. A unique address used by devices on an Ethernet
network.
Initiation signal The signal that starts the weld sequence. See also Start signal
kA Kilo amp (1000 amps).
kVA Unit of power (1000 volt amps).
mA Milliamp (1/1000 amp).
mV Millivolt (1/1000 volt).
Off time In a Repeated weld sequence this is the time between sequences. Expressed
in mains cycles.
PHA See Phase angle control.
Pulse width (PW)
control
Open loop control of weld current using Heat setting. The welding current is
not regulated and can be influenced by external parameters such as mains
voltage and cable lengths.
Post-heat The application of current to prevent the weld cooling too quickly.
Pre-heat The application of current prior to welding for the purpose of burning through
plating or surface contamination.
Presqueeze The time interval in a weld sequence for the electrodes to close onto the work
piece.
Presqueeze time The time allowed for the welding electrodes to close onto the components to
be welded. Expressed in mains cycles.
Primary current The current in the primary winding of the weld transformer which is the current
drawn from the mains whilst welding.
Program select A group of inputs representing the binary value of the weld program to be
used.
Proportional valve A device for regulating air-line pressure. Controlled by 0 to10 V dc signal.
Pulsations The number of times the Main heat interval is repeated during the sequence.
Successive applications of Main heat are separated by Cool2 time.
Retract The electrodes have two open positions: fully open to move the weld gun to
and from the work piece, and a working position for welding.
Retract air valve For use on a gun where the electrodes can be opened and closed in two
stages. This is an electrically operated valve for admitting air to the air cylinder
that controls the electrode movement.
2nd stage A signal required to allow the weld sequence to proceed.
Secondary current The current in the secondary winding of the weld transformer which is the weld
current.