Arc Shutdown Time; Arc Recovery Test; Arc Recovery Time - Advanced Energy Pinnacle 20 kW Manual

Arc Shutdown Time

Arc shutdown time is the length of time that the Pinnacle supply interrupts power flow in
response to an arc. Selecting a target type of "metal" or "non-metal" will pre-select arc
shutdown times for you. However, if you want a custom arc shutdown time, select one based
on system conditions. To extinguish an arc properly, the power supply must interrupt power
until the output (arc) current decays to a value near 0. The decay of output current largely
depends on system cable inductance and the impedance of the arc. If you select an arc
shutdown time that is shorter than the actual decay time of the arc current, then the Pinnacle
automatically extends its arc control circuitry. You can set a custom arc shutdown time
through the ARC menu on the Pinnacle Active Remote Panel or through AE Bus/Profibus
Command 8 (see Chapter 4).
Note: 10 kW and 20 kW Pinnacle units with a 208 V input configuration have a minimum arc
shutdown time of 50 μsec.

Arc Recovery Test

After the arc shutdown time has expired, the Pinnacle supply reapplies output power to the
load and examines the output voltage level. The output voltage must rise above your selected
V-arc trip level within an internally fixed time of 20 μs. If the output voltage rises above the V-
arc trip level before the 20 μs period has ended, the Pinnacle power supply will resume normal
output. If the output voltage does not rise above the V-arc trip level by the end of the 20 μs
time limit, then the Pinnacle unit initiates another arc shutdown. Metal flakes and unusually
dirty target conditions may be responsible for multiple arc shutdowns. Connecting large
capacitors (>.047uF) on the Pinnacle output can hinder the Pinnacle from achieving proper
output voltage within 20 μs.

Arc Recovery Time

Recovery to the pre-arc output level usually occurs in less than 25 μs from the end of your
selected arc shutdown time. This recovery time is typical when you have selected a metal
target or an arc shutdown time between 10 μs and 2500 μs. However, it may be too rapid for
some processes. Some target materials respond better to a slow (or "soft") recovery period. A
"soft" recovery allows for greater plasma stability at the time of recovery or prevents any
possibility of overshooting the operating point. If you select an arc shutdown time of 500 μs or
greater, the unit automatically selects a 1 ms "soft" recovery time period.
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Operation
Pinnacle™ 20 kW
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