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CALIBRATION PROCEDURES
TIPS FOR CALIBRATION
TIPS FOR USING A LOAD BANK
• Set the load bank for 100A over the maximum
output of the machine under test.
• Set the machine under test to its 100% IEC rated
current.
• Apply load.
• At rated current, the voltage should be
Voltage=Current*.04+20
• If needed remove load and adjust load bank to
get the desired load. (Current and Voltage)
TIPS FOR CURRENT CALIBRATION VERIFICATION
• Select the proper equipment. Current should be
measured using a certified, calibrated shunt and
millivolt meter.
• Locate the meter a minimum of 5ft (1.5m) from
the power source. Theoretically, the current flow
is the same anywhere in a closed loop path, but it
is good practice keep the meter away from the
power source to reduce the likelihood of electrical
interference.
TIPS FOR VOLTAGE CALIBRATION VERIFICATION
• Calibrate at the output studs whenever possible.
• Special filtering may be required for accurate
measurement of the stud voltage. The output
voltage waveform at the studs can be vastly
different than the voltage waveform at the load.
This is primarily due to the inductive reactance of
the weld cables.
o M25303-1 Filter kit is available to bypass
inverter noise.
• Never place the meter on or near the power
source or weld cables. Any reasonable
separation distance will reduce the likelihood of
electrical interference.
INVERTEC V276 CALIBRATION
PROCEDURE
LOAD BANK INSTRUCTIONS
1. Connect machine output studs to load bank and
testing equipment (see TIPS FOR CALIBRATION
section for proper testing equipment)
2. Set load bank to 375A
3. Turn on Invertec V276
4. Place mode toggle switch into SMAW mode
5. Turn output knob until current meter reads 200
6. Turn on load bank.
7. Apply load
8. Adjust output knob until calibrated shunt reads a
millivolt signal equal to 200A
9. Check output voltage AT THE STUDS with a
calibrated volt meter
10.
Check against meters on the V276
11.
Record readings and differences.
MAINTENANCE
DETERMINING CURRENT AND VOLTAGE
OFFSETS
• For the current offset take the reading from the
calibrated shunt and subtract the reading from the
V276's meter.
• For the voltage offset take the reading from the
calibrated meter and subtract the reading from
the V276's meter.
• Record these numbers. These values (-10 to 10
for current; -3 to 3 for voltage) are what you will
enter into the machine to adjust calibration
HOW TO ENTER CALIBRATION MODE
1. Power machine on.
2. Put in GTAW Mode, ARC FORCE to 0, and HOT
START off.
3. Turn output control knob all the way counter-
clockwise.
4. Turn output control knob all the way clockwise.
5. Turn output control knob all the way counter-
clockwise.
6.
Steps 3-5 describe 1 knob turn cycle, repeat 3-5
an additional 4 times for a total of 5 cycles. 5
cycles must be completed within 20 seconds to
enter calibration mode.
7.
Calibration mode has been entered. The display
will show old in addition to a number on the other
display.
8. Toggle the local/remote switch to change
between viewing previously set A and V offsets.
(machine's factory default is 0A and 0.0V offsets).
9. Move the SMAW/GTAW switch to SMAW to
change the A and V calibration offsets.
10.
While SMAW and REMOTE are selected, use
the output control knob to change the voltage
offset (-3.0 to 3.0V).
11.
While SMAW and LOCAL are selected, use
the output control knob to change the current
offset (-10A to 10A).
NOTE: Both Current and voltage must be
calibrated at the same time. If the offset on one is
zero, be sure to set the offset to zero.
12.
To save your selections put the switch in
GTAW, the previously selected values are now
present (marked old on display) and viewable for
A and V using the LOCAL/REMOTE Switch.
13.
When finished making adjustments, cycle
power to the machine. Please allow 5 seconds
with the switch in the OFF position before turning
back ON.
14.
The changes are now saved and will remain
saved until overwritten by entering calibration
mode again.
ES 276i
D-4
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