Arc Machines 227 - Manual (Page 72)

MODEL 227
OPERATION MANUAL
Doc # 740063 Rev E
SECTION VII - CALIBRATION
7.2 CURRENT CALIBRATION
The M-227 contains components for measuring the actual amount of current. Normal
calibration is intended for adjusting the circuitry based on measuring these devices.
True verification of current output for Quality Control purposes must be done with an
External Calibration Shunt that is calibrated by an independent agency and controlled
by a QC or QA department. An external shunt adequate for this use is sold as a M-
227 option.
This procedure is written to include both calibration using internal devices for
measuring and for using the external shunt option provided by AMI.
A weld schedule is required for calibration. The first time calibration is done it will
have to be CREATED. Step 1 of the following schedule has a place for writing in the
Weld # when it is created. Six levels shall be programmed, odd numbered levels (1,
3, 5) shall be set to 100 amps and even number level (2, 4, 6) settings will be at 10
amps.
1. Select Weld Schedule Number ____ and verify that it is programmed as follows:
LVL
1-6 PULSE
OFF ROT
OFF PRI--RPM-BCK
0.00 0.00
LEVEL 1
LVL
1, 3, 5
TIME
20 PRI-AMP--BCK
100 0 PRI-PULSE-BCK
0.00 0.00
LVL
2, 4, 6
TIME
20 PRI-AMP--BCK
10 0 PRI-PULSE-BCK
0.00 0.00
PRE-PURGE-POST
10 10 UP-SLOPE-DOWN
1.0 1.0 ROT--DLY
CW 0.0
2. Set up a Weld Head rated for 100 amperes continuous duty and insert a tube or
pipe that can withstand 100 amperes of continuous current with no rotation. A
copper rod is good for this. If either one of these is not available use a Hand
Torch on a large plate with the torch fixed so it cannot change the gap during
calibration. It is also possible to purchase a Carbon Pile that will take the place of
a torch or weld head. In any case make sure that when an arc is struck nothing
will overheat or melt.
7.2