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MAINTENANCE
6. Calibration
6.1
Closed-box Calibration
The 7500 features closed-box calibration. The advantage of closed-box calibration is that the user
does not have to disassemble the case or make mechanical adjustments.
6.2
Calibration sChedule
Calibrate the 7500:
• After any repairs are performed.
• At least once a year; more frequently to ensure required accuracy.
6.3
Calibration Commands
Command Code
function
explanation
CAm1,m2<terminator> Calibrates amps measurement
value of present input range.
“m1” indicates the input phase.
Values for
m1
are:
0 = all phases
1 = phase 1
2 = phase 2
3 = phase 3
“m2” indicates the calibrated input
value applied to the input.
When m2 is equal to 0, the unit
assumes zero calibration is requested
and zero amps are on input.
When m2 is greater than 0, the unit
assumes gain calibration is requested
and m2 amps are on input.
CVm1,m2<terminator> Calibrates volts measurement
value of present input range.
“m1” indicates the input phase.
Values for
m1
are:
0 = all phases
1 = phase 1
2 = phase 2
3 = phase 3
“m2” indicates the calibrated input
value applied to the input.
When m2 is equal to 0, the unit
assumes zero calibration is requested
and zero volts are on input.
When m2 is greater than 0, the unit
assumes gain calibration is requested
and m2 volts are on input.
CS<terminator>
Saves calibration values to
EEPROM.
---
CR<terminator>
Restores all calibration values
from EEPROM (used for
testing only).
---
BCALm1<terminator> Set the device to calibration
mode
Value for m1 are:
0 = Disable Calibration Mode
1 = Enable Calibration Mode
