50, 1, 2, and 10-Turn Current Coil
Specifications
3
Specifications
Calculate Total Specification
The total specification of the effective current that the clamp meter measures is a function of
the clamp/coil interaction and of the current calibrator. To determine the total specification
use this formula:
Example:
A Fluke Calibration 5560A Calibrator supplies 13 A at 60 Hz to the 55XXA/COIL 50 generating
an effective current of 650 A (50 x 13 A), 60 Hz). The 1-year specification of the Calibrator at
13 A is ±(0.07 % + 8 mA), which is equivalent to 0.13 % of the 13 A calibrator output. The total
specification of the calibrator and the coil together as a percentage of the output:
Specification of calibrator current = ±0.13 %
Specification due to the Coil = 0.65 %
The RSS of these two specifications determines the total specification of the source/coil
combination:
For higher frequencies or higher current levels, the compliance voltage may exceed 1 V. If the
compliance voltage exceeds 1 V, then compliance adders must be added to the Calibrator
specification.
55XXA/COIL 50
55XXA/COIL 10
Number of turns
50
1, 2, or 10
Maximum Current
20 A rms, continuous
30.2 A rms, 5 minutes
30.2 A rms, continuous
Maximum Duty Cycle Derating
<20 A, continuous
>20 A, 50 % Duty Cycle
-
Maximum Voltage, All Inputs
30 V to Earth
Minimum Inner Diameter of Clamp Jaws
23 mm
1-Turn: 3 mm
2-Turn: 6 mm
10-Turn: 10 mm
Coil Ratio
±
0.65 %
[1]
,
DC
to 440 Hz.
[1] Includes coil/clamp interaction but does not include current source errors.
S
2
coil
+ U
2
source
S
total
=
0.112 + 0.562 + 0.66%
S
total
=
