“phase” Phase angle between current and voltage signals is set up by the control
knob. Pressing the pushbutton below the display selects the range of
phase. When the indicator “L” light is on, the range is 0 to +90 and when
the indicator “C” light is on, the range is 0 to -90. In both case the value
and sign of phase are shown on display. Note that all ranges allow the
output to be set above the range full scale to allow overlap between
ranges.
“voltage” The amplitude of the voltage signal is set up by two control knobs (coarse
and fine). Pressing the pushbutton below the display selects the range of
voltage, 57V, 110V, 220V or 500V.
“current” The amplitude of the current signal is set up by two control knobs (coarse
and fine). Pressing the pushbutton below the display selects the range of
current, 1A, 5A, 20A or 100A. Switching on/off the 100A current range
operates a high current relay inside the calibrator. The operation of the
relay can be heard by the operator.
“distortion” The total harmonic distortion (thd) content of current and voltage signals
can be set up by means of pre-set trimmer control on the front panel.
Pressing the pushbutton selects thd on or off, and this is shown by an
indicator lamp. The output voltage and current signals can be distorted
from 1% to 15% with the third harmonic signals. The distortion spectrum
corresponds to a square wave at triple frequency. If a precise level of
distortion is required, a distortion analyzer should be connected to the
output while the trimmer is adjusted.
On the rear panel are:
Power supply socket 230V+/-10% at 50Hz/60Hz +/-5%. 110V +/-10% 60Hz, on order option.
Power supply fuse is slow blow rated at 1.6A/230V, or 3.15A/110V
Socket DB25 (used to three phase set)
Power supply voltage and frequency must be consistent with the details stated in
the specifications (Chapter 3). To avoid shock hazard or instrument damage, ensure that the
calibrator power ground is connected to earth ground on the correct pin. A factory-supplied,
three-conductor power cord, is supplied with the calibrator.
After switching on the power, for safety reasons, the calibrator’s output current and voltage
terminals are automatically switched to standby mode. The set value of current, voltage
frequency and phase are shown on the displays. Warming up of the calibrator should take no
longer than 30 minutes. After this time the calibrator is ready for use and performance will be to
specification.
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