SAGEON PSMC I PRODUCT MANUAL
PM990-2999-00, Rev 5
3-14
When all the analog channels have been calibrated press “
Escape
” to return to the initial
“
Calibrate Gain
” menu. Use “
next
” or “
Previous
” to reach other Configure sub-menus, or
“
Escape
” again to return to the top Configure menu.
3.6.3 Shunt Calibration Calculations
In order to calibrate shunts, a suitable load current must be passing through it to use it for
calibration. The load current should be at least 70% or 80% of the full scale rating to get an
accurate calibration. A load box connected to the shunts output may be required to generate
the required current levels during calibration. Shunts are displayed in millivolts (mV) so they
can be compared to the DVM readings connected to the inputs.
Note:
The SAGEON PSMC I is hardware limited to reading only 50mv full-scale rated
shunts. In addition, only load currents from the main plant voltage can be monitored.
Battery discharge current and/or opposite polarity DC/DC converter output currents
can not
be monitored with the SAGEON PSMC I. For additional shunt monitoring
capability, including 100mV shunts, see the PSMC I Analog Expansion unit (PN 103-
3000-XX).
The resulting displayed calibrated current reading can be verified against the actual shunt
input performing the following calculation. Measure the actual milli-Volt input on at the
screw terminal inputs on the back of the SAGEON PSMC I for the particular shunt being
calibrated. Determine the shunts full scale rating; such as, 600A @ 50mV full-scale. Then
multiply the measured value by the full scale rating and divide the result by 50 to get the
actual current value. This calculated value should agree with the number of amps passing
through the load; within 2% of the shunts full scale rating.
Measured value = 30 mV,
Amps
mV
Amps
mV
Amps
Actual
360
50
)
600
(
30
_
=
=
3.6.4 Temperature Calibration Calculations
The SAGEON PSMC I utilizes UNIPOWER, LLC’ standard temperature sensor assemblies
that provide a calibrated output of 10 mV per degree Fahrenheit. For SAGEON PSMC I
Calibration the easiest method is to measure the sensor output on the temperature inputs at the
rear of the SAGEON PSMC I. Reading between the
SIG
and
RTN
with a DVM on the milli-
volt range provides a voltage that can be read directly as Degrees Fahrenheit. For example, a
reading of 782 mV can be read as 78.2°F for entry as the calibration value.
F
F
mV
mV
o
o
2
.
78
10
782
=
This value may also be read on the tip jacks located on the front panel, while the unit is set to
calibration or test mode and the corresponding sensor channel is selected. The PSMC
measures temperatures from 0°F to 200°F, i.e. voltage ranges from 0 to 2.00 Volts.
3.7 SET SHUNT SCALES
The PSMC can monitor plant current and nine “feeder” shunts. The calibrate zero and gain menus set-up
the hardware analog input channels to accurately read a 50mv shunt. In order to display the correct
ampere reading for each particular shunt the full-scale rating must be entered. The factory default setting
is 2500A for the PLANT SHUNT and 600A for all FEEDER SHUNTS, with a possible range of 5 to
10,000 Amps.
