section 6
6.4.4 procedure for verifying calibration of digital meters.
Voltmeter
1. Connect a digital meter known to be calibrated to the positive and negative output bus bars.
2. Compare the power source voltmeter reading to the calibrated meter reading. Readings should match within
±0.75%.
Ammeter
1. External to the power source, connect a precision shunt in series with the work lead(s). The best shunt is one with a
value of 100 micro-ohms (50mV / 500A or 100mV / 1000A) and a calibrated tolerance of 0.25%.
2. Use a calibrated 4 ½ digit meter to measure the output of the shunt. The amperage indicated with the external shunt
and meter should match power source ammeter to within 0.75%.
6.5 control circuit interface using J1 connector
Interface to the ESP-400C control circuitry is made with connector J1 on the front panel. J1 has 19 conductors.
J1-A and J1-B provide access to the galvanically isolated transistor output signal indicating an "Arc On" condition. See
Subsection 6.8, Arc Current Detector Circuits. J1-C and J1-D are the inputs for the remote Voltage Reference Signal that
commands the ESP-400C output current Subsection 6.9, Current Control Pot & Remote Vref. J1-F and J1-G supply 115V AC
for remote controls. See Subsection 6.6, Auxiliary Main Contactor (K3) & Solid State Contactor Circuits and Subsection 6.6,
Pilot Arc Hi/lo Circuit.
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