Novatech Bitronics M87X Series, Manual

Page: 102 / 184

ML0021 August 15, 2018
86
Copyright 2018 Bitronics, LLC
7.0 SIGNAL INPUT MODULE S10 - S12, S1C (M871), S13 - S17, S2C (M872)
7.1 Introduction
The Signal Input Module provides the terminal blocks, current transformers, and voltage
input dividers for the signals to be measured. Compensation for normal variations in input
circuits is achieved by storing calibration constants in non-volatile memory (EEPROM),
which resides on the Signal Input Board. These constants are factory-programmed to
provide identical signal gain (attenuation) in each of the 14 signal input paths. Checksums
are incorporated into the EEPROM, which are read periodically by the microcontroller to
check the integrity of the calibration constants.
7.2 Features

Utility-grade current input terminal block with 10-32 studs (M871) or 8-32 screws
(M872)

Current shunts are #12 AWG SIS, 600V wire, crimped ring-lugs with brazed seams

Options for split-core CTs (external)

Voltage measurements to 424V rms line-to-neutral (730V rms line-to-line)

7kV, 7.5M Ω input resistors on voltage inputs.

Removable voltage input terminal block accepts bare wire or terminal lugs.

Non-volatile memory backup of CT/VT calibration data