Impulse SCMVAS-PB8 - Manual

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Isolated Analog Signal Conditioning Products SCM5B
SCM5B
SCMVAS
Voltage Attenuator System
Features
• Accepts High Voltage Signals up to 460VAC
(1300V Peak-to-Peak)
• 5 or 10 Volt Output for A/D Systems
• 1500Vrms Transformer Isolation
• True 3-Way Isolation
• Up to 160dB CMR
• ±0.06% Accuracy
• Panel or DIN Rail Mounting Options
• Approvals Pending
Description
The SCMVAS (Signal Conditioning Modular Voltage Attenuator System) is an
analog signal conditioning system designed to safely monitor and accurately
measure voltage potentials up to 460VAC (1300V peak-to-peak). These high-
level voltages are typically found in industrial applications such as induction
heaters or electric-motor drive controllers. The system reduces the input signal
to a level suitable for interface to data acquisition systems, while at the same
time providing various filter characteristics and 1500Vrms isolation (Figure 1).
For each channel of analog input, an attenuator module, SCMVAS-Mnnn,
pre-conditions the signal which is then filtered, isolated, and converted to a
high-level voltage output using an SCM5B30-07 or SCM5B40-07 module. The
SCM5B40-07 module with a 10kHz bandwidth is recommended for common 50/
60Hz signals low in harmonics where the user is interested in measuring only
AC voltage. The SCM5B30-07 module is used for low frequency AC signals
below 4Hz. For signals comprised of harmonics or noncoherent content, the
SCM5B33 True RMS Input module is recommended. Use of this module
provides a DC output that is directly related to input signal power, or the RMS
(Root Mean Square) value, allowing true RMS representation of input signals
ranging from pulses to complex nonperiodic waveforms. The attenuator and
signal conditioning modules have excellent stability over time and do not require
recalibration. Overall system accuracy is ±0.06%.
Input signal connections to the SCMVAS-Mnnn attenuator module are made
using a pluggable terminal block for ease of system assembly and reconfiguration.
For safety purposes, the terminal block has a cover over the screws and there
are no other exposed high-voltage points on the SCMVAS-Mnnn series mod-
ules, SCM5B30-07 or SCM5B40-07 module, or the mounting backpanel.
The SCMVAS system has two specially designed backpanels for mounting the
attenuator and signal conditioning modules. The SCMVAS-PB8 high density, 8-
channel backpanel (Figures 2, 3) can be panel mounted or DIN rail mounted and
provides the conditioned output signal on screw terminal blocks. Jumpers are
provided on each channel to optionally connect or isolate each module’s I/O
Common from other channel’s I/O Common and/or Power Common. The
SCMVAS-PB16 (Figures 4, 5) has 16 channels of analog I/O simultaneously
available to high-speed data acquisition (ADC) boards through a 26-conductor
ribbon cable. Refer to the SCMPB01 Data Sheet and Application Note AN502
in this catalog for recommended ground connections and host system inter-
faces. Both the SCMVAS-PB8 and SCMVAS-PB16 backpanels can be mounted
on the SCMXRK-002 19-inch metal rack.
Figure 1: SCMVAS Schematic