SCMHVAS: High Voltage Attenuator System

Benefits

• Safe Attenuation of High-Voltage Signals
• Protects User Equipment from Lightning and Heavy Equipment
• Power-line Voltage
• Reduces EMC Concerns and Electrical Noise in Measured Signals
• Convenient System Expansion and Repair
• Signal Filtering in Noisy Environments
• Simplifies Sensor Interface and Signal Conditioning Design
• Provides Isolation of External Sensors
•  Breaks Ground Loops

Applications

• Analog Signal Conditioning
• Analog Signal Isolation
• Analog Signal Filtering
• High-voltage AC/DC Measurement
• Industrial Process Control
• Test and Measurement

Description

The SCMHVAS (Signal Conditioning Modular High Voltage Attenuator System) is an analog signal conditioning system designed to safely monitor and accurately measure voltage potentials up to 1414VAC (4000V peak-to-peak). These high potential voltages are typically found in industrial applications such as induction heaters, electric-motor drive controllers, and measurement of battery stacks. The system reduces the input signal to a level suitable for interface to data acquisition systems, while at the same time providing filtering characteristics and 1500Vrms isolation.

For each channel of analog input, an attenuator module, SCMHVASMxxxx, 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. 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 SCMHVAS-Mxxxx attenuator module are made using integrated terminal blocks for robust system assembly. For safety purposes, the terminal blocks are inside the shell and can only be accessed from the top. There are no exposed high-voltage points on the SCMHVAS-Mxxxx series modules, SCM5B30-07 or SCM5B40-07 module, or the mounting backpanel.

The SCMHVAS 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 SCMVASPB16 (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 for recommended ground connections and host system interfaces. Both the SCMVAS-PB8 and SCMVAS-PB16 backpanels can be mounted on the SCMXRK-002 19-inch metal rack. The SCMVAS-PB8 and SCMVAS-PB16 backpanels are forward compatible and can accommodate both, the original SCMVAS-Mxxx modules and the SCMHVAS-Mxxxx modules.