VPE-1911 Branch Current Monitor I/O Module

VPE-1911 Branch Current Monitor I/O Module

The VPE-1911 is a 42 point Current Transformer (CT) interface. Low voltage operation, circuit isolation and standard Modbus RTU RS485 interface makes this a versatile interface for any branch current monitoring application.

The VPE-1911 can be used with the VPE-2051 CT strip (max 21 CT’s per strip, 2 CT strips per interface) or with the VPE-2305 CT break out module with terminal blocks for split core CT’s.

Standard Features:

• Low Power (12 - 24 VDC), Nominal 24 VDC, Supplied via CAT5e Cable

• Up to 42 Current Transformers, 21 CT's Max per Ribbon Cable connection

• CT Load Resistor = 50 Ohms (100 Ohms on each Interface Channel, 100 Ohms on each channel on the VPE-2051 CT Strip and 100 Ohms on each channel on the VPE-2305 break out module)

• True RMS Current Measurement

• RS-485 Output, Half Duplex, Fault Tolerant Isolated Driver IC, 2 x RJ45 Jack (Power and Data)

• MODBUS RTU Protocol, ID Dipswitch Selectable, Baud Rate Jumper Selectable (9600 or 19.2K Baud)

• ICE FPGA as Main Processor

• High Precision 16 bit A/D Converter

• 1500 VAC Isolation Between Signal Conditioning and Communication Circuits

• DIN Rail Enclosure 4.375" DIN Length x 3.5" Wide x 1.375"High (Above DIN Rail)
  

• LED Indicators, Power (Blue), RS485 Tx(Red) and Rx (Green), Fault (Red), Heatbeat (Green)

Block Diagram:

Field Connections:

Using the VPE-1911 with Current Transformer Strips (CT Strips)

Most breaker panels are designs with 2 rows of breakers - the odd numbers are on the left and the even numbers are on the right. The VPE-2051 CT strips are available in different sizes (12m 15m 18 and 21 CT's per strip) to accommodate just about any breaker panel.

Using the VPE-1911 with Split Core Current Transformers

For current monitoring applications where the wiring is already installed, using split core transformers are ideal for measuring current loads. The VPE-2035 break out module is ideal for wiring in split cire current transformers into the VPE-1911 Branch Current Monitor I/O Module.

Using two break out modules, each VPE-1911 BCM Branch Current Monitor I/O Module can measure up to 42 current loads. The picture above shows 2 split core transformers (open) in circuits 1,2 and 3 and 3 split core transformers (closed) in circuits 22, 23 and 24.

Modbus Holding Registers

The VPE-1911 BCM I/O module is simple to use using the Modbus RTU RS485 protocol.

Using Funtion 3 (Read Holding Register):

HR 0 = CT 1 Value in Amps x 10

HR 1 = CT 2 Value in Amps x 10

HR 2 = CT 3 Value in Amps x 10

 "

 "

"

HR 40 = CT 41 Value in Amps x 10

HR 41 = CT 42 Value in Ampls x 10