Obvius A90DC-12, A90DC-10 Installation And Operation Manual

A90DC-12 – DC Current Monitor

Obvius, LLC

Installation and Operation Manual

Model A90DC-12, A90DC-10

Date: Sep 4, 2013

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Copyright Information

Copyright © 2007 - 2013 by Obvius

Obvius, AcquiSuite and ModHopper are trademarks of Obvius Holdings LLC

Other brand and product names are trademarks or registered trademarks of their respective holders.

U.S. Government Restricted Rights: Use, duplication or disclosure by the Government is subject to restrictions set fourth in subparagraph (a) through
(d) of the Commercial Computer Restricted Rights clause at FAR 52.227-19 when applicable, or subparagraph (c) (1) (ii) of the Rights in Technical Data
and Computer Software clause at DFARS 252.227-7013, and in similar clauses in the NASA FAR Supplement.

Limited Warranty

OBVIUS IS PROVIDING THIS WARRANTY IN LIEU OF ALL OTHER EXPRESS OR IMPLIED WARRANTIES, INCLUDING ANY WARRANTY
OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. THIS WARRANTY IS BUYER'S EXCLUSIVE REMEDY FOR ALL
CLAIMS AGAINST OBVIUS. OBVIUS SHALL NOT BE LIABLE FOR ANY CONSEQUENTIAL OR INCIDENTAL DAMAGES. OBVIUS'S TOTAL
LIABILITY FOR ALL CLAIMS SHALL BE LIMITED TO THE PRICE PAID FOR ITS PRODUCT.

Obvius promises buyer that any standard product manufactured by Obvius shall be free from all material defects in design, material, or manufacturing for
a period of 2 years from the manufacture date; provided, however, that the warranty shall not extend to ordinary wear and tear or to normally replaceable
components (e.g., batteries). During the warranty period, Obvius may repair or replace (in its sole discretion) any product suffering from a warranty defect
and returned freight prepaid by buyer, with no charge to buyer for any warranty repair or replacement. The warranty shall remain in full force and effect
for such 2 year period, provided that the product: (1) was installed, operated, and maintained properly; (2) has not been abused or misused; (3) has not
been repaired, altered, or modified outside of Obvius's authorized facilities; (4) has not been sold subject to other warranty terms specified at the time of
sale; and (5) is still owned by the original purchaser. This warranty provides specific legal rights that may be varied by state law. Obvius's products are not
designed for life or safety applications.

Product Application Limitation

Obvius strongly believes in continuous improvement, therefore we must reserve the right to change specifications and product offerings without notice.
Where possible, we will substitute products with equivalent functionality when necessary.

DANGER

Hazard of Electric Shock, Explosion or Arc Flash

● Follow safe electrical work practices. See NFPA 70E in the USA, or applicable local codes.

● This equipment must only be installed and serviced by qualified electrical personnel.

● Read, understand and follow the instructions before installing this product.

● Turn off all power supplying equipment before working on or inside the equipment. Use properly rated voltage sensing device to

confirm power is off. DO NOT DEPEND ON THIS PRODUCT FOR VOLTAGE INDICATION

● Only install this product on insulated conductors.

Failure to follow these instructions will result in death or serious injury.

NOTICE

● This product is not intended for life safety applications.

● Do not install this product in hazardous or classified locations.

● The installer is responsible for conformance to all applicable codes.

● Mount this product inside a suitable fire and electrical enclosure.

FCC Part 15 Information

Note: This equipment has been tested by the manufacturer and found to comply with the limits of a class A digital device, pursuant to part
15 of the FCC rules. These limits are designed to provide reasonable protection against interference when the equipment is operated in a
commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in
accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a
residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense.
Modifications of this product without the express authorization of Obvius nullify this statement.

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Table of Contents

Markings and Symbols:...............................................................................................................................................................3

Overview......................................................................................................................................................................................4

Applications.................................................................................................................................................................................4

Installation Checklist...................................................................................................................................................................4

Hardware Overview.....................................................................................................................................................................5

A90DC-12, A90DC-10 Series Features and Specifications...................................................................................................5

Power and Communication Connections...............................................................................................................................6

Hardware Installation.............................................................................................................................................................6

Temperature...........................................................................................................................................................................8

Monitoring usage:........................................................................................................................................................................9

AcquiSuite Advanced Configuration Options................................................................................................................10

Modbus Features........................................................................................................................................................................11

Supported Modbus Functions..............................................................................................................................................11

Modbus Register List...........................................................................................................................................................11

Register formatting.........................................................................................................................................................14

Alarm configuration.......................................................................................................................................................14

Mechanical Drawings................................................................................................................................................................15

A90DC-12 Firmware Update.....................................................................................................................................................16

Markings and Symbols:

WARNING: A potential risk exists if the operating instructions are not followed

General Warning Symbol: This symbol indicates the need to consult the operating instructions provided with the
product.

This symbol indicates the presence of electric shock hazards.

This symbol indicates: Do not apply to or remove from hazardous live conductors.

Direct Current symbol.

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Overview

The A90DC-12 DC Series current monitor system is designed to allow measurement and alarming of DC current
applications including solar pv arrays, battery monitoring and DC power supplies for telecom switch gear.

The A90DC-12 uses 12 non-contact DC Hall Effect sensors to measure DC current on each of the 12 channels. DC current
can be measured in both directions, showing positive and negative numbers in the resulting measurement values. Data
values are made available via RS485 serial using the standard Modbus RTU protocol.

In addition to reporting the current values of each channel, the A90DC-12 also provides alarm functions to monitor
imbalances between channels. This feature is instrumental in detecting failed equipment in applications such as Solar PV
arrays.

Applications

The A90DC-12 Series DC Current Monitor has several applications. These include:

● DC Load Monitoring.

● Solar PV Power Generation

● Battery Charge and Discharge monitoring.

Installation Checklist

An A90DC-12 system installation has the following components:

Required hardware

● A90DC-12 Series DC current monitor (required)

● 24VDC power supply

● Data connection to a Modbus master device such as an AcquiSuite, ModHopper, PLC or computer software such as

the Obvius Config Console.

● Enclosure for the A90DC-12 DC to satisfy UL safety requirements.

● Shielded twisted pair wire for communications.

Note: If using the Obvius Config Console software, an RS232/DB9 or RS485 serial cable will be required to attach the
A90DC-12 to the computer.

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Hardware Overview

A90DC-12, A90DC-10 Series Features and Specifications

Processor Arm7 embedded CPU
LED Alive (green), RS485 TX, RX (yellow)
Protocol Modbus RTU
Addressing Modbus address may be set from 1 to 247 via Modbus register.
Power Supply Power input : 9-30vdc at 1.25W. (power supply not included)

140mA typical at 9vdc, 55mA typical at 24vdc. (excluding the 4-20mA sensor input channel)
Note: 24vdc required for use of the 4-20mA analog input port. When fully loaded, the maximum
current should not exceed 250mA.
Transient overvoltage rating 1500V

Current Inputs

Accuracy: +/- 5% of full scale (+/- 0.75A) at 25ºc
Analog input1: 4-20mA analog input:
Measurements DC current per channel, instantaneous and average

Alarming Low alarm may set as a percent of DC average of other channels.

Communications1RS-485 (+,-, S), 9600 baud, N, 8, 1, two wire. Supports up to 32 external devices (expandable)
Isolation The RS485 terminals electrically isolated to 1500V from the remainder of the A90DC-12 board.
Environmental

Safety UL61010 Recognized

EMC FCC CFR 47 Part 15, Class A
Size 12.85” x 2.5” x 1.75” (326mm x 64mm x 45mm)
Mass 0.83 lbs (0.375 kg)

2

12 DC Hall Effect Sensors, non-contact.
Maximum range +15Amps to -15Amps DC
The product is intended to measure insulated and uninsulated conductors and to be installed inside a
Listed electrical and fire enclosure.

0.49 inch by 0.35 inch opening for load wire.

Total DC current (sum of 12 channels), instantaneous and average
Average DC current (of 12 channels), instantaneous and average

Alarms may be disabled below a minimum average current level.
Minimum time for alarm may be set to prevent alarms on brief events.
Unused channels may be disabled to exclude them from total and average calculations.

2

North America: Temperature -30º – 70ºc, 0 – 95% humidity, non-condensing.
Altitude up to 2000M.
For indoor and outdoor use when used in an appropriate enclosure.
The A90DC-12 must be mounted inside a NEMA rated electrical enclosure for safety and isolation
requirements.

File: E320540 (Model3 A90DC-12, A90DC-10)

Measurement Category IV applications2 (Cat IV):

up to 600vdc Pollution Degree 2: no insulation required
up to 1000vdc Pollution Degree 3: with basic insulation (wire insulation must be rated to 1000v)

1

Outputs are intended for low voltage class 2 inputs.

2

If the product is used in a manner not specified by the manufacture, the protection provided by the equipment may be

impaired.

3

Note: The A90DC-12 or A90DC-10 models are identical except for the number of DC current sensor channels present on
the device. This manual will refer to model A90DC-12 however the manual covers installation and operation for all three
models except where otherwise noted.

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