CCS WattNode WNC-3Y-208-MB User manual

Rev 1.18c
(M7)
WattNode Modbus
Models
●WNC-3Y-208-MB
●WNC-3Y-400-MB
●WNC-3Y-480-MB
●WNC-3Y-600-MB
●WNC-3D-240-MB
●WNC-3D-400-MB
●WNC-3D-480-MB
WattNode Revenue for
Modbus Models
●RWNC-3Y-208-MB
●RWNC-3Y-400-MB
●RWNC-3Y-480-MB
●RWNC-3Y-600-MB
●RWNC-3D-240-MB
●RWNC-3D-400-MB
●RWNC-3D-480-MB
WattNode®Modbus
Installation and Operation Manual
Test Equipment Depot - 800.517.8431 - 5 Commonwealth Ave, Woburn MA 01801 - TestEquipmentDepot.com

2
This equipment has been tested and complies with the limits for a Class B digital device, pursu-
ant to part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This
device may not cause harmful interference, and (2) this device must accept any interference
received, including interference that may cause undesired operation.
The FCC limits are designed to provide reasonable protection against harmful interference in a
residential installation. This equipment generates, uses and can radiate radio frequency energy
and, if not installed and used in accordance with the instructions, may cause harmful interfer-
ence to radio communications. However, there is no guarantee that interference will not occur in
a particular installation. If this equipment does cause harmful interference to radio or television
reception, which can be determined by turning the equipment off and on, the user is encouraged
to try to correct the interference by one or more of the following measures:
●Reorient or relocate the receiving antenna.
●Increase the separation between the equipment and receiver.
●Connect the equipment into an outlet on a circuit different from that to which the receiver is
connected.
●Consult the dealer or an experienced radio/TV technician to help.

Contents 3
Contents
Overview ................................................................................................................................5
Measurements ................................................................................................................................ 5
Communication ............................................................................................................................... 5
Diagnostic LEDs .............................................................................................................................. 5
Options ........................................................................................................................................... 5
Current Transformers....................................................................................................................... 6
Additional Literature......................................................................................................................... 6
Front Label ...................................................................................................................................... 7
Installation .............................................................................................................................9
Precautions ..................................................................................................................................... 9
Electrical Service Types ..................................................................................................................10
Single-Phase Two-Wire with Neutral .........................................................................................10
Single-Phase Three-Wire (Mid-Point Neutral) ............................................................................11
Single-Phase Two-Wire without Neutral....................................................................................12
Three-Phase Four-Wire Wye.....................................................................................................13
Three-Phase Three-Wire Delta Without Neutral.........................................................................14
Three-Phase Four-Wire Delta (Wild Leg) ...................................................................................14
Grounded Leg Service .............................................................................................................14
Mounting........................................................................................................................................15
Selecting Current Transformers ......................................................................................................16
Connecting Current Transformers ...................................................................................................17
Circuit Protection............................................................................................................................18
Connecting Voltage Terminals.........................................................................................................19
Setting the Modbus Address ..........................................................................................................19
Baud Rate............................................................................................................................... 20
Connecting Modbus Outputs......................................................................................................... 20
Planning the Modbus Network ................................................................................................ 20
Installation Summary ..................................................................................................................... 22
Wiring ..................................................................................................................................... 22
Installation LED Diagnostics........................................................................................................... 23
Other Fixed Pattern ................................................................................................................. 25
Measurement Troubleshooting....................................................................................................... 25
Modbus Communication Diagnostics ............................................................................................ 28
Operating Instructions.........................................................................................................30
Quick Start.................................................................................................................................... 30
WattNode Basic Configuration ................................................................................................ 30
Verify Operation ...................................................................................................................... 30
Measurement Overview............................................................................................................31
Modbus Communication ................................................................................................................31
Modbus Functions ...................................................................................................................31
Modbus Register Lists................................................................................................................... 32
Modbus Register Addressing .................................................................................................. 32
Report Slave ID ....................................................................................................................... 32
Floating Point and Integer Registers ........................................................................................ 33
Reading and Writing 32 Bit Registers ...................................................................................... 33
Basic Register List - Floating Point .......................................................................................... 34
Basic Register List - Integer..................................................................................................... 34
Advanced Register List - Floating Point ................................................................................... 35

4 Contents
Advanced Register List - Integer.............................................................................................. 36
Configuration Register List .......................................................................................................37
Communication Register List................................................................................................... 38
Diagnostic Register List........................................................................................................... 38
Option Information Registers ................................................................................................... 39
Custom Register Map ............................................................................................................. 39
Basic Registers ............................................................................................................................. 40
Energy Registers ..................................................................................................................... 40
Power Registers...................................................................................................................... 40
Voltage Registers .....................................................................................................................41
Frequency ................................................................................................................................41
Advanced Registers .......................................................................................................................41
Per-Phase Energy Registers .....................................................................................................41
Positive Energy.........................................................................................................................41
Negative Energy...................................................................................................................... 42
Reactive Energy ...................................................................................................................... 42
Apparent Energy ..................................................................................................................... 42
Power Factor........................................................................................................................... 42
Reactive Power ....................................................................................................................... 43
Apparent Power ...................................................................................................................... 43
Current.................................................................................................................................... 44
Demand.................................................................................................................................. 44
I/O Pin Options........................................................................................................................ 46
Configuration Registers ................................................................................................................. 46
Demand Configuration ............................................................................................................ 48
Zeroing Registers .................................................................................................................... 49
I/O Pin Options Configuration .................................................................................................. 50
Communication Registers.............................................................................................................. 50
Diagnostic Registers.......................................................................................................................51
Error Codes................................................................................................................................... 52
Maintenance and Repair................................................................................................................ 54
Specifications ......................................................................................................................55
Models .......................................................................................................................................... 55
Model Options ........................................................................................................................ 55
Accuracy................................................................................................................................. 56
Measurement ................................................................................................................................ 57
Modbus Communication ............................................................................................................... 57
Electrical ....................................................................................................................................... 58
Certifications ................................................................................................................................. 59
Environmental................................................................................................................................ 59
Mechanical.................................................................................................................................... 59
Current Transformers..................................................................................................................... 59
Warranty...............................................................................................................................60
Limitation of Liability ...................................................................................................................... 60

Overview 5
Overview
Congratulations on your purchase of the WattNode®Modbus®watt/watt-hour transducer (meter).
The WattNode meter offers precision energy and power measurements in a compact pack-
age. It enables you to make power and energy measurements within existing electric service
panels avoiding the costly installation of subpanels and associated wiring. It is designed for use
in demand side management (DSM), sub-metering, and energy monitoring applications. The
WattNode meter communicates on an EIA RS-485 two-wire bus using the Modbus protocol.
Models are available for single-phase, three-phase wye, and three-phase delta configurations for
voltages from 120 VAC to 600 VAC at 50 and 60Hz.
Measurements
The WattNode Modbus meter measures the following:
●True RMS Power - Watts (Phase A, Phase B, Phase C, Sum)
●Reactive Power - VARs (Phase A, Phase B, Phase C, Sum)
●Power Factor (Phase A, Phase B, Phase C, Average)
●True RMS Energy - Watthours (Phase A, Phase B, Phase C, Sum)
●Reactive Energy - VAR-hours (Sum)
●AC Frequency
●RMS Voltage (Phase A, Phase B, Phase C)
●RMS Current (Phase A, Phase B, Phase C)
●Demand and Peak Demand
One WattNode Modbus meter can measure up to three different “single-phase two-wire with
neutral” branch circuits from the same service by separately monitoring the phase A, B, and C
values. If necessary, you can use different CTs on the different circuits.
Communication
The WattNode meter uses a half-duplex EIA RS-485 interface for communication. The standard
baud rates are 9,600 and 19,200 baud, and rates from 1,200 to 38,400 baud can be configured.
The meter uses the industry standard Modbus RTU (binary) communication protocol, allowing
up to 127 devices per RS-485 subnet. The WattNode meter can auto-detect RS-485 polarity on
properly biased networks, simplifying installation.
There are numerous low-cost RS-485 interfaces to PCs, using both USB and serial ports. There
are many PC programs and standalone devices for collecting and recording Modbus data.
Diagnostic LEDs
The meter includes three power diagnostic LEDs—one per phase. During normal operation,
these LEDs flash on and off, with the speed of flashing roughly proportional to the power on each
phase. The LEDs flash green for positive power and red for negative power. Other conditions are
signaled with different LED patterns. See Installation LED Diagnostics (p. 23)for details.
The Modbus WattNode meter includes a communication LED that lights green, yellow, or red to
diagnose the RS-485 network. See Modbus Communication Diagnostics (p. 28)for details.
Options
The WattNode Modbus meter can be ordered with several options. For more details and docu-
mentation, see article WattNode Modbus - Options on our website.
General Options
●Option CT=xxx - Pre-assign xxx as the global CtAmps value.

6 Overview
●Option CT=xxx/yyy/zzz - Pre-assign xxx to CtAmpsA, yyy to CtAmpsB, and zzz to
CtAmpsC.
Communication Options
●Option EP - Factory configure the Modbus RS-485 communications to even parity (E81).
●Option 19K - Factory configure the RS-485 communications 19,200 baud. Position 8 of the
DIP switch will be ignored.
●Option 38K - Factory configure the RS-485 communications to 38,400 baud. Position 8 of
the DIP switch will be ignored.
●Option TCP‑RTU - Configure the communications to the Modbus TCP-RTU protocol option
for use with RS-485 to Ethernet gateways (serial device adapters).
●Option AD - Factory configure the Modbus address. The DIP switch address will be ignored.
X Terminal Options
These options utilize the X(auxiliary) terminal on the MODBUS connector. Only one of these can
be ordered on any single meter.
●Option X5 - Provides 5 VDC at up to 60 milliamps between the C(common) and X(5 V)
terminals.
●Option IO - Provides a digital input (level sensing and pulse counting) or output (for load
shedding and other applications) on the Xterminal.
●Option SSR - Provides a solid-state relay (contact closure) output between the Xand C
terminals for load shedding and other applications.
Special Options
Contact the factory about the following special options:
●Option 232 - Provide RS-232 I/O in place of RS-485.
●Option TTL - Provide 5 V TTL UART I/O in place of RS-485.
Current Transformers
The WattNode meter uses solid-core (toroidal), split-core (opening), and bus-bar style current
transformers (CTs) with a full-scale voltage output of 0.33333 Vac. Split-core and bus-bar CTs
are easier to install without disconnecting the circuit being measured. Solid-core CTs are more
compact, generally more accurate, and less expensive, but installation requires that you discon-
nect the circuit to install the CTs.
Additional Literature
These additional documents are available on the Continental Control Systems, LLC website or
Modbus.org website.
●WattNode Modbus - Quick Install Guide
●WattNode Modbus Register List (Excel format): WNC-Modbus-Register-List-V18.xls
●Continental Control Systems, LLC website
○http://www.ccontrolsys.com/w/WattNode_Modbus - main page.
○http://www.ccontrolsys.com/w/Category:WattNode_Modbus - support articles.
●http://www.modbus.org/specs.php
○Modbus Application Protocol Specification - V1.1b
○Modbus over Serial Line - Specification & Implementation Guide - V1.0

10 Installation
Electrical Service Types
Below is a list of service types, with connections and recommended models. Note: the ground
connection improves measurement accuracy, but is not required for safety.
Electrical
Service (or Load) Types
Line-to-
Neutral (Vac)
Line-to-
Line
(Vac)
Meter
Service
Type
Meter
Powered by
1 Phase 2 Wire 120V with neutral 96 – 138 n.a. 3Y-208 Nand ØA
1 Phase 2 Wire 230V with neutral
(non-U.S.)
184 – 264 n.a. 3Y-400 Nand ØA
1 Phase 2 Wire 277V with neutral 222 – 318 n.a. 3Y-480 Nand ØA
1 Phase 2 Wire 208V no neutral n.a. 166 – 276 3D-240 ØAand ØB
1 Phase 2 Wire 240V no neutral n.a. 166 – 276 3D-240 ØAand ØB
1 Phase 3 Wire 120V/240V with
neutral 96 – 138 166 – 276 3Y-208 Nand ØA
3D-240 ØAand ØB
3 Phase 3 Wire Delta 208V no neutral n.a. 166 – 276 3D-240 ØAand ØB
3 Phase 3 Wire Delta 400V no neutral
(non-U.S.) n.a. 320 – 460 3D-400 ØAand ØB
3 Phase 3 Wire Delta 480V no neutral n.a. 384 – 552 3D-480 ØAand ØB
3 Phase 4 Wire Wye 120V/208V with
neutral 96 – 138 166 – 276 3Y-208 Nand ØA
3D-240 ØAand ØB
3 Phase 4 Wire Delta 120/208/240V
with neutral 96 – 138 166 – 276 3D-240 ØAand ØB
3 Phase 4 Wire Wye 230V/400V with
neutral (non-U.S.) 184 – 264 320 – 460 3Y-400 Nand ØA
3D-400ØAand ØB
3 Phase 4 Wire Wye 277V/480V with
neutral 222 – 318 384 – 552 3Y-480 Nand ØA
3D-480 ØAand ØB
3 Phase 4 Wire Delta 240/415/480V
with neutral 222 – 318 384 – 552 3D-480 ØAand ØB
3 Phase 4 Wire Wye 347V/600V with
neutral 278 – 399 480 – 690 3Y- 60 0 Nand ØA
Table 1: WattNode Models
Single-Phase Two-Wire with Neutral
This configuration is most often seen in homes and offices. The two conductors are neutral and
line. For these models, the meter is powered from the Nand ØAterminals.
Figure 2: Single-Phase Two-Wire Connection
Ground
WHITE
BLACK
ØB CT
ØC CT
ØA CT
ØB
ØC
N
ØA
Common
B+, D1, RxD+/TxD+
EIA-485
Monitoring Device
A−, D0, RxD−/TxD−
Continental Control Systems LLC
Status
Status
Status
X
C
B+
A
MODBUS
Com
WNC-
WATTNODE
®
MODBUS
-MB
Line
Neutral
LINE
LOAD
Shorting
Jumpers
Source
Face
Current
Transformer
3Y-xxx
Test Equipment Depot - 800.517.8431 - 5 Commonwealth Ave, Woburn MA 01801 - TestEquipmentDepot.com