281E ArmorStart: Catalog Decoding, Wiring, EtherNet/IP & Installation Guide
Contents
1. What Is the 281E ArmorStart?
The ArmorStart EtherNet/IP Distributed Motor Controllers are integrated, pre-engineered motor-starting solutions that mount on the machine rather than in a central control panel. The family spans three bulletins that share the same IP67/UL Type 4/12 enclosure, 24V DC control architecture, embedded dual-port EtherNet/IP switch, and four-input / two-output I/O section — but differ in how they control the motor.
| Bulletin | Starting Method | Motor Range | Operational Voltage |
|---|---|---|---|
| 280E | Full-Voltage (across-the-line) | 0.5–10 Hp (0.37–7.5 kW) | 200…480V AC |
| 281E | Full-Voltage Reversing | 0.5–10 Hp (0.37–7.5 kW) | 200…480V AC |
| 284E | Sensorless Vector Control (VFD) | 0.5–5 Hp (0.4–3.0 kW) | 380…480V AC |
The 281E is the reversing starter. It offers full-voltage starting for reversing applications — meaning it can run a three-phase motor in both forward and reverse directions, where full inrush current and locked-rotor torque are realized at start. This distinguishes it from the 280E (full-voltage, single-direction) and the 284E (variable-frequency drive with sensorless vector control for precise speed regulation).
The Distributed Motor Control Concept
The ArmorStart is a modular “plug and play” (PnP) design built for on-machine mounting. Quick disconnects for the I/O, communications, and motor connections reduce wiring time and minimize wiring errors. A UL Listed disconnect is built in, which in many applications eliminates the need for additional components. The controller offers four configurable (sink/source) DC inputs and two sourcing solid-state outputs as standard, so local sensors and actuators can be wired directly at the device for monitoring and controlling the application process.
Standard, integrated features of every 281E include:
- Built-in UL Listed disconnect — lockable local disconnect with hasp provision (recommend 8 mm / 5/16 in. lock shackle).
- Electronic motor overload protection — I²t algorithm, programmable over the network, selectable trip class.
- Embedded dual-port EtherNet/IP switch — supports Device Level Ring (DLR) and linear topologies.
- Four 24V DC configurable inputs and two sourcing solid-state outputs on M12 connectors.
- Embedded web server for status, diagnostics, configuration, and SMTP e-mail alerts.
- DeviceLogix — stand-alone Boolean logic (AND, OR, NOT, Timers, Counters, Latches) that runs in the device, independent of the network.
- Optional Hand-Off-Auto (HOA) keypad for local start/stop control.
2. 281E Catalog Number Decoder
The 281E catalog number is read position-by-position. The breakdown below follows Figure 1 (Catalog Number Explanation for 280E, 281E) in publication 280E-UM001. Rockwell notes that this explanation is for reference only and should not be used for product selection, because not all combinations produce a valid catalog number.
| Position | Code | Meaning |
|---|---|---|
| a — Bulletin Number | 281 | Reversing Starter |
| b — Communications | E | EtherNet/IP |
| c — Enclosure Type | F | IP67 / UL Type 4/12 |
| d — Contactor Size / Control Voltage | 12Z | 24V DC (smaller contactor frame) |
| d — Contactor Size / Control Voltage | 23Z | 24V DC (larger contactor frame) |
| e — Short Circuit Protection | 10 | 10 A Rated Device |
| e — Short Circuit Protection | 25 | 25 A Rated Device |
| f — Overload Selection Current Range | A | 0.24…1.2 A |
| f — Overload Selection Current Range | B | 0.5…2.5 A |
| f — Overload Selection Current Range | C | 1.1…5.5 A |
| f — Overload Selection Current Range | D | 3.2…16 A |
| g — Connection / Media | CR | Conduit control power / Conduit 3-phase / 3 m unshielded cordset |
| g — Connection / Media | DR | Conduit daisy-chain control / Conduit daisy-chain 3-phase / 3 m unshielded cordset |
| g — Connection / Media | RR | Round Media (male receptacle) control / Round Media 3-phase / 3 m unshielded cordset |
| h — Option 1 | 3 | Hand/Off/Auto Selector Keypad |
| h — Option 1 | 3FR | Hand/Off/Auto Selector Keypad with Forward/Reverse |
Note: The 10 A / overload-code-A rating (e.g. -10A-) corresponds to a 0.24…1.2 A overload current range, which Rockwell's selection table rates at roughly 0.37 kW (0.5 Hp @ 460V) at the bottom of the 281E reversing-starter range.
3. Power & Control Wiring
The 281E brings three-phase line power, 24V DC control power, and ground into the device, then feeds the motor out through a quick-disconnect cordset. The terminal designations below apply to the Bulletin 280E, 281E, and 284E and are accessed by removing the terminal access cover plate.
Power, Control, and Ground Terminals
| Terminal | Poles | Description |
|---|---|---|
| A1 (+) | 2 | Control Power Input (switched +V) |
| A2 (–) | 2 | Control Power Common (–V for switched and unswitched) |
| A3 (+) | 2 | Unswitched 24V Control |
| PE | 2 | Ground |
| 1/L1 | 2 | Line Power Phase A |
| 3/L3 | 2 | Line Power Phase B |
| 5/L5 | 2 | Line Power Phase C |
Switched vs. Unswitched Control Power
The 281E accepts 24V DC (–15%, +10%) control power and uses it for both communications and I/O. The control power architecture splits into a switched and an unswitched rail:
- A1 = Switched +V. Supplies power to the ArmorStart outputs. Removing this power, or placing the disconnect in the OFF position, disables the outputs.
- A2 = Common (–V). Shared common for both the switched and unswitched rails. A2 should be grounded at the voltage source.
- A3 = Unswitched +V. Supplies logic power, sensor inputs, and the communication module. This rail is not affected by the disconnect, so the input states stay valid and the device can communicate whenever A3 power is present.
Wire Size and Torque
Each power, control, and ground terminal accepts a maximum of two wires per terminal.
| Terminal Group | Wire Size | Torque | Strip Length |
|---|---|---|---|
| Power and Ground — Primary terminal | 1.5…4.0 mm² (#16…#10 AWG) | 10.8 lb·in (1.2 N·m) | 0.35 in. (9 mm) |
| Power and Ground — Secondary terminal | 1.5…4.0 mm² (#16…#10 AWG) | 4.5 lb·in (0.5 N·m) | 0.35 in. (9 mm) |
| Control Inputs | 1.0…4.0 mm² (#18…#10 AWG) | 6.2 lb·in (0.7 N·m) | 0.35 in. (9 mm) |
Three Power-Entry Methods (Gland Plate)
The ArmorStart offers three ways to bring incoming three-phase and control power into the device:
- Conduit entrance — traditional 0.75 in. and 1 in. conduit hole openings.
- Daisy chain (feed-through) power — reduces the need for additional components such as junction boxes.
- ArmorConnect power media — factory-installed receptacles provide quick-connect connectivity for both three-phase and control power media. ArmorConnect power and control media are detailed in publication 280PWR-SG001.
Motor Cable
A 3-meter unshielded 4-conductor cordset is provided with each unit as standard. The motor connection is a quick-disconnect cordset, so the motor leads do not have to be hard-wired at the controller.
4. Integrated I/O: Four Inputs, Two Outputs
The EtherNet/IP 281E includes four DC inputs and two solid-state outputs on M12 connectors, letting you wire local sensors and actuators directly at the machine instead of running them back to a remote I/O rack.
Inputs
Four 24V DC inputs, single keyed, two inputs per connector, on two M12 connectors. The inputs are sourced from A3/A2 control power (the unswitched rail) and are software-configurable as sinking or sourcing. Each input has an LED status indication.
Outputs
Two self-protected solid-state outputs, single keyed, one per connector, on one M12 connector each. The outputs are sourcing type with a maximum current per output point of 0.5 A DC, sourced from A1/A2 control power (the switched rail). Each output has an LED status indication.
| I/O Attribute | Value |
|---|---|
| Inputs | 4 fixed, two per M12 connector, sink/source software selectable |
| Input on-state voltage range | 10–26V DC |
| Input rated operation voltage | 24V DC |
| Input source | A3/A2 unswitched control power |
| Outputs | 2 sourcing solid-state, one per M12 connector |
| Output max current per point | 0.5 A DC |
| Output total current (both points) | Not to exceed 1.0 A total |
| Output source | A1/A2 switched control power |
| Connector style | 5-pin female M12 (Micro) |
5. EtherNet/IP Setup & Configuration
The 281E communicates over EtherNet/IP through an embedded dual-port switch, so it can be daisy-chained into a linear or Device Level Ring (DLR) network without an external switch at each device.
Dual-Port Switch and DLR
The ArmorStart EtherNet/IP controller includes a dual-port Ethernet switch supporting 10/100 Mbps, using a sealed D-coded micro (M12) style Ethernet connector. The embedded switch lets end devices form linear and ring topologies and supports the DLR protocol. It also supports IEEE 1588 transparent clock for CIP Motion and CIP Sync applications, and supports QoS and IGMP for managing network traffic.
Setting the IP Address
The IP address can be set three ways: via the rotary network address switches on the I/O section of the device, dynamically via DHCP, or via the embedded web server. DHCP is enabled as the factory default, and the rotary switches ship set to 999.
- Rotary address switches. Three rotary switches on the front of the I/O module set the host octet. Remove the protective IP67 caps, then set a valid value of 1…254. When set to a valid number, the IP address becomes 192.168.1.[switch setting]. There is a writable surface near the switches for noting the IP address.
- DHCP. If DHCP is preferred, use the Rockwell Automation BootP/DHCP utility (version 2.3 or later, shipped with RSLogix 5000 / RSLinx) or a third-party DHCP server.
- Embedded web server. The IP address can also be configured dynamically or statically through the embedded web server.
Embedded Web Server and E-mail Alerts
The embedded web server lets you view information and configure the controller from a standard web browser. The default login is “Administrator” with no password set by default — set a unique password for authorized personnel. The web server also supports SMTP, so the controller can e-mail specific fault/trip messages to the user once configured.
Studio 5000 / RSLogix 5000 Integration
An Add-On Profile (AOP) for ControlLogix is available; it streamlines programming and installation by eliminating the task of individually configuring device tags, and supports copy-and-paste configuration across multiple ArmorStart controllers. RSLogix 5000 revision 17.01 or later is required for AOP support. Each ArmorStart EtherNet/IP controller consumes one CIP connection (a Class 3 connection when the AOP is displayed). For configuration tools such as RSNetWorx for EtherNet/IP and data servers such as RSLinx Classic, an Electronic Data Sheet (EDS) is available and can be uploaded directly from the device via the web server.
6. Protection & Diagnostics
Electronic motor overload protection is standard on every 281E. The overload is accomplished electronically with an I²t algorithm, is programmable over the communication network, and is ambient-insensitive by design.
Overload Trip Class
On the 280E and 281E, the overload trip class can be selected for Class 10, 15, or 20 protection. (By contrast, the 284E VFD variant is Class 10 only.) The trip rating is 120% of the Full Load Current (FLC) setting, and protection is three-pole.
| Overload Attribute | Value |
|---|---|
| Trip classes | 10, 15, 20 (selectable) |
| Trip rating | 120% of FLC setting |
| Number of poles | 3 |
| Overload current range — code A | 0.24…1.2 A |
| Overload current range — code B | 0.5…2.5 A |
| Overload current range — code C | 1.1…5.5 A |
| Overload current range — code D | 3.2…16 A |
Protection Faults (Trips)
Protection faults are generated when potentially dangerous or damaging conditions are detected. The 280E/281E trip set includes:
- Short Circuit
- Overload
- Phase Loss
- Control Pwr Loss
- Input Fault
- Over Temperature
- Phase Imbalance
- A3, Unswitched Power Loss
- EEprom
- Hdw Flt
Note: Parameter group “Start Protection,” Parameter 24 “PrFault Enable,” enables and disables the protection faults; Parameter 61 “LastPR Fault” records the last protection fault.
Status LEDs
Diagnostics are surfaced through two LED groups plus a local reset button. The Control Module group has four status LEDs and a Reset button; the EtherNet/IP group has four LEDs.
| LED | Group | Indication |
|---|---|---|
| POWER | Control Module | Solid green when switched (+A1/A2) control power is present with proper polarity |
| RUN | Control Module | Solid green when a start command and control power are present |
| NETWORK | Control Module | Bicolor red/green — status of the internal communication link |
| FAULT | Control Module | Indicates a controller fault (trip) condition |
| Link1 Activity/Status (Port 1) | EtherNet/IP | Bicolor green/yellow — Ethernet link/activity |
| Link2 Activity/Status (Port 2) | EtherNet/IP | Bicolor green/yellow — Ethernet link/activity |
| MOD | EtherNet/IP | Bicolor red/green — Ethernet module status |
| NET | EtherNet/IP | Bicolor red/green — Ethernet network status |
Note: The Reset button on the Control Module is a local trip reset.
7. Installation & Environmental Ratings
The 281E is designed for on-machine mounting in harsh environments. Its IP67/UL Type 4/12 enclosure is rated for water wash-down areas, and the integrated disconnect is lockable for maintenance lock-out.
Mounting Orientation
The recommended mounting orientation is the vertical configuration. This allows proper airflow over the heat sink. Improper mounting or debris build-up reduces airflow and increases internal temperatures, which may reduce the overall life of the product. For alternate mounting, contact your local Rockwell sales representative.
Disconnect Lock-Out
The built-in disconnect provides for lock-out: Rockwell recommends an 8 mm (5/16 in.) lock shackle or hasp, and the hasp should not exceed 8 mm (5/16 in.) when closed. Always open the disconnect switch before connecting or disconnecting cables to preserve the enclosure shock and environment rating.
Environmental & Electrical Specifications
| Specification | Value |
|---|---|
| Enclosure rating | NEMA 4/12 (UL) / IP67 (IEC) |
| Operating temperature range | –20…40 °C (–4…104 °F) |
| Storage and transportation temperature | –25…85 °C (–13…185 °F) |
| Altitude | 2000 m |
| Humidity | 5…95% (non-condensing) |
| Pollution degree | 3 |
| Resistance to shock — operational | 15 G |
| Resistance to shock — non-operational | 30 G |
| Resistance to vibration — operational | 1 G, 0.15 mm (0.006 in.) displacement |
| Resistance to vibration — non-operational | 2.5 G, 0.38 mm (0.015 in.) displacement |
| Approximate shipping weight (12-frame) | 10.4 kg (23 lb) |
| Control voltage | 24V DC (+10%, –15%) |
| Power circuit rated operation voltage | 200…575V |
| Power circuit rated insulation voltage | 600V |
| Operating frequency | 50/60 Hz |
Conduit / Cord Grip Hole Sizes
When using conduit or cord-grip entry, the gland plate must be punched to the correct hole diameter:
| Conduit/Cord Size | Actual Hole Diameter |
|---|---|
| 0.50 in. (16 mm) | 0.885 in. (22.48 mm) |
| 0.75 in. (21 mm) | 1.115 in. (28.32 mm) |
| 1.00 in. (27 mm) | 1.362 in. (34.59 mm) |
| 1.25 in. (35 mm) | 1.701 in. (43.21 mm) |
| 1.50 in. (41 mm) | 1.948 in. (49.48 mm) |
Standards & Certifications
The 281E EtherNet/IP controller is certified to: cULus (File No. E3125, Guides NLDX, NLDX7); UL 508; CSA C22.2 No. 14; EN/IEC 60947-4 and 60947-4-1; CE Marked per Low Voltage Directive 2006/95/EC and EMC Directive 2004/108/EC; CCC; and ODVA for EtherNet/IP.
8. Related ArmorStart Catalogs & Guides
The 281E sits within a broader ArmorStart EtherNet/IP family. When specifying or replacing a unit, these related bulletins and references are useful:
- Bulletin 280E — full-voltage (single-direction) ArmorStart starter. Same enclosure, I/O, and EtherNet/IP architecture as the 281E, without reversing.
- Bulletin 284E — variable-frequency ArmorStart with sensorless vector control (PowerFlex 40 based), 0.5–5 Hp at 380…480V AC, for precise speed control. Adds options such as DB brake connector, source brake contactor, output contactor, and EMI filter.
- ArmorConnect Power & Control Media (280PWR-SG001) — the quick-connect three-phase and control power media that the RR/DR connection codes plug into.
- Hand-Off-Auto (HOA) keypad option — Option-1 code 3 (HOA) or 3FR (HOA with Forward/Reverse), for local start/stop control directly on the 281E.
For complete technical data on all ArmorStart EtherNet/IP controllers, refer to Rockwell Automation publication 280E-UM001, ArmorStart Distributed Motor Controller with EtherNet/IP User Manual.
Reference Documentation
The following Rockwell Automation publications were used as references for this guide. These are the official manufacturer documents for the hardware covered in this article.
| Publication | Description | Download |
|---|---|---|
| 280E-UM001 | ArmorStart 280E/281E/284E Distributed Motor Controller with EtherNet/IP User Manual | |
| 280ES-TD001 | ArmorStart ST Distributed Motor Controller Technical Data (reference for shared family specifications) |
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