1794-OM8 | Allen Bradley FLEX I/O Digital AC Output Module
The Allen Bradley 1794-OM8 is a FLEX I/O digital AC output module designed to switch external AC field devices through eight nonisolated output channels. It provides a nominal 240V AC output rating, with a maximum current of 500 mA per channel and 4.0 A per module. The module interfaces with the FLEX I/O terminal bus and supports installation on compatible terminal base units.
Technical Specifications
| Parameter | Specification |
|---|---|
| Model | 1794-OM8 |
| Brand | Allen Bradley |
| Product Type | FLEX I/O Digital AC Output Module |
| Product Line | FLEX I/O 1794 |
| Part Number | 1794-OM8 |
| UPC | 612598179978 |
| Number of Outputs | 8 |
| Output Type | Nonisolated AC |
| Nominal Output Voltage | 240V AC |
| On-State Output Voltage Range | 159-264V AC |
| Output Current Rating | 4.0 A per module |
| Maximum On-State Current | 500 mA per output |
| Minimum On-State Current | 5 mA per output at 55 deg C |
| Maximum On-State Voltage Drop | 1.5V AC at 0.5 A |
| Maximum Off-State Leakage Current | 2.5 mA |
| Isolation Voltage | 250V continuous |
| Flexbus Current | 60 mA at 5V DC |
| Maximum Power Dissipation | 5 W at 0.5 A |
| Maximum Thermal Dissipation | 17.1 BTU/hr at 0.5 A |
| Operating Temperature | 0 to 55 deg C (32 to 131 deg F) |
| Relative Humidity | 5-95%, noncondensing |
| Compatible Terminal Bases | 1794-TBNF, 1794-TBN |
| Mounting | DIN rail |
| Weight | 1.88 lbs (0.85 kg) |
Output Configuration and Electrical Characteristics
The 1794-OM8 provides eight nonisolated AC output channels for controlling external field loads. Each output supports a maximum on-state current of 500 mA, while the total module current rating is 4.0 A when all eight channels operate at their maximum rated current.
The specified on-state voltage range is 159-264V AC. The maximum voltage drop is 1.5V AC at 0.5 A, and off-state leakage current is limited to 2.5 mA. These values should be considered when checking the electrical requirements of connected loads, particularly devices that may respond to small residual currents.
FLEX I/O Terminal Bus and Installation
The module is fitted to a compatible FLEX I/O terminal base unit, establishing the connection between the field wiring and the I/O bus. Supported terminal base models listed for the 1794-OM8 are 1794-TBNF and 1794-TBN.
Installation uses a DIN rail mounting arrangement. The terminal base provides the field wiring interface, while the removable I/O module connects through the terminal bus.
Status Indication and System Integration
The supplied product description identifies 16 yellow LED status indicators associated with channel status and output signals. These indicators provide visual information for checking module and field output conditions during maintenance.
The FLEX I/O platform supports communication through ControlNet, DeviceNet, EtherNet/IP, and Universal Remote I/O, depending on the selected adapter and system configuration. These communication options relate to the overall FLEX I/O system rather than independent network interfaces on the 1794-OM8 itself.
Electrical Loading and Thermal Considerations
The module has a maximum power dissipation of 5 W at 0.5 A and a thermal dissipation rating of 17.1 BTU/hr under the same stated condition. The Flexbus current requirement is 60 mA at 5V DC.
The 0-55 deg C operating temperature range and 5-95% noncondensing relative humidity specification define the stated environmental operating conditions. Actual output loading should remain within both the individual channel limit and the total module rating.
Frequently Asked Questions
Q: How many output channels does the Allen Bradley 1794-OM8 have?
A: The 1794-OM8 has eight nonisolated AC output channels. Each channel supports up to 500 mA, with a maximum total module current rating of 4.0 A.
Q: Which terminal base units are compatible with the 1794-OM8?
A: The listed compatible terminal bases are 1794-TBNF and 1794-TBN. The terminal base provides the field wiring connection and interface to the FLEX I/O bus.
Q: Can the 1794-OM8 be removed while the system is powered?
A: The supplied product description states that FLEX I/O modules can be inserted or removed under power because the I/O module has no direct field wiring connection. However, confirm the applicable system configuration and installation procedures before performing live replacement.
Q: What is the difference between the 1794-OM8 output rating and its module current rating?
A: The 500 mA rating applies to each individual output, while 4.0 A represents the maximum combined current rating for all eight outputs. Both limits must be observed when configuring connected loads.
1794-OM8 | Allen Bradley FLEX I/O Digital AC Output Module
1794-OM8 | Allen Bradley FLEX I/O Digital AC Output Module
The Allen Bradley 1794-OM8 is a FLEX I/O digital AC output module designed to switch external AC field devices through eight nonisolated output channels. It provides a nominal 240V AC output rating, with a maximum current of 500 mA per channel and 4.0 A per module. The module interfaces with the FLEX I/O terminal bus and supports installation on compatible terminal base units.
Technical Specifications
| Parameter | Specification |
|---|---|
| Model | 1794-OM8 |
| Brand | Allen Bradley |
| Product Type | FLEX I/O Digital AC Output Module |
| Product Line | FLEX I/O 1794 |
| Part Number | 1794-OM8 |
| UPC | 612598179978 |
| Number of Outputs | 8 |
| Output Type | Nonisolated AC |
| Nominal Output Voltage | 240V AC |
| On-State Output Voltage Range | 159-264V AC |
| Output Current Rating | 4.0 A per module |
| Maximum On-State Current | 500 mA per output |
| Minimum On-State Current | 5 mA per output at 55 deg C |
| Maximum On-State Voltage Drop | 1.5V AC at 0.5 A |
| Maximum Off-State Leakage Current | 2.5 mA |
| Isolation Voltage | 250V continuous |
| Flexbus Current | 60 mA at 5V DC |
| Maximum Power Dissipation | 5 W at 0.5 A |
| Maximum Thermal Dissipation | 17.1 BTU/hr at 0.5 A |
| Operating Temperature | 0 to 55 deg C (32 to 131 deg F) |
| Relative Humidity | 5-95%, noncondensing |
| Compatible Terminal Bases | 1794-TBNF, 1794-TBN |
| Mounting | DIN rail |
| Weight | 1.88 lbs (0.85 kg) |
Output Configuration and Electrical Characteristics
The 1794-OM8 provides eight nonisolated AC output channels for controlling external field loads. Each output supports a maximum on-state current of 500 mA, while the total module current rating is 4.0 A when all eight channels operate at their maximum rated current.
The specified on-state voltage range is 159-264V AC. The maximum voltage drop is 1.5V AC at 0.5 A, and off-state leakage current is limited to 2.5 mA. These values should be considered when checking the electrical requirements of connected loads, particularly devices that may respond to small residual currents.
FLEX I/O Terminal Bus and Installation
The module is fitted to a compatible FLEX I/O terminal base unit, establishing the connection between the field wiring and the I/O bus. Supported terminal base models listed for the 1794-OM8 are 1794-TBNF and 1794-TBN.
Installation uses a DIN rail mounting arrangement. The terminal base provides the field wiring interface, while the removable I/O module connects through the terminal bus.
Status Indication and System Integration
The supplied product description identifies 16 yellow LED status indicators associated with channel status and output signals. These indicators provide visual information for checking module and field output conditions during maintenance.
The FLEX I/O platform supports communication through ControlNet, DeviceNet, EtherNet/IP, and Universal Remote I/O, depending on the selected adapter and system configuration. These communication options relate to the overall FLEX I/O system rather than independent network interfaces on the 1794-OM8 itself.
Electrical Loading and Thermal Considerations
The module has a maximum power dissipation of 5 W at 0.5 A and a thermal dissipation rating of 17.1 BTU/hr under the same stated condition. The Flexbus current requirement is 60 mA at 5V DC.
The 0-55 deg C operating temperature range and 5-95% noncondensing relative humidity specification define the stated environmental operating conditions. Actual output loading should remain within both the individual channel limit and the total module rating.
Frequently Asked Questions
Q: How many output channels does the Allen Bradley 1794-OM8 have?
A: The 1794-OM8 has eight nonisolated AC output channels. Each channel supports up to 500 mA, with a maximum total module current rating of 4.0 A.
Q: Which terminal base units are compatible with the 1794-OM8?
A: The listed compatible terminal bases are 1794-TBNF and 1794-TBN. The terminal base provides the field wiring connection and interface to the FLEX I/O bus.
Q: Can the 1794-OM8 be removed while the system is powered?
A: The supplied product description states that FLEX I/O modules can be inserted or removed under power because the I/O module has no direct field wiring connection. However, confirm the applicable system configuration and installation procedures before performing live replacement.
Q: What is the difference between the 1794-OM8 output rating and its module current rating?
A: The 500 mA rating applies to each individual output, while 4.0 A represents the maximum combined current rating for all eight outputs. Both limits must be observed when configuring connected loads.
