Eaton Wheelock INC-PS10 Intelligent Notification Controller: The Addressable NAC Power Supply Explained
The Eaton Wheelock INC-PS10 Intelligent Notification Controller is much more than another fire alarm booster power supply. It combines up to 10 amps of special-application notification power with digital NAC trunks, addressable Sub-NAC modules, branch-level fault isolation, detailed LCD diagnostics, programmable auxiliary power, Class A and Class B flexibility, and sophisticated troubleshooting capabilities.
In a traditional addressable fire alarm system, much of the intelligence ends when the notification appliance circuit leaves the panel. Smoke detectors, monitor modules, control modules and other initiating devices may be individually addressable, while the horns, strobes and horn/strobes remain connected to comparatively conventional supervised NAC wiring.
The Eaton Intelligent Notification Controller changes that relationship.
Instead of simply adding more 24-volt notification power, the INC-PS10 can extend intelligence farther into the notification distribution system through Eaton's addressable Sub-NAC architecture. The result is a system capable of identifying, reporting and containing certain notification circuit faults much closer to where they actually occur.
What Is the Eaton INC-PS10 Intelligent Notification Controller?
The Eaton INC-PS10 Intelligent Notification Controller is a smart, modular life-safety power and notification controller designed to provide notification appliance power while adding enhanced supervision, diagnostics and fault resiliency.
The controller is designed for applications including fire alarm notification, mass notification, carbon monoxide signaling, access control and certain building-control functions when installed in accordance with its listings and manufacturer requirements.
The INC-PS10 provides four primary output circuits. Each output can be configured for conventional notification appliance operation, addressable NAC operation using Eaton Sub-NAC modules, or auxiliary power applications.
Each output can provide up to 3 amps, subject to the overall controller limitations. Eaton publishes a system rating of 10 amps for Wheelock special-application loads and 7 amps regulated.
Eaton INC-PS10 Specifications at a Glance
| Specification | INC-PS10 Rating |
|---|---|
| Total special-application power | 10 A |
| Total regulated power | 7 A |
| Main output circuits | 4 |
| Maximum per output | 3 A |
| Auxiliary power | 3 A per output / 6 A total |
| Activation inputs | 4 |
| Programmable relays | 3 |
| Dedicated trouble relay | 1 |
| Digital NAC trunks | Up to 4 |
| Sub-NACs per digital NAC trunk | Up to 8 |
| Maximum Sub-NACs per INC | 32 |
| Maximum Class B Sub-NAC branches | 64 |
| Internal battery accommodation | Two 12 V sealed lead-acid batteries, up to 18 Ah each |
| Maximum charging capability | 55 Ah with external battery cabinet |
| AC input | 120 VAC |
| Published AC operating range | 102-132 VAC |
| Published maximum AC current | 4.5 A in Eaton specification table |
| NAC output voltage range | 19.95-26.6 VDC |
| AUX output voltage range | 19.95-26.4 VDC |
| Operating temperature | 32°F-120°F (0°C-49°C) |
| Humidity | 93% RH non-condensing |
| Environment | Indoor, dry |
| Unit weight | 17.2 lb |
| Cabinet dimensions | 19.3"H × 19.1"W × 3.5"D |
Inside the Eaton INC-PS10 Cabinet
Opening the enclosure makes it clear that the INC is considerably more sophisticated than a conventional remote NAC booster.
The cabinet contains the primary controller and power electronics, CPU/LCD assembly, field terminals, battery charging circuitry, activation inputs, relay outputs, configurable NAC/AUX outputs and internal space for batteries and optional Sub-NAC modules.
Up to two 18 Ah batteries can be physically installed inside the cabinet. Eaton also allows up to two Sub-NAC modules to be mounted internally, potentially eliminating the need for separate external electrical boxes for those modules.
The Eaton cabinet illustration also identifies the separation between the non-power-limited AC and battery area and the power-limited field wiring area. Required conductor separation and wiring practices must be maintained in accordance with the manufacturer's installation instructions and applicable electrical and fire alarm requirements.
Four Outputs: Conventional NAC, Addressable NAC or Auxiliary Power
The four INC output circuits are not restricted to one function. Depending on the approved system design, each output can be configured as a conventional notification appliance circuit, an addressable digital NAC trunk, or an auxiliary-power circuit.
The conventional NAC output configurations identified by Eaton include:
- Four Class B circuits
- Two Class A circuits
- One Class A circuit plus two Class B circuits
Each output is rated for up to 3 amps, while total system loading must remain within the applicable 10 A special-application or 7 A regulated rating.
What Is a Digital NAC Trunk?
The digital NAC trunk is the heart of the INC's addressable notification architecture.
Rather than treating the notification circuit only as a pair of supervised conductors supplying power to horns and strobes, the INC can use the NAC trunk to communicate digitally with addressable Eaton Sub-NAC modules distributed throughout the notification circuit.
A simple way to visualize the architecture is:
Compatible conventional notification appliances and addressable Sub-NAC modules can coexist on the same supported wiring architecture.
That creates a hybrid system in which the notification appliances themselves can remain conventional while the distribution infrastructure becomes intelligent.
What Is an Eaton Sub-NAC?
The Eaton Sub-NAC is an addressable notification appliance circuit module that communicates with the INC and creates individually supervised notification branches.
Each Sub-NAC contains its own microprocessor. Rather than acting as a passive splice point, the module independently supervises its branch circuits and communicates digital status information back to the INC.
A single Sub-NAC can be configured as:
- Two Class B branches, each supporting up to 1 amp, or
- One Class A branch supporting up to 1 amp.
When configured as two Class B branches, the module can therefore support up to 2 amps total, subject to all system power, conductor and voltage-drop limitations.
The Sub-NAC supervises its branch circuits for opens, shorts and overcurrent conditions while active. It also communicates its address and branch status back to the INC.
Eaton specifies communication between the controller and Sub-NAC as RS-485 half-duplex.
How Is a Sub-NAC Addressed?
Each Sub-NAC includes an eight-position rotary address selector on the module. Up to eight Sub-NAC addresses are available on each digital NAC trunk.
A status LED remains visible with the front cover installed and provides local indication of normal, fault and active conditions.
The module can be installed in a standard 4-inch electrical backbox or in one of the supported mounting positions inside the INC enclosure.
Does the INC Make Every Horn and Strobe Addressable?
No. This distinction is essential to understanding the system.
The Sub-NAC modules are addressable. The compatible horns, strobes and horn/strobes connected to the digital trunk and downstream branch circuits remain conventional notification appliances.
The intelligence is added to the notification distribution architecture instead of requiring an individual address at every notification appliance.
How Do 32 Sub-NACs Become 64 Notification Branches?
The maximum addressable architecture is easy to calculate:
4 Digital NAC Trunks × 8 Sub-NACs per Trunk = 32 Addressable Sub-NAC Modules
32 Sub-NACs × 2 Class B Branches = Up to 64 Class B Branch NACs
This does not mean the controller produces 64 amps of notification power. Every circuit remains subject to the controller's available power, individual 3 A trunk ratings, Sub-NAC branch limits, conductor limitations, appliance compatibility and voltage-drop requirements.
The advantage is not unlimited power. It is far greater distribution flexibility and circuit segmentation.
Branch-Level Fault Isolation: Where the INC Really Gets Interesting
One of the defining features of the Sub-NAC architecture is the ability to keep a localized wiring problem from unnecessarily affecting a much larger notification circuit.
If a Sub-NAC detects a short on one branch, its microprocessor can isolate the affected branch. If an active branch exceeds its supported current level, the module can current-limit and open that branch.
The goal is straightforward: contain the failure.
A problem on one branch should not unnecessarily disable the entire NAC trunk and every notification appliance connected elsewhere on it.
What Fault Information Can the INC Provide?
Depending on the fault and configuration, the INC can identify information including:
- NAC trunk
- Sub-NAC address
- Fault type
- Individual branch circuit
That is dramatically more information than the generic "NAC Trouble" indication associated with many traditional booster architectures.
Ground Fault Detection Down to the Sub-NAC Level
Ground faults can be some of the most time-consuming fire alarm problems to locate.
A pinched conductor, damaged insulation, moisture in an exterior appliance, wiring contacting a metal enclosure or an errant fastener can place one side of the fire alarm circuit onto ground somewhere across a large building.
The INC includes a dedicated ground-fault diagnostic mode capable of identifying the fault down to the affected Sub-NAC address.
That wording is important. The INC does not claim to identify the exact damaged conductor or appliance. Instead, it can dramatically reduce the physical area a technician must investigate.
The Sub-NAC Location Lookup Table
Eaton's documentation calls for the installer to complete a site-specific lookup table linking each Sub-NAC address to its physical location.
For example:
This lookup information can then be maintained at the INC so future maintenance personnel can translate an electronic Sub-NAC ID into a physical location in the building.
Yes, the Sub-NAC Architecture Allows Supervised T-Taps
T-tapping has traditionally been a dangerous phrase in fire alarm work because many conventional supervised circuits depend on a specific wiring topology.
The INC/Sub-NAC architecture is different.
Eaton specifically designed the Sub-NAC to create fully supervised branch circuits from the primary NAC trunk. The Sub-NAC's independent microprocessor supervises those branches and reports their status digitally back to the controller.
This can reduce the need for individual home-run circuits, potentially reducing conductor and conduit requirements on appropriate projects.
Class A Trunks, Class B Branches and Flexible Circuit Architecture
The digital NAC trunk itself can be configured using supported Class A or Class B architecture. The downstream Sub-NAC branches can independently be configured as two Class B circuits or one Class A circuit.
This creates several useful design combinations.
For example, a designer can use a Class A digital NAC trunk feeding multiple Class B Sub-NAC branches. Eaton specifically describes this as a cost-effective way to add another layer of resiliency to the distribution system.
INC-PS10
|
| DIGITAL NAC TRUNK OUT
|
+---- SUB-NAC 1
| +---- Class B Branch 1
| +---- Class B Branch 2
|
+---- SUB-NAC 2
| +---- Class B Branch 1
| +---- Class B Branch 2
|
+---- SUB-NAC 3
+---- Class B Branch 1
+---- Class B Branch 2
<------ CLASS A TRUNK RETURN ------
The actual circuit classification must always match the approved design, equipment listing, applicable codes, pathway requirements and manufacturer instructions.
Why Sub-NAC Branching Can Improve Voltage Drop
Voltage drop is one of the fundamental limitations of large fire alarm notification circuits.
Every foot of conductor adds resistance. Higher notification load increases voltage drop. Eventually, the voltage available at the farthest appliance becomes the limiting design factor.
Traditional solutions include increasing conductor size, shortening circuits, adding remote power supplies or adding more home runs.
The INC architecture provides another option.
The primary digital NAC trunk distributes power through the building while Sub-NACs create smaller downstream notification branches. Because branch current can be significantly lower than the current carried on the primary trunk, voltage drop on those individual branches can be reduced.
This becomes especially useful with modern lower-current LED notification appliances.
For additional fire alarm design information, visit Fire Alarms Online.
Four Programmable Activation Inputs
The INC provides four independent activation inputs.
These can accept supported reverse-polarity fire alarm NAC activation or dry-contact activation. Dry-contact inputs may be configured for normally open or normally closed operation as supported by the controller.
The published NAC-mode input range is 8 to 33 VDC or FWR. Eaton lists approximately 3 mA input current at 12 VDC and 5 mA at 24 VDC.
Input/output mapping is flexible. A single activation input can control multiple outputs or relays, and multiple inputs can control the same output.
This gives the INC the ability to interface with many compatible fire alarm control units instead of limiting it to one proprietary FACP family.
Four Relays: Three Programmable and One Dedicated Trouble Relay
The INC incorporates four relay outputs:
- Three programmable relays
- One dedicated general INC trouble relay
The programmable relays can follow supported input conditions or signal specific system conditions. Eaton's engineering documentation identifies examples including specific fault reporting, door-holder release and fan shutdown.
The published relay contact rating is 30 V, 1 A at 0.6 power factor.
Any control application must remain within the controller listing, relay ratings, sequence of operations and applicable code requirements.
Up to 6 Amps of Programmable Auxiliary Power
The INC can do considerably more than operate horns and strobes.
Outputs configured for auxiliary power can provide up to 3 amps per output and up to 6 amps total auxiliary power, subject to the controller's overall ratings and application requirements.
Eaton identifies supported or listed applications including:
- Electronic lock power and control
- Fire-door release and control
- Fan control
- Damper control
- Power for compatible four-wire detectors
- Mass-notification textual signs
Programmable Battery Standby by Auxiliary Circuit
One particularly unusual capability is the ability to assign different secondary-power durations to individual auxiliary circuits.
Eaton identifies available selections including:
- No battery backup
- 30 minutes
- 2 hours
- 4 hours
- Continuous battery backup
This allows secondary-power allocation to more closely match the needs of the connected function.
It does not eliminate the requirement for battery calculations. The designer must still determine the applicable standby and alarm duration required by the connected equipment, listing, code and jurisdiction.
The INC LCD Is a Real Diagnostic Interface
The blue LCD on the front of the INC is much more than a decorative status display.
It provides menu-driven access to configuration, system status, diagnostics, testing, maintenance information and event history.
Power-status information can include:
- Real-time AC voltage
- Real-time battery voltage
- Real-time load current on each NAC output
- Input conditions
- Output conditions
- Relay conditions
- Specific fault information
This makes the INC much more technician-friendly than power supplies that communicate nearly everything through a small collection of LEDs.
Independent Self-Test Without Activating the Fire Alarm Control Panel
The INC includes self-test capabilities that can be initiated locally without requiring the main fire alarm control panel to activate the controller.
Depending on the selected test function, technicians can operate outputs, toggle relays, test display functions and initiate the detailed ground-fault diagnostic routine.
This can make commissioning and service substantially more efficient, although testing must still be performed in accordance with manufacturer procedures and facility notification requirements.
USB Configuration, History and Screen Capture
The INC incorporates USB functionality for considerably more than simple program transfer.
Eaton identifies USB-related functions including:
- Configuration upload and download
- Program archiving
- Configuration duplication
- Non-volatile event-history storage
- Time- and date-stamped history
- Bitmap (.BMP) screen captures for troubleshooting
The number of externally stored history events is effectively limited by the available USB storage capacity.
The ability to capture the actual INC screen can be particularly useful when documenting intermittent faults or communicating field conditions to technical support.
Temporal 3 Fire and Temporal 4 CO Signaling
The INC supports conventional fire and carbon monoxide signaling functions and has additional capabilities when used with compatible Wheelock Eluxa notification appliances.
In addition to conventional Temporal 3 and Temporal 4 patterns, supported configurations can provide combined T3 fire / T4 CO signaling using compatible Eluxa appliances on the same pair of conductors.
This allows compatible devices to produce different audible patterns depending on whether the system is responding to a fire or carbon monoxide event.
Synchronization and Horn Silence
The controller's published listings include synchronization of compatible Wheelock horns and strobes and supported two-wire horn/strobe operation where the audible signal can be silenced while visual notification continues.
Wheelock Compatibility Makes the INC Especially Interesting for Retrofit Projects
One of the INC system's strongest advantages is that intelligent notification distribution does not necessarily require replacement of every existing compatible Wheelock notification appliance.
Eaton specifically identifies compatibility with supported families including:
- Wheelock RSS xenon notification appliances
- Wheelock Exceder LED3
- Wheelock Eluxa
Supported system configurations can combine compatible xenon appliances, LED notification appliances and addressable Sub-NAC modules on the applicable wiring architecture.
This can make the INC especially attractive for phased renovations, additions and retrofit projects where an existing installed base of compatible Wheelock notification appliances remains serviceable.
For additional sleeping-area notification information, see the Fire Alarms Online 520 Hz low-frequency notification guide.
Battery and Secondary Power Capabilities
The INC uses two 12 V sealed lead-acid batteries to provide secondary power.
The enclosure can accommodate up to two 18 Ah batteries internally. For larger secondary-power requirements, Eaton specifies charger capability up to 55 Ah when an appropriate external battery cabinet is used.
Actual battery capacity must be calculated using the connected standby load, alarm load, auxiliary load, required standby duration, alarm duration and all applicable design factors.
Eaton Sub-NAC Technical Specifications
| Sub-NAC Specification | Manufacturer Rating |
|---|---|
| Branch configuration | Two Class B or one Class A |
| Class B capacity | 1 A per branch, 2 A total |
| Class A capacity | 1 A |
| Rated input voltage | 18.5-24 VDC |
| Minimum voltage at last branch appliance | 16 VDC |
| Standby current | 10 mA |
| Alarm current | 35 mA |
| NAC input conductor range | 12-18 AWG |
| NAC output conductor range | 14-18 AWG |
| Communications | RS-485 half-duplex |
| Maximum modules per digital NAC | 8 |
| Maximum modules per INC | 32 |
| Address selection | Eight-position rotary switch |
| Local indication | Normal, fault and active LED |
| Dimensions | 4.68 × 4.61 × 1.10 in |
| Weight | 9 oz / 255 g |
| Operating temperature | 32°F-120°F / 0°C-49°C |
| Humidity | 93% RH non-condensing |
| Environment | Indoor dry |
| Standard mounting | 4-inch square × 2-1/8-inch deep electrical box |
| INC internal mounting | Up to 2 modules |
Eaton INC-PS10 vs. a Conventional Fire Alarm NAC Booster
| Feature | Typical Conventional NAC Booster | Eaton INC-PS10 / Sub-NAC Architecture |
|---|---|---|
| Primary purpose | Add notification power | Add power plus intelligent notification distribution |
| Addressable field distribution | Typically no | Yes, using addressable Sub-NAC modules |
| Branch supervision | Generally circuit-level | Independent Sub-NAC branch supervision |
| Short-circuit isolation | Entire NAC may be affected | Affected Sub-NAC branch can be isolated |
| Active overcurrent protection | Varies by product | Branch current limiting and isolation |
| Ground-fault localization | Often requires manual circuit division | Can identify the affected Sub-NAC address |
| Supervised branching | Normally restricted by circuit topology | Supported through the listed Sub-NAC architecture |
| Local diagnostics | Often LEDs or basic display information | Detailed LCD menus and fault information |
| Real-time output current | Varies | Available through power-status screens |
| Independent local testing | Varies by manufacturer | Outputs, relays, display and ground-fault testing |
| USB configuration/history | Varies | Supported |
| Auxiliary power | Product dependent | Up to 6 A total |
| Maximum intelligent branch modules | Not applicable | 32 Sub-NAC modules |
| Maximum Class B branches | Product dependent | Up to 64 |
A conventional booster remains entirely appropriate for many fire alarm systems. The advantage of the INC becomes increasingly compelling as circuit distance, retrofit constraints, troubleshooting requirements, fault resiliency and distribution complexity increase.
What Fire Alarm Designers Need to Consider
Intelligent notification architecture does not eliminate traditional fire alarm engineering. It gives the designer additional options for distributing power and supervising notification circuits.
A complete INC design should evaluate, at minimum:
- Notification appliance compatibility
- Special-application versus regulated loading
- Total controller loading
- Individual 3 A output limitations
- Sub-NAC branch loading
- Voltage drop
- Wire gauge and conductor resistance
- Minimum appliance operating voltage
- Class A versus Class B topology
- Required pathway survivability
- Input/output mapping
- Audible and visible notification requirements
- Synchronization requirements
- Battery standby and alarm calculations
- Auxiliary-power requirements
- Applicable NFPA 72 requirements
- Applicable NFPA 70 requirements
- Locally adopted building and fire codes
- Manufacturer installation instructions
- Equipment listing limitations
- Authority Having Jurisdiction requirements
For sleeping-area notification design, visit the 520 Hz low-frequency notification guide.
For occupancy-based requirements, visit the Fire Alarm Requirements by Occupancy Group guide.
Why the INC Architecture Is Especially Useful to Service Technicians
The biggest advantage for a service technician may not be the controller's 10-amp special-application capacity at all.
It is the amount of information available during a fault.
Instead of beginning every service call by manually dividing a long NAC into progressively smaller sections, the technician may already know the:
- Affected NAC trunk
- Sub-NAC address
- Affected branch
- General fault type
- Mapped physical location
That can turn a building-wide troubleshooting exercise into a much more targeted investigation.
Troubleshooting Example
Instead of arriving to a generic:
NAC 2 TROUBLE
the INC/Sub-NAC architecture may allow the technician to narrow the problem conceptually to:
That is the practical value of moving intelligence farther downstream into the notification system.
Real-World Bench Testing of the INC-PS10
The photographs throughout this article show an actual INC-PS10 configured as a training and demonstration system.
External switches were connected to the INC activation inputs so individual input conditions could be created manually while notification appliances and Sub-NAC branches were connected to the output circuits.
A controlled training setup can be used to study:
- Normal controller status
- Input activation
- Output mapping
- Relay operation
- Open branch detection
- Short-circuit isolation
- Overcurrent response
- Ground-fault diagnostics
- Notification appliance operation
- LCD status changes
INC-PS10 Listings and Applications
Eaton identifies the INC controller with published compliance and listing references including:
- UL 864, 10th Edition
- UL 2572 for mass notification
- UL 294 for access-control applications
- ULC-S527 fire alarm applications
- ULC-S576 mass-notification applications
- ULC-S318 access-control/burglar applications
- Additional ULC references for applicable INC accessories
- California State Fire Marshal listing
The dedicated Sub-NAC documentation separately identifies UL 864, UL 2572, ULC-S527-19 and ULC-S576 listings for the Sub-NAC module.
Eaton INC Ordering and Replacement Part Information
| Model | Description |
|---|---|
| INC-PS10 | 10 A Intelligent Notification Controller, red enclosure, 120 V |
| INC-CAB1-DOOR | Replacement INC cabinet door |
| INC-PS10-ELEC | Replacement INC motherboard and power supply assembly |
| INC-CPU | Replacement base computer with LCD display |
| INC-USB | INC USB accessory |
| SUB-NAC | Addressable notification branch module with white cover |
| EOLR-1K | 1 kΩ end-of-line resistor package |
| EOLR-10K | 10 kΩ end-of-line resistor package |
| INC-DSM-PL | Internal Dual Sync Module mounting plate |
Always verify current part numbers, availability, equipment revisions and accessory compatibility directly with Eaton or an authorized distributor before specifying replacement equipment.
Common Misconceptions About the Eaton INC
“It is just a 10-amp booster.”
No. While the INC can perform conventional notification power functions, its digital NAC architecture, Sub-NAC modules, diagnostics, auxiliary power and programmable control capabilities go far beyond a traditional booster.
“Every horn and strobe becomes addressable.”
No. The Sub-NAC module is addressable. Compatible downstream notification appliances remain conventional.
“You can T-tap any NAC because the INC allows T-taps.”
No. Supervised branching is specifically associated with the listed INC/Sub-NAC architecture.
“A Sub-NAC ground fault tells you exactly which wire is damaged.”
No. The diagnostic feature can identify the affected Sub-NAC address, greatly reducing the troubleshooting area, but the technician must still locate the physical fault.
“10 amps means 10 amps regulated.”
No. Eaton specifies 10 A special application for compatible Wheelock loads and 7 A regulated.
“Addressable NACs eliminate voltage-drop calculations.”
No. The distributed architecture can significantly improve voltage-drop performance, but normal engineering calculations remain required.
The Bottom Line
The Eaton Wheelock INC-PS10 represents a very different approach to fire alarm notification appliance circuit distribution.
Its most important feature is not simply that it can deliver 10 amps of special-application notification power.
The real innovation is what happens after the power leaves the cabinet.
Through four configurable outputs, digital NAC trunks and as many as 32 addressable Sub-NAC modules, the INC can distribute notification power while adding branch supervision, short-circuit isolation, active current limiting, ground-fault localization and substantially more detailed troubleshooting information.
A system using the maximum Class B Sub-NAC architecture can create as many as 64 supervised notification branches while compatible conventional Wheelock notification appliances remain downstream.
For designers, that creates a much more flexible distribution architecture.
For installers, it can reduce home-run wiring and conduit in appropriate applications.
For building owners, it can improve system fault resiliency and maintainability.
And for the technician trying to find a wiring fault in a large building, knowing which Sub-NAC and branch to investigate is considerably better than staring at a generic NAC trouble indication and wondering where to begin.
Frequently Asked Questions About the Eaton INC-PS10
Is the Eaton INC-PS10 an addressable power supply?
The INC-PS10 is an intelligent notification controller capable of conventional NAC operation as well as digital addressable NAC trunk operation using Eaton Sub-NAC modules. The Sub-NAC distribution modules are addressable; compatible notification appliances downstream remain conventional.
How many amps does the Eaton INC-PS10 provide?
Eaton publishes a 10 A total special-application rating for compatible Wheelock loads and a 7 A regulated rating. Each of the four main output circuits is rated for up to 3 A, subject to the overall controller limit.
How many Sub-NACs can one INC support?
Each of the four digital NAC trunks can support up to eight Sub-NAC modules, providing a maximum of 32 Sub-NAC modules per INC.
How many notification branches can the INC support?
Each Sub-NAC can provide two Class B branches. With 32 Sub-NAC modules, the maximum architecture can therefore provide up to 64 Class B branch NACs, subject to all controller loading and design limitations.
How much current can an Eaton Sub-NAC provide?
A Sub-NAC can provide up to 1 A per Class B branch, for up to 2 A total when configured with two Class B branches. When configured as one Class A circuit, the maximum is 1 A.
Can the Eaton Sub-NAC isolate a short circuit?
Yes. Eaton designed the Sub-NAC to isolate a branch containing a short and to protect unaffected portions of the digital NAC trunk.
Can the INC identify a ground fault?
Yes. Its special ground-fault diagnostic mode can identify a ground fault down to the affected Sub-NAC address. It does not identify the exact damaged conductor.
Can Sub-NAC circuits be T-tapped?
The Sub-NAC architecture specifically supports supervised branching and T-taps because each Sub-NAC independently supervises its branches. This should not be confused with indiscriminately T-tapping conventional NAC wiring.
Can a Sub-NAC be wired Class A?
Yes. A Sub-NAC can be configured as one Class A branch or two Class B branches.
Can the digital NAC trunk itself be Class A?
Yes. Eaton documents Class A digital NAC trunk architecture, including configurations where a Class A trunk supplies Sub-NAC modules serving Class B branches.
Does the INC support auxiliary power?
Yes. The INC supports up to 3 A auxiliary power per output and up to 6 A auxiliary power total, subject to applicable controller limitations.
Can auxiliary circuits have different battery standby periods?
Yes. Eaton identifies programmable selections including no backup, 30 minutes, 2 hours, 4 hours and continuous battery backup.
How many batteries fit inside the INC cabinet?
The cabinet can accommodate two 12 V sealed lead-acid batteries up to 18 Ah each. The charging system supports up to 55 Ah with an appropriate external battery cabinet.
Can Sub-NAC modules be installed inside the controller?
Yes. Up to two Sub-NAC modules can be physically mounted within the INC enclosure.
What communication method does the Sub-NAC use?
Eaton specifies RS-485 half-duplex digital communication between the INC controller and its addressable Sub-NAC modules.
Can the INC test notification outputs without activating the main fire alarm panel?
Yes. The INC includes local self-test capabilities for outputs, relays, display functions and ground-fault diagnostics.
Does the INC work with older Wheelock notification appliances?
Eaton specifically identifies compatibility with supported Wheelock RSS xenon, Exceder LED3 and Eluxa product families. Exact model compatibility should always be confirmed using Eaton's current compatibility documentation.
Manufacturer References and Additional Resources
This article was developed using Eaton's published INC-PS10 technical data, dedicated Sub-NAC technical data, INC system brochure and hands-on photographs of an INC training system. Because equipment specifications and compatibility information can change, always consult the current manufacturer documentation before specifying, installing or servicing the equipment.
- Eaton Intelligent Notification Controller Official Product Page
- Eaton INC-PS10 Technical Data Sheet — TD450164EN
- Eaton Sub-NAC Technical Data Sheet — TD450165EN
- Eaton INC Systems Brochure — BR450044EN
- Fire Alarms Online
- Fire Alarm Requirements by Occupancy Group
- 520 Hz Low-Frequency Fire Alarm Notification Guide
