Description
The Eaton Cutler-Hammer 4A55765H11 is a replacement main internal display board assembly designed explicitly for the DIESEL Plus and LMR Plus series of fire pump controllers, with primary application in FD120 Diesel Engine Fire Pump Controllers manufactured after June 2015. The assembly functions as the computational and visual engine behind the controller’s front-door user interface. It drives the 4-line by 40-character backlit LCD display screen, controls the system status/alarm discrete LEDs, and decodes operator selections from the door-mounted membrane keypad layout.
Commercial Availability & Procurement Terms
- Condition: New Original (Factory Sealed Service Stock)
- Warranty: 12-Month Functional Warranty
- Availability: In Stock
- Standard Lead Time: Ships within 1–2 business days via global couriers (DHL, FedEx, UPS)
- Pricing Policy: Indicative pricing only. Final transaction pricing varies with emergency turnaround requirements and production line component availability. Contact our sales department for a formal, time-bound quote.
Technical Specifications
| Parameter | Specification / Value |
| Model / Part Number | 4A55765H11 (Component SKU: E-4A55765H11) |
| Manufacturer | Eaton Corporation / Cutler-Hammer |
| Application Layer | Main Display Logic Board Assembly |
| Specific Model Legacies | Optimized for FD120 Diesel Controllers (Post-June 2015) |
| Incompatible Platforms | Do not deploy on legacy FD100 or FD110 series controllers |
| Integrated Display | 4-Line \times 40-Character alphanumeric backlit LCD |
| Interfacing Devices | Pairs with 99-5835-12 Logic Board and 4A55765H02 Power I/O Board |
| Status LED Drivers | Controls active lines for Engine Run, Remote Start, Deluge, and Interlock |
| Alarm LED Drivers | Maps standard arrays for Battery Fail, Charger Fail, Low Fuel, and Overspeed |
| Operating Temperature | +4 to +50 °C (+39 to +122 °F) |
| Enclosure Footprint | Interior panel door-mount alignment |
Deployment Constraints & Engineering Notes
1. Hard Manufacturing Date Constraints
The 4A55765H11 display board contains specialized internal trace adjustments and updated firmware structures optimized for industrial diesel engines deployed post-June 2015.
Field Warning: Do not attempt to use this board as a direct retrofit for FD120 panels built before June 2015, nor on any standalone FD100 or FD110 platforms. Older configurations utilize legacy voltage scaling loops and differing communications bitrates. Installing this board in an incompatible hardware environment will result in a blank display or immediate communication fault codes on the auxiliary logic module.
2. Electrostatic Discharge Handling and Isolation
The multi-layer PCB features highly exposed surface-mount CMOS microchips that can be easily degraded or destroyed by static discharge.
- Power Down Protocols: Disconnect all AC utility line drops powering the internal battery chargers, and physically disconnect both redundant 12/24 V DC engine starting battery banks before opening the inner cabinet doors.
- Grounding Measures: The technician must wear a calibrated anti-static wrist strap clipped directly to the unpainted steel sub-plate of the enclosure grounding terminal during assembly extraction and insertion.
3. Peripheral Alignment and Cables
The 4A55765H11 contains the micro-components for the processing screen layer, but it does not ship with ancillary replacement parts. When executing a field overhaul following a severe power surge, trace the integrity of the 4A55723H01 data ribbon cable and the front outer graphic sheet (Eaton Membrane Part Number 99-5816-01). Mating a new display card to an physically cracked or moisture-compromised button membrane will prevent menu button registration.
Frequently Asked Questions
Does the 4A55765H11 display board require separate firmware flashing upon installation?
No. The 4A55765H11 is shipped with base display firmware pre-loaded. It automatically reads and mirrors the deep site-specific engine parameter data, historical diagnostic buffers, and pressure switch setpoints directly from the panel’s primary storage block located on the companion 99-5835 series main logic processor board.
What should I inspect if the screen lights up blue or green but shows no character text?
First, power down the enclosure inputs and verify that the multi-pin data ribbon cable is perfectly seated and square within its slot latch. If the ribbon cable is twisted or askew by even a single pin, power paths will latch but digital data streams will fail to execute, causing a blank backlit screen error state.
Can this board display language arrays other than English?
Yes. The firmware integrated onto the 4A55765H11 display board structure is capable of generating multiple operating languages. The user can toggle these translation tables directly through the initial configuration software steps using the front panel keypad options.
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