Honeywell 51303968-100 PM/APM CMOS Backup Assembly Board

Configured for preserving volatile system configuration data in Honeywell Process Manager (PM) and Advanced Process Manager (APM) Standard Power Systems, the Honeywell 51303968-100 (51303968-100 CMOS Backup Assembly Board) provides direct physical/electrical execution for memory retention and battery charge monitoring across process control networks.

Hardware Specifications

4-20 mA HART Loop Protocol and Power System Isolation

In Honeywell DCS architectures, the power subsystem maintains clean continuous voltage rails to prevent memory corruption during utility transfer cycles. The Honeywell 51303968-100 incorporates dedicated charging and failure-alarm monitoring circuitry that isolates volatile CMOS storage nodes from main bus power drops. Channel-to-channel isolation across adjacent backplane signal paths ensures that battery charging pulses and diagnostic monitoring signals do not induce high-frequency ripple into neighboring analog input cards running sensitive 4-20 mA HART loop protocol lines.

Frequently Asked Questions

Q: What physical disassembly steps are required to access and replace the board on the chassis backpanel?

A: Technicians must first isolate supply power, then slide out the right-hand power supply module to reach the lower right-hand corner of the power-system backpanel chassis where the dedicated mating connector resides.

Q: How does the onboard battery monitoring circuit alert the control system to backup failure?

A: The board continuously samples battery terminal voltage and charge current. If the battery voltage drops below operational thresholds or the charging current fails, the circuit triggers a dedicated failure contact on the backpanel bus to alert the system alarm manager.

Field Installation Guidelines

Align the card edge with the dedicated connector on the lower right-hand side of the power system backpanel. Seat the assembly straight into the connector pins without rocking to prevent pin bending, then secure all mechanical retention fasteners.

Ensure the system ground braid connects securely to the cabinet chassis earth bus to establish a low-impedance ground path before re-engaging primary AC power feeds. Verify that the onboard 0.5 A time-delay fuse remains intact prior to closing the cabinet. Before performing board insertion or battery replacement, switch off main circuit breakers or confirm that the local area meets non-incendive hazardous location safety standards.