ABB AC 800M Complete Guide

8.2 Backup Battery Management

Except for models such as PM857, PM863, PM865, PM867 that do not have built-in batteries or do not require batteries, all other CPUs have built-in lithium batteries (3.6V, 0.95Ah, 1/2 AA, lithium content 0.3g). The battery is used to maintain the real-time clock and programs in RAM (if there is no Flash storage).

Replacement cycle: Every 3-5 years. When the 'Battery Low' LED flashes, it needs to be replaced within 2 weeks. Steps:

Ensure that the CPU is powered on (otherwise RAM data will be lost).

Open the front panel, remove the old battery, and install a new battery (model ER14250 or equivalent) within 30 seconds.

Reset battery alarm (via Control Builder's' Clear Battery Fault ').

Attention: The transportation of CPUs containing lithium batteries must comply with UN3091 regulations, and single cell batteries with lithium content<1g can be exempted.

Quick Reference Table for Common Fault Codes (Based on Practical Summary)

Possible causes and solutions for the fault phenomenon

The CPU is stuck in the Initiat state, and the application program is missing or the memory verification has failed. Download the program again through Control Builder; Check battery voltage

CEX bus module does not recognize that the module is not securely plugged in or there is a backplane address conflict. Power off and reinsert; Check addresses (1-12) in hardware configuration

Enable termination on TB807 if the communication timeout terminal resistance is not set or the cable is too long (>25m); Using fiber optic extension

Intermittent disconnection and poor grounding of PROFIBUS slave station or incorrect bus bias voltage inspection of shielding layer single point grounding; The measured A/B line to ground voltage should be 2.5~3.5V

Ethernet channel loss, switch aging or IP conflict, replacement of industrial switch; Using Wireshark packet capture analysis

CI873 failed to connect to CompactLogix due to instance ID or connection size mismatch. Modify the data length of the target device in Studio 5000