Understanding the AL50 Fault Alarm

When a client recently reached out concerning the AL50 fault alarm on their NC servo feeder, it sparked an investigation into the root cause of this issue. The AL50 alarm typically signals an overload condition within the system. In this comprehensive guide, we will delve into the various factors contributing to this alarm, providing valuable insights for effective maintenance and troubleshooting.

Exploring Electrical Factors

1. Reinstallation Impact: A Common Culprit

One prevalent issue leading to the AL50 alarm is improper collisions during the reinstallation of the NC servo feeder. This can impact the servo motor or drive, resulting in a malfunction. Additionally, vibrations within the NC servo feeder’s electrical cabinet may cause internal loosening of the servo motor.

Diagnosing the Problem

To identify this issue, a recommended approach involves a power interruption followed by a re-energization. Manually controlling the feeder for inching forward and backward without triggering an alarm can potentially eliminate this possibility. If such a situation arises, it may be necessary to replace the servo system, albeit a complex process. It’s essential to note that the probability of this fault occurrence is minimal and infrequent, making it of lesser significance.

Unveiling Mechanical Aspects

1. Bearing Jamming: A Potential Issue

Another common source of the AL50 alarm is the jamming of the NC servo feeder’s rolling bearings. To assess this, a power outage in the servo is required, followed by manually rotating the feeding drum under no-load conditions. If noticeable sticking or a lack of smooth movement is observed, it indicates a bearing malfunction.

Testing Procedures

During testing, ensuring cleanliness between two drums and two gears is imperative. While the incidence of this fault is relatively low and seldom encountered, addressing it involves bearing replacement.

2. Mold Replacement Discrepancies

Post mold replacement, discrepancies in the lower mold height compared to the previous mold or inconsistent locating pin lengths may lead to a delay in relaxation time, triggering an alarm due to the stretching of the locating pin material.

Detection and Resolution

Detecting this issue involves manually controlling the press to slowly descend, closely observing the drum’s relaxation time, and repeatedly testing to unveil the problem. A resolution includes adjusting the relaxation time, aligning the NC servo feeder’s feeding height with the mold, or lowering it by approximately 3mm.

3. Material Thickness and Limiting Blocks

Changing materials to thicker ones and subsequently adding a limiting block in the front may induce alarm occurrences, although the likelihood is minimal and seldom realized.

Client Detection for Identification

In such cases, client detection suffices for identification, allowing for proactive measures to address any arising issues.


Understanding the intricacies of the AL50 fault alarm on an NC servo feeder is crucial for efficient troubleshooting and maintenance. By exploring both electrical and mechanical aspects, this guide equips you with the knowledge needed to identify, diagnose, and resolve the underlying causes, ensuring optimal performance and longevity of your equipment.

nc servo feeder
nc servo feeder