Why Secondary Protection for Elevator Compensation Chains Is Essential?

When we think about elevator safety, we usually focus on the ropes that lift the car or the brakes that stop it. But there’s another crucial part hiding in the pit: the compensation chain. This chain balances the weight of the power and control cables as the elevator moves. Over time, chains can wear, links can break, or guides can slip, leading to sudden slack or even derailment. That’s why secondary protection—a backup safety system for the chain—is so important. In this article, we’ll explain why adding this extra layer of protection matters for your elevators and how it keeps everyone safe.

What Does a Compensation Chain Do?

First, let’s quickly review why elevators need a compensation chain:

Load Balancing
As the elevator moves, power and signal cables on one side lengthen or shorten. The compensation chain on the opposite side balances that change, preventing uneven loads on the drive system.
Smooth Operation
Proper tension in the chain ensures a comfortable, jerk-free ride by absorbing minor cable weight shifts.
System Longevity
By sharing cable weight smoothly, chains reduce stress on the traction machine, pulleys, and guide rails—extending their service life.

Given their constant bending and exposure to pit conditions, compensation chains can wear, corrode, or even fracture a link over time.

Why Secondary Protection Matters?

When a primary chain link fails or a guide wheel slips, the chain can derail, creating dangerous slack or snagging cables. Effective secondary protection steps are needed to prevent a minor chain fault from turning into a major safety incident.

Preventing Chain Derailment

A single broken link can allow the chain to jump off its guide wheel. Without backup, that slack chain can:

Snag Control Cables
Tangled cables disrupt signals and power to the car, risking a blackout scenario.
Jerk the Cabin
Sudden loss of tension results in jolts that can startle passengers and damage the drive system.
Trigger Emergency Stops
Many elevator systems detect chain derailment and shut down immediately, stranding occupants.

Secondary protection—whether a backup loop, locking rings, or enclosed guides—catches the chain before it can derail, maintaining continuous tension and balance.

Maintaining Load Balance

Compensation chains share dynamic load changes. If the primary chain loses tension:

Counterweight Shifts
The counterweight can drop or rise unpredictably, unbalancing the system.
Governor and Brake Stress
Sudden load shifts increase demand on overspeed governors and safety brakes, risking delayed engagement.

With secondary protection in place, the backup mechanism immediately picks up load, keeping car and counterweight in harmony until trained personnel can address the issue.

Protecting Cables and Components

A derailed chain can run against pit walls or snag on machinery, leading to:

Cable Jacket Damage
Exposed conductors risk shorts or signal loss.
Pulley and Sheave Wear
Lateral forces on pulleys accelerate groove wear, causing future slippage.
Pit Equipment Strain
Entangled chains can damage sensors, wiring trays, and pit ladders.

Secondary measures act as a safety net—preventing chains from escaping their intended path and damaging sensitive components.

Detailed Look at Secondary Protection Methods

There are three primary methods to back up the compensation chain:

Backup Chain Loop

A second chain runs parallel to the main chain, held slightly slack. If the primary chain fails, the backup loop immediately engages over the guide wheel, preserving chain tension.

Advantages: Easy to retrofit; minimal additional hardware.
Considerations: Slack must be carefully set to avoid normal engagement, yet fast enough to catch a real failure.

Locking Rings on Each Link

Small metal rings clip around individual chain links. When a link fractures, the ring catches on the chain guide channel, stopping the chain from jumping off its track.

Advantages: Compact; works well in confined pits.
Considerations: Rings must glide smoothly over guides and must be inspected regularly for wear.

Enclosed Guide Channels

A rigid metal or polymer channel fully encloses the chain’s travel path. Even if a link breaks, the chain cannot move laterally out of the channel.

Advantages: Maximum containment; no risk of derailment.
Considerations: Requires precise installation and alignment; may be harder to retrofit in existing pits.

Implementing Effective Secondary Protection

To maximize chain safety, we recommend the following best practices:

Proper Sizing and Installation

Alignment: Ensure backup loops, rings, or channels align precisely with chain guides and sheaves.
Tension Setting: Backup chain slack must be correct—too tight causes false engagement; too loose delays protection.
Material Selection: Use corrosion-resistant hardware (stainless steel or treated alloy) to withstand pit moisture.

Routine Inspection and Testing

Monthly Visual Checks: Look for worn backup rings, frayed secondary loops, or debris in channels.
Semiannual Functional Tests: In a controlled environment, simulate a primary chain failure to confirm backup engagement.
Record Keeping: Document installation details, inspection findings, and test results to spot wear trends early.

Maintenance Tips

Clean guide paths with low-pressure air or vacuum—avoid high-pressure sprays that force debris deeper.
Lubricate chain guides and backup components per manufacturer guidelines, ensuring smooth operation.
Replace any secondary element showing wear or deformation—never wait for a failure.

Conclusion

Secondary protection for elevator compensation chains is more than a recommendation—it’s essential for safety, reliability, and regulatory compliance. By adding a backup loop, locking rings, or enclosed guide, we:

Prevent chain derailment
Maintain load balance
Protect cables and pit equipment
Avoid costly emergency shutdowns

As a professional supplier of elevator accessories, we encourage you to look at your compensation chain systems today. Contact POTENSI for high-quality secondary protection components and professional guidance. Together, we’ll keep your elevators running safely, smoothly, and confidently—ride after ride.