Mistake 5 - Improper Grounding & Shielding in PAGA Systems

Mistake 5 Improper Grounding & Shielding in PAGA System.

When we first powered up the system, everything looked fine, amplifiers came to life, speakers across zones were active, and audio flowed clearly. But then, during final testing, something wasn’t right.

Here is mistake 5 in our series: 7 mistake we made when deploying a PAGA system – so you don’t have to.

What did we notice?

A low hum.
Occasional buzzing.
Subtle interference in a few zones.

It wasn’t catastrophic, but it was enough to degrade the clarity of voice announcements. In a PAGA (Public Address and General Alarm) system, that’s unacceptable—especially when clarity is critical during emergency situations.

What went wrong?

We had a grounding and shielding strategy documented and approved. But in reality, a few small details were missed during implementation:

Some sections didn’t use shielded cables due to space constraints or design assumptions.
In other areas, shielded cables were grounded at both ends, creating ground loops and inviting noise into the system.

This inconsistency led to minor distortion in select zones, compromising the system’s overall audio intelligibility.

The Impact on System Performance

Even small oversights can affect a well-designed system. In the case of PAGA, poor shielding and grounding introduce noise that interferes with emergency communication clarity—putting personnel safety at risk.

The system wasn’t a failure, but it fell short of the quality standards we strive for.

How did we Fix it?

We learned from the mistake and upgraded our installation protocols:

Shielded twisted-pair cables are now mandatory for all audio paths.
We use single-point grounding only—no exceptions.
Continuity and bonding checks are performed across all racks and JB connections.
Line-level noise testing is added as a QA step before handover.

In critical systems like PAGA, consistency is everything. Every cable, every connection, every ground matters.