Next-Generation PT Dual-Bus Voltage Transfer Relay

TonyZhang
Oct 4
2 min read

In dual-bus substations, the PT voltage transfer circuit is fundamental to stable switching for measurement, protection, and monitoring. But integrators face tough realities: high-density panels, limited cabinet space, and short retrofit windows. The question is how to deliver high-quality projects without redesigning drawings while still meeting today’s engineering constraints.

The new RUS11D(S) PT dual-bus voltage transfer relay addresses exactly that. Built on an upgraded industrial housing platform, it retains all terminal definitions and functions, while offering smaller size, more flexible wiring, and faster assembly—turning complex jobs into simple, repeatable installations.

Upgrade 1 — Compact Housing, 64% Rail Savings

Before: 126 × 90 × 66.6 mm (L×W×H)
After: 45 × 88 × 102.1 mm (L×W×H)

Engineering value

DIN-rail length reduced from 126 mm to 45 mm—≈64% saving.
Optimized height/width ratio creates horizontal rail margin, supporting modular series installation and easier wiring zones.
More freedom in dense cabinets and room for future expansion.

Upgrade 2 — Double Terminal Capacity

Before: 2.5 mm² × 1
After: 2.5 mm² × 2

Engineering value

Supports double-wiring, ideal for local convergence of bus voltages, disconnector position signals, and multi-branch connections.
Reduces reliance on intermediate terminals and jumpers.
Boosts installation efficiency and circuit reliability in complex layouts.

Upgrade 3 — Zero-Disturbance Transition

Terminal definitions and functions are fully identical between old and new products.
Design drawings remain unchanged—no re-engineering required.
Retrofit projects: direct swap with existing units, preserving numbering and wire labels.
Less commissioning workload within outage windows, smoother acceptance for design and procurement teams.

The new RUS11D(S) PT dual-bus voltage transfer relay delivers measurable gains: 64% space savings, double wiring capacity, and zero-disturbance replacement. For secondary protection integrators and utility projects, it represents a practical way to ease cabinet constraints and accelerate high-quality delivery.

If your projects face challenges with dense cabinet layouts, retrofit constraints, or wiring complexity, the RUS11D(S) offers a proven upgrade path.