Commercial heat pumps

Scroll compressors can draw starting currents up to eight times their nominal current. While this may not be an issue for small, fractional kW/HP compressors, such high inrush currents can cause voltage dips on the grid and interfere with nearby sensitive equipment.

The RSBD and RSBT soft starters are specifically designed for scroll compressors. Featuring a patented self-learning algorithm, they automatically optimize internal parameters to significantly reduce starting current—while maintaining a typical startup time of around 600 ms.

This performance is achieved without requiring any user adjustments, making these soft starters an ideal solution for OEM applications.

Our DIN-rail mount meters include models for both current transformer (CT) connection and direct connection. They combine compact housing with a comprehensive and user-friendly display, delivering accurate and accessible energy data in a space-saving format.

In HVAC systems, the compressor—whether centrifugal, scroll, or screw—is typically driven by an asynchronous motor.
Incorrect phase sequence or phase loss can quickly cause compressor failure due to wrong rotation direction or overheating, leading to extended and costly downtime.
A recommended practice to prevent such critical faults is to install a phase sequence and phase loss relay that can shut down the equipment when necessary.
Our DPA51 monitoring relay is widely used with 3-phase heat pumps. Its compact size, self-powered design, and wide operating voltage range make it easy to install in any electrical panel.

Heat pumps must achieve higher seasonal efficiency ratings to meet market requirements. To maintain high efficiency even during partial load operation, a new generation of compressors capable of operating at variable speeds is required. As a result, permanent magnet (PMAC) and brushless DC (BLDC) compressors are now widely adopted in modern heat pumps.
The RVPM is our variable frequency drive (VFD) designed to operate with both single-phase and three-phase input. It supports PM, BLDC, and induction motor compressors, offering maximum flexibility for a wide range of applications.
For induction compressors up to 0.75 kW (1 HP), the RVBS is an open-board VFD with a compact footprint, ideal for integration into space-constrained electrical enclosures.

The speed of AC condenser fans in rooftop units (RTUs) and chillers can be controlled using phase angle control. By adjusting the output voltage proportionally to an analog input signal, solid-state proportional controllers such as the RGC1P and RGC3P series can regulate the speed of low-starting-torque, low-inertia induction motor fans, resulting in reduced power consumption.

Multiple condenser fans can be grouped and controlled simultaneously by a single proportional controller.

The panel-mounted power analysers with plug-in modules offer high performance and built-in flexibility, making them ideal primarily for main metering applications.