Smarter, Connected HVAC Control: Meet the Enhanced Model 600 from Quest Controls

Managing HVAC systems at remote facilities just got a whole lot easier—and more cost-effective. Quest Controls is excited to announce a major upgrade to the trusted Model 600 Lead/Lag HVAC Controller: it now comes equipped with built-in Ethernet connectivity and expanded networking capabilities.

Whether you're overseeing a data center or a network of fiber huts, this enhancement gives you powerful tools to remotely monitor, configure, and optimize HVAC performance across your entire footprint—without costly site visits or complicated workarounds.

Why Ethernet Matters

The upgraded Model 600 supports Modbus TCP and includes a password protected web interface. That means you can now access HVAC settings and diagnostics in real time—from anywhere with a network connection. No more relying on local-only interfaces or waiting on field techs to make adjustments.

With Ethernet, your team gains:

• Remote Access: Monitor and configure HVAC operations remotely via Ethernet or Bluetooth, reducing truck rolls and site visits.
• Scalable Networking: Multiple Model 600 units can be networked together and connected to a Quest TELSEC® ESB2 or other Modbus poller for coordinated, site-wide HVAC control.
• Energy Optimization: Leverages Quest’s patented economizer control algorithm to reduce compressor runtime and maximize free cooling—resulting in lower energy bills and long-term operational savings.
• User-Friendly Interface: Features a web-browser interface for simplified configuration and monitoring as well as an intuitive display and keypad.

It’s all about delivering faster response times, fewer truck rolls, and better performance insight at the facility level.

Powerful Control, Scalable Architecture

At its core, the Model 600 still does what it’s always done best: managing two independent HVAC units in a lead/lag configuration with automatic failover and sequencing. But now, with networking support, you can:

• Connect multiple Model 600 units for larger or more complex environments
• Tie them into a Quest TELSEC® ESB2 or any Modbus-compatible system
• Coordinate HVAC operation across multiple zones or enclosures

This flexible architecture is especially beneficial for operations with diverse facility types or wide geographic distribution.

Built-In Energy Efficiency

The Model 600 isn’t just about control—it’s about cutting costs. With Quest’s patented economizer algorithm, the controller can reduce compressor use and make smart decisions based on ambient conditions. That means lower energy bills, longer equipment life, and greener operations.

Where You’ll Find the Model 600 in Action

The Model 600 is ideal for a variety of facility types, including:

• Medium Sites: Data Centers, Central Offices, Switching Centers, Headends
• Small Facilities: CEMHs, HUTs, WICs, Fiber Hubs, Substations

Wherever critical HVAC control is required, the Model 600 delivers the reliability, visibility, and scalability modern infrastructure demands.