Harmony Overview

Sequences up to 4 Fully Modulating Stages

The Harmony is the perfect control whenever multiple fully modulating stages are required. The Harmony controls the on/ off and the modulation of each stage to maintain precise set point control.

PID Type Logic

The Harmony's control algorithms allow it to look at the rate of change in the system. If the system temperature is changing quickly, the Harmony will react quickly to adjust the modulating stages' output. If the system temperature changes slowly, the Harmony will make slow and gradual adjustments. Therefore, the Harmony adapts to specific system requirements and minimizes fluctuations around the set point.

Controls 0-5 V, 0-10 V, 1-5V, 2-10V, or 4-20 mA modulating motors

The Harmony is designed to accurately control the output from 0 to 100% of modulation for each of these different types of motors. One Harmony can even control two different types of motors.

Only One Sensor

The Harmony requires only one sensor located in the common output header of all stages.

Digital Display of all System Settings

The Harmony's 80 character alphanumeric digital display names each system parameter in plain English and shows its precise value. The easy to follow menu system allows users to quickly make changes to any system setting without having to learn any specialized codes or keyboard commands. Password protection is available to prevent unauthorized users from making adjustments to control settings.

Automatic Rotation among Stages

Rotating the first stage to be activated on a call for output promotes even wear on each stage. The Harmony has three modes of rotation: Manual, First ON/First OFF, or automatically each time period which can be adjusted from every hour to every 7 days.

Outdoor Reset Control

The Harmony has an optional stand-alone hydronic outdoor temperature reset function.

Connects to Energy Management Systems

The Harmony can accept a 4-20 mA input signal from an EMS to adjust the temperature set point according to outdoor temperature, system requirements, or other factors. In addition, Harmony can be disabled by an Energy Management System (EMS) or other controller when there is no output requirement.

Monitors Stage Status

The Harmony is designed to accept a lockout signal from each stage. If any stage requires a manual reset, the Harmony will automatically skip it when adding more capacity. If a stage goes into lockout during normal operation, the next stage will be activated immediately to maintain the desired output capacity.

System Output is Active when Any Stage is Active

This output can be used to activate a system pump, combustion air damper, or perform any other function that is required when any stage is active. A System Prove input checks the status of components activated by the System output before stages can be activated.

Remote Communication Upgrade Available

The Harmony can be upgraded to the Visual Gold system to monitor and control all Harmony functions from a remote location. The Visual Gold upgrade also allows the Harmony to accept additional sensors, to monitor their status, and to provide alarms if the sensor values are not in the correct range.

Additional features include: A purge timer, a low fire adjustment, a firing point setting for the next stage based on the firing rate of the current stage, a lag stage timer, a last stage hold adjustment, and many others.

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Lochinvar operation manual Harmony Overview