Home Automation RC-120

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Summary

Introduction to the Thermostat

Thermostat Description and Features

Thermostat Operation Guide

Thermostat Display Overview

Details the main display area and its functions, showing time, temperature, and mode.

Hold Functionality

Sets the thermostat to maintain current settings, overriding programmed schedules.

Programming and Mode Keys

Accesses time/day settings, temperature schedules, and system mode selection.

Fan Control Settings

Manages fan operation between Auto mode and continuous On.

Temperature Adjustment Buttons

Utilizes Up and Down arrow keys for setting desired temperatures.

Understanding the Thermostat Display

Primary Display Information

Shows current time, temperature, and status indicators like DESIRED and OUTSIDE.

Operational Status Icons

Explains icons for system mode, fan, remote, hold, and schedule periods.

Anticipation Feature Explained

Programmable Energy Saver Mode (PESM)

System Mode and Remote Control

Power Outages and Clock Behavior

Two Year Limited Warranty Information

The RC-120 is an electronic communicating thermostat designed for two-stage heating and cooling systems. It offers both local and remote control capabilities, programmability, standalone operation, and robust, optically isolated communications with automation systems, utility control systems, and personal computers.

Function Description:

The thermostat's primary function is to precisely control the temperature in a building by managing two-stage heating and cooling systems. It allows users to set desired temperatures and schedules, ensuring comfort and energy efficiency. The device can operate in various modes: Off, Heat, Cool, and Auto. In "Off" mode, both heating and cooling systems are inactive. In "Heat" mode, the system maintains the desired heating setting. In "Cool" mode, it maintains the desired cooling setting. "Auto" mode enables the thermostat to automatically switch between heating and cooling to maintain both desired settings. The fan operation can also be controlled, with "Fan Auto" running the fan only when heating or cooling is active, and "Fan On" running it continuously.

The RC-120 incorporates an "anticipation" feature, a sophisticated control system designed to maintain comfort while saving energy. This feature anticipates the need to turn the system on or off before the temperature actually reaches the set point. When heating, it prevents air overheating by briefly turning off the heat while wall temperatures catch up, ensuring comfort without energy waste. In cooling, it periodically runs the system to circulate air and remove humidity even when the temperature is close to, but not above, the cool setting, allowing for comfort at higher cool settings and saving energy. The thermostat also logs the runtime of the heating and cooling systems to provide a "FILTER REMINDER" when it's time to replace the filter.

Important Technical Specifications:

The document does not explicitly list detailed technical specifications such as voltage, current ratings, or communication protocols, but it highlights key functional aspects:

System Compatibility: Two-stage heating and cooling systems (2 Stage Heat / 2 Stage Cool).
Communication: Optically isolated communications with automation systems, utility control systems, and personal computers.
Programmability: Up to 4 temperature settings per day (MORN, DAY, EVE, NITE) for weekdays, Saturdays, and Sundays. Time increments for programming are 15 minutes.
Time Keeping: The internal clock is maintained for approximately 25 minutes during an electrical outage. All settings and programs are stored permanently and are not affected by power outages.
Compliance: Listed by Underwriter's Laboratories and UL Canada. Complies with European Union requirements for Electromagnetic Interference, Electromagnetic Immunity, and Safety (EMI and Low Voltage Directives). Also complies with FCC Rules, part 15, for Class B digital devices.

Usage Features:

Display: The LCD display shows current time, temperature, desired temperature, outdoor temperature (optional), and the current mode. Icons indicate system status (e.g., "HOLD," "MORN," "DAY," "EVE," "NITE," "REMOTE," "OFF," "COOL," "HEAT," "FAN," "AUTO," and stars for heating/cooling stages).
User Interface: Features dedicated keys for "Hold," "Prog" (programming), "Mode," "Fan," and Up/Down arrows for temperature adjustment.
Hold Mode: Allows users to set the system into "Hold" mode, preventing programmed settings from changing the temperature.
Programming Mode: Accessed by pressing the "Prog" key multiple times. Allows setting current time and day, and programming temperature-time schedules for MORN, DAY, EVE, and NITE periods across weekdays, Saturdays, and Sundays.
Day/Night Mode: Can be configured to change temperature settings between "DAY" and "NITE" when commanded remotely.
Programmable Energy Saver Mode (PESM): Allows a remote system to override the thermostat's settings. "REMOTE" is displayed when the remote system has control. In this mode, local thermostat controls are disabled until the energy saver feature is turned off at the remote system.
System Mode: When connected to an automation system or personal computer, the remote system can send commands to change mode, cool/heat settings, fan status, and hold status. Local changes override remote commands, and pressing "Hold" prevents further remote changes.
Automatic Time Update: The thermostat time can be automatically updated by a connected automation system.
Filter Reminder: Displays "FILt" every four seconds when it's time to change the filter. Pressing the "Prog" key clears the reminder.

Maintenance Features:

Maintenance-Free Design: The thermostat is designed to be maintenance-free, with no batteries to install or replace.
Cleaning: Can be cleaned carefully with a mild soap solution on a soft cloth.
Filter Reminder: Provides a reminder when the air filter needs to be replaced, based on system runtime.

The RC-120 is designed to be a reliable and user-friendly thermostat, offering advanced control and communication capabilities for modern heating and cooling systems.