Lennox Harmony III Manual

Harmony III Zoning System / Page 9
HARMONY III AND HUMIDITROL WHOLE HOME DEHUMIDIFICATION SYSTEM
HUMIDITROL ZONING ACCESSORY
The Humiditrol Zoning
Accessory is required
for proper operation
of the Harmony
III™ Zoning System
when used with the
Humiditrol
®
Whole
Home Dehumidication System (EDA). Refer to
Installation Instructions for detailed information about
system operation.
System Selector Switch
Three position switch on control allows three different
operating modes.
Position 1 - (EDA) Dehumidication demand has
priority over heating/cooling demands from
zones 2 - 4.
Position 2 - (ZONE) Heating/cooling demands for all
zones have priority over a dehumidication
demand. Factory setting.
Position 3 - (TIMER) Internal timer (non-adjustable)
will cycle system between dehumidication
demand and heating/cooling demand every
twenty minutes. Cycling only occurs when
there is a demand for both.
Thermostat
The zone 1 master room thermostat must be a “reverse
logic” type (outputs a 24 volt AC signal when there is
NO dehumidication demand and a 0 volt signal when
there IS a dehumidication demand).
The ComfortSense
®
7500 Thermostat meets these
requirements. See Optional Accessories Table for
selection.
Transformer
Five (5) volt-amps (VA) are required for the EDA
interface control which must be powered by the same
system transformer that powers the Zone Control
Board, thermostats, and zone dampers. See Optional
Accessories Table for selection.
Freezestats (Indoor Coil)
If the minimum air requirement for the EDA system
is less than 350 cfm per ton, it is recommended that
a freezestat be installed on the indoor coil to prevent
icing of the coil. The freeze-stat senses when suction
line temperature falls below its setpoint and cycles the
compressor off. The freeze-stat opens at 29°F and
closes at 58°F. See Optional Accessories Table for
selection.
Discharge Air Sensor
Discharge Air Sensor furnished with Harmony III Zone
Control Board must be installed on the outlet side of the
EDA system.
Outdoor Air Temperature Sensor
For proper operation of Harmony III Zone Control with
EDA applications, an outdoor air temperature sensor
MUST be installed.
Cabinet
The Humiditrol Zoning Accessory comes in a high
impact plastic case that matches the Harmony III control
panel.

Lennox Harmony III Specifications

General

Brand	Lennox
Model	Harmony III
Category	Control Systems
Language	English