ENGINEERING DATA
ACCESSORIES
February 1993
Supersedes
February 1992
HARMONY
II
Bulletin #480182
HARMONY
II
ZONE CONTROL SYSTEM
FOR VARIABLE AIR VOLUME HEATING/COOLING SYSTEMS
Harmony
II
Zone Control System
— Harmony II system is designed to provide up to
four separate heating/cooling zones utilizing a single indoor unit (G21V/GSR21V or
CB21/CBH21) and single outdoor unit (HS14 or HP21 two-speed). A single speed out-
door unit may be used for up to two zone applications. Two-speed outdoor unit may
be used for two, three or four zone applications. The system consists of the Harmony
control center, discharge air sensor, Harmony control panel, master thermostat and
duct mounted zone dampers with a thermostat in each zone. The zone dampers are
automatically controlled to supply air flow only to zones with a thermostat demand.
At the same time, the variable speed motor (VSM) in the G21V/GSR21V furnace or
CB21/CBH21 blower coil unit automatically adjusts the air volume to the zones as re-
quired. Because of the VSM motors’ ability to vary system air volume as required, no
bypass damper is required. Individual air volumes for heating or cooling are available
to each zone. Dampers are available in either round or rectangular configuration. Each
zone is sized for the heating/cooling load. Damper operation and blower air volume
is controlled by the control center. The Harmony system saves energy by allowing
temperature setback in unoccupied areas while maintaining comfort in occupied
areas. System also results in lower equipment costs by eliminating the need for two
separate heating/cooling systems. The Harmony Zone Control System may be used
in conjunction with the FM21 Heat Pump Control System and may also be used in
Smarthouse applications.
Control Center
— Control center (16J95) contains all necessary relays and controls to
operate the system. Control center cabinet is constructed of heavy gauge steel with a
enamel paint finish and removeable latching cover. Solid-state circuit board features:
low voltage output terminals for controlling up to four zones and indoor and outdoor
unit connections. Also has low voltage input terminals for up to four zone thermostats,
control panel, zone damper transformer, pressure switch and discharge air sensor.
Board also has jumper selectors for “Zone Air Volume Selection” (25-95%), “Heating
Air Reduction” (0%, 20% or 40%), “Continuous Air Reduction” (0%, 50% or 75%) and
“Discharge Air Temperature” (+ or – 5F heat or cool). LED’s on circuit board indicate
“Heating” (Red), “Cooling” (Green) for each zone and “Reversing Valve” (Amber).
Additional LED’s (Red) on board indicate “Zone Damper Operation”, “Indoor Unit Op-
eration”, “Blower Operation” and “Outdoor Unit Operation”. Four diagnostic LED’s are
furnished as an aid in servicing system. Board stores last two diagnostic codes for easy
servicing. Built-in time delay function prevents short cycling of system. Holes for
mounting are furnished and electrical inlets are provided in top, bottom and rear of pan-
el. Dimensions: 13-1/4” x 10” x 1-3/4”. Power requirements: 24VAC. Control center is
powered by indoor unit transformer. Shipping weight: 6 lbs.
Control Panel
— Touch sensitive panel (16J96) features: “Zone”, “Central” or “System
Off” control mode selection, “Cool”, “Auto” or “Heat” mode selection and “Auto“ or
“On” fan control for continuous or intermittent blower operation. LED indicators show
selected features at a glance. Panel is constructed of high impact Cycolac. Dimensions:
3-1/2” x 4-3/4” x 1-5/16”.
Discharge Air Sensor Probe
— Probe (16J98) is required for field installation. Probe
contains three sensors that monitor air temperature in the supply air stream. Sensors
send a temperature average to the control center to control blower motor speed.
System Equipment Data
— See flow charts on page 4 (gas heat) and page 5 (heat
pump) for system equipment selection. For G21V/GSR21V series furnace data, see
section Heating Units — Gas. For HS14 series two-speed or other single speed con-
densing units data, see Cooling Units — Condensing Units section. For add-on evapo-
rator coil unit data, see section, Cooling Units — Coils-Blower Coil Units. For HP21 se-
ries two-speed or other single speed heat pump outdoor units data, see Heat Pumps
— Matched Remote Systems section. For CB21/CBH21 blower-coil unit data, see sec-
tion, Cooling Units — Coils-Blower Coil Units. For EMD14-65 or EMD14M-65 Econo-
mizer dampers, see Accessories section.
Sequence of Operation
— Two modes of operation are available at the control panel
— a “Central” control mode and a “Zone” control mode.
In the “central” mode, heating or cooling selection and temperature demand are con-
trolled by the zone 1 (master) thermostat, all dampers remain open at mechanically
preset openings and blower is controlled by the central control board (total zone air
volume), delivering air to all zones.
In the “zone” mode, heating or cooling selection is controlled by the control panel (or by
the individual zone thermostats if system is set for auto-changeover), temperature de-
mand is controlled by the individual zone thermostats, zone dampers route air to ap-
propriate zones and blower air volume is adjusted according to central control jumper
setting and number of zones operating.
Individual air volume for each zone is preset at the control center and may be adjusted
from 25% to 95% actual air volume. During heating mode, Heating Air Reduction jumpers
allow a lower heating air volume to be selected (0%, 20% or 40% reduction of cooling air
volume). During continuous (“On”) blower operation, Continuous Air Reduction jump-
ers allow 0%, 50% or 75% air volume reduction. All dampers remain open if there is
no demand from thermostats.
NOTE — Specifications, Ratings and Dimensions subject to change without notice. 1993 Lennox Industries Inc.
ZONE SYSTEM
CONTROL
CENTER
(cover removed)
ZONE SYSTEM
CONTROL
PANEL
ZONE SYSTEM
CONTROL
CENTER
(cover in place)
POSITION
ONLY
POSITION
ONLY
POSITION
ONLY
To Next Page
Need help?
General
