Lennox Harmony III User Manual

15
zone control transformer primary should be the same source as the air handler to
keep it uncomplicated.
• Use a 230VAC primary transformer with air handlers (CBX25UHV, CBX32MV,
CBA38MV and CBX40UHV)
• Use a 115VAC transformer with furnaces (SLP98, SL280V,EL296V and
SL297NV) and with CBWMV.
1. Connect the zone control transformer primary to the air handler voltage source.
2. Do not connect the zone control transformer secondary to the zone control
panel at this time.
3. Connect air handler secondary common to the assumed zone control
transformer common.
4. Measure voltage between air handler R and unconnected zone control
transformer secondary lead.
» if0volts(A,“Figure14.ConrmingTransformerPhasing(Polarity)is
Correct” on page 14) then polarity is correct; connect the leads to
zone control C and R as shown.
» if48volts(B,“Figure14.ConrmingTransformerPhasing(Polarity)is
Correct” on page 14) then polarity is reversed; swap leads as shown
andconrm0volts(C,“Figure14.ConrmingTransformerPhasing
(Polarity) is Correct” on page 14); connect the leads to zone control
C and R as shown.
5. With the correct polarity determined, connect C wire to zone control 24VAC C
terminal and R wire to R terminal.
1.12.2. Thermostat
Using standard electronic 1-heat/1-cool non-heat pump, non-power robbing
thermostats,andve-wirethermostatcable,wireunitsasfollows:
1. Wire each thermostat to terminals Y, W, G, R, and C.
2. Run cable from each of the thermostats to the zone control panel. Mark each
cable according to the zone thermostat from where it originates.
3. Stripthecablesandattacheachofthevewirestothezonecontrolpanel.
1.12.3. Gas Furnace
IMPORTANT
The common C terminal of the Harmony III zoning system zone control panel
MUST be connected to the common terminal of the integrated control, or if using
an air handler, MUST be connected to the common terminal of the air handler
terminal strip.
If not connected, blower may operate only at the minimum CFM or will not ramp
to zone air volume.
After the furnace is installed, eld wire the unit as described in the installation
instructions provided with the furnace. Use thermostat wire to connect the furnace
and the zone control panel and to connect the zone control panel 24VAC C to the
integrated control terminal strip C.
1.12.4. Air Conditioner Unit
Aftertheairconditionerunitisinstalled,eldwiretheunitasshownintheinstallation
instructions provided with the unit. Use thermostat wire to connect the AC unit to
the zone control panel.

Lennox Harmony III Specifications

General

Brand	Lennox
Model	Harmony III
Category	Control Systems
Language	English