DCN: 141-00240-02 7/03 2
Introduction
The ZC2S two zone HVAC Control Unit allows 2 standard electronic thermostats to connect to a single heating
and cooling HVAC mechanical system. It provides two independent “zones” of temperature control by controlling
the mechanical system and motorized dampers in each zone.
The ZC2S is for use with any residential style standard gas or electric heating HVAC system up to 5 ton
capacity. The control unit supports one stage heating and one stage cooling systems.
The two zones are truly independent and can be in either heating or cooling modes. The control unit features
auto changeover from heating to cooling modes and gives heating calls priority.
The ZC2S operation is fully automatic and transparent to the user. Each zone thermostat provides the complete
and independent control for that zone. You can think of each zone as having a separate heating/cooling system
with its own thermostat.
Each zone Thermostat determines the operation of the heating and cooling system so you should refer to your
Thermostat Manual for information on how to “operate” the system.
Thermostats for use with the ZC2S
The ZC2S works with most ELECTRONIC thermostats (Honeywell, White Rogers, Lux). Use only thermostats
that are either battery operated or that use both sides of the 24VAC power (they have R and C terminals)
from the HVAC system
DO NOT USE POWER STEALING THERMOSTATS!
Typically these thermostats “steal” power from the “W” or Heat connection on the HVAC system. THESE WILL
NOT WORK WITH THE ZC2S ZONE CONTROL UNIT.
It is also recommended that you do not use older style mechanical thermostats that use “anticipator” circuits as
these will not function properly.
Thermostats connect to the zone control unit terminals the same as they would connect to the HVAC system.
Zone Dampers for use with the ZC2S
The ZC2S provides independent control of temperature by regulating the flow of conditioned air to the zones by
motorized dampers. The system uses two position, on/off control.
The controllers are designed to work with normally open, two position, spring return, 24VAC, 2 wire motorized
dampers, such as the RCS RD Series of round motorized dampers. These dampers draw .5A each.
Normally open dampers are used to provide fail-safe operation, assuring condition air will be available even if a
damper motor fails. When zone 1 calls for heating or cooling, the zone 2 damper closes.
Maximum rated current for all dampers is 1 Amp. ( typically 2 dampers).
HVAC Systems Compatibility
The ZC2S is designed to work with most standard gas/electric residential style heating and cooling systems and
provide the following outputs to the HVAC system.
One stage of heating: W output
