21
S1CV / S1HV Condenser Operation
• When indoor control is placed in Cooling Mode, with
set point temperature below room temperature,
compressor, outdoor fan, and indoor blower energize.
• Anti-short cycle timer (ASCT) prevents compressor from
re-starting for three minutes.
• When indoor control is placed in Heating Mode, with
set point temperature above room temperature,
compressor, outdoor fan and indoor blower energize.
• Heat pump defrost control is designed to keeping
outdoor coil free from frost and ice buildup. Through
control of reversing valve, compressor speed, outdoor
fan speed, and indoor optional electric heat. Defrost
is initiated when outdoor coil sensor has accumulated
90 minutes of compressor run time with coil operating
below 30ºF (-1.1ºC). When coil sensor reaches 60ºF
(15.5ºC), due to either defrost cycle or increase in
ambient temperature, timer is reset to zero (0) minutes.
• Upon defrost initiation, reversing valve shifts to Cooling
Mode with outdoor fan Off, indoor blower and optional
electric heat (if available) On. Hot gas from compressor
melts frost and ice on outdoor coil and electric heat
tempers indoor air, until outdoor coil sensor reaches
60ºF (15.5ºC) or 10 minutes has elapsed. System
reverts to normal heat pump operation. Defrost times
vary depending on outdoor temperature, wind, and
moisture conditions.
• In Cooling Mode reversing valve is energized at all
times. When air handler calls for cooling, if compressor
is not in ASCT, it will start softly then increase speed as
necessary to balance indoor cooling load with outdoor
ambient, while minimizing number of compressor
starts and stops. Actual compressor speed is based on
room temperature differential, indoor fan speed, and
compressor rated frequency parameters. Minimum
compressor run times and indoor coil freeze protection
are in place whenever compressor runs in Cooling Mode.
Condenser mounted Electronic Expansion valve (EXv)
continuously adjusts refrigerant flow to maintain 15ºF
(8.3ºC) superheat at compressor. Expanded refrigerant
froth travels through small diameter tube of line set to
air handler where heat is transferred into refrigerant.
Once refrigerant evaporates, super-heated vapor returns
to condenser via large diameter tube. Refrigerant
expansion occurs in outdoor unit, both tubes in line set
require insulation.
• As temperature of indoor space moves closer to set
point compressor, indoor, and outdoor motors adjust
• EMI Series condensers will only operate with EMI Series
air handlers.
• Systems can be configured as either single source power
(air handler without electric heat fed from condenser) or
double sourced power where each component receives
power independently protected by field service HACR
fuse/breaker. See unit name plate for the correct HACR
fuse/breaker, breaker type and size.
• Outdoor and indoor units are connected to each other
through low volt interconnect wiring. 24v transformer
located in indoor unit provides low volt power.
• Indoor set point temperature range is adjustable
between 55° and 90ºF (13 – 32ºC) in one degree
increments.
• Controls store configurations and settings in non-volatile
memory, not lost in power outage with selectable re-
start feature.
Straight cool condensers are designed to operate as single
stage DX cooling unit.
Heat pump condensers are designed to operate as single
stage DX cooling and heating system.
Two stage heating, air handler must be equipped with
optional electric heat.
Proper system operation requires condenser to be matched
with appropriate indoor unit using either standard hand
held remote or optional Wired Wall Controller.
Heat pump condensers utilize reversing valve to provide
reverse cycle (heating) operation.
Outdoor unit acts as either condenser or evaporator
providing cooling or heating to indoor space based on mode
of operation and ambient conditions.
Reversing valve is energized for Cooling Mode operation.
Should reversing valve fail to actuate, system will default to
Heating Mode of operation.
S1CV / S1HV IOM’s Sequence of Operation
CONDeNSeR OPeRATION
