Specifications

83
ENVISION COMMERCIAL SPECIFICATION CATALOG
Option: AlpinePure Hot Gas Bypass
The hot gas bypass (HGB) option is designed to limit the mini-
mum evaporating pressure in the cooling mode to prevent the
air coil from icing. The option shall consist of a hot gas bypass
valve installed in the discharge side of the compressor. The
refrigerant control shall proportionately bypass hot gas refriger-
ant to the air coil when suction pressure falls below 115 psig thus
limiting air coil freeze-up.
Optional AlpinePure Hot Gas Reheat
An optional hot gas reheat coil shall be available to allow
dehumidification-only operation. The internal reheat system
shall be factory installed and include a high efficiency reheat
coil located downstream of the evaporator coil, a reclaim valve
and integral controls to allow heating, cooling and reheat/dehu-
midification modes. The reheat coil shall be sized so that during
reheat/dehumidification mode the unit will produce neutral
air (78 ± 3 °F DB @ 50-58% relative humidity) with typical 80
DB/67 WB °F entering air and 90 °F entering water tempera-
ture. The reheat coil shall be sized to restrict airflow by no more
than 0.17 in wg at 350 feet per minute airflow velocity.
The FX10 control shall have three control options available:
Room wall dehumidistat – An optional room wall dehumi-
distat shall control the reheat mode thru a 24VAC ‘Hum’
input (On or Off). Setpoint and deadband shall be deter-
mined by the dehumidistat.
Duct humidity sensor – An optional duct humidity sensor
shall be installed. The FX10 control reads the humidity
from the sensor and determines operation mode. Setpoint
and deadband are internally set by the FX10 control and
shall be are adjustable. Continuous blower operation is a
requirement for this mode to accurately measure relative
humidity during the off cycle.
Room wall humidity sensor - An optional wall humidity
sensor is installed. The FX10 control reads the humidity
from the sensor and determines operation mode. Set-
point and dead band are internally set by the FX10 control
and are adjustable. Continuous blower operation is NOT
requirement for this mode.
Dehumidification Set Point (used only with a humidity
sensor) - The factory default set point for dehumidification
is 52% this is field adjustable from 30% to 60%. In addi-
tion there shall be a factory default differential of 5% field
adjustable from 5% to 15%. The control will enable re-heat
when the space humidity rises above the set point plus the
differential.
Reheat operation during periods of vacancy - The control
logic contains an unoccupied set point that can be used
for periods of un-occupancy if desired. The factory default
for the set point is 60% and is adjustable from 30% to 60%.
The unoccupied setback must be enabled either through a
building automation system or with a user interface. Fac-
tory default for unoccupied setback is off.
Space Humidity High and Low Alarm Limits (building auto-
mation system only) - The control has a high and low alarm
limit that can be enumerated over a building automation
system. The factory default set point for these alarm limits
is 0% for the low alarm and 100% for the high alarm limit.
These limits can be adjusted through a building automation
system.
Blower Motor and Assembly
The blower shall be a direct drive centrifugal type with a
dynamically balanced wheel. The housing and wheel shall be
designed for quiet low outlet velocity operation. The blower
housing shall be removable from the unit without disconnecting
the supply air ductwork for servicing of the blower motor. The
blower motor shall be a variable-speed ECM2 type. The ECM2
blower motor shall be soft starting, shall maintain constant CFM
over its operating static range, and shall provide 12 CFM set-
tings. The blower motor shall be isolated from the housing by
rubber grommets. The motor shall be permanently lubricated
and have thermostatic overload protection. ECM2 motors shall
be long-life ball bearing type.
Option: PSC Blower Motor - The blower motor shall be a three-
speed PSC type (single speed compressor models only).
Option: High static blower motors shall be available on certain
PSC and ECM models.
Electrical
A control box shall be located within the unit compressor com-
partment and shall contain a 75VA transformer, 24 volt activat-
ed, 2 pole compressor contactor, terminal block for thermostat
wiring and solid-state controller for complete unit operation.
Electromechanical operation WILL NOT be accepted. Units shall
be name-plated for use with time delay fuses or HACR circuit
breakers. Unit controls shall be 24 volt and provide heating or
cooling as required by the remote thermostat/sensor.
A Premier2 microprocessor-based controller that interfaces
with a multi-stage electronic thermostat to monitor and control
unit operation shall be provided. The control shall provide oper-
ational sequencing, blower speed control, high and low pressure
switch monitoring, freeze detection, hot water limit thermistor
sensing, condensate overflow sensing, auxiliary heat staging,
lockout mode control, hot water and loop pump control, LED
status and fault indicators, fault memory, field selectable op-
tions and accessory output. The control shall provide fault retry
three times before locking out to limit nuisance trips.
A detachable terminal block with screw terminals will be pro-
vided for field control wiring. All units shall have knockouts for
entrance of low and line voltage wiring. The blower motor and
control box shall be harness plug wired for easy removal.
Option: A FX10 microprocessor-based controller that interfaces
with a multi-stage electronic thermostat to monitor and control
unit operation. The control shall provide operational sequenc-
ing, blower speed control, high, low and loss of charge pressure
monitoring, freeze detection, condensate overflow sensing,
lockout mode control, hot water and loop pump control, LED
status and fault indicators, fault memory, field selectable op-
tions and accessory output. The control shall communicate all
mode, status, fault and lockout codes to the front end system
for fast and accurate equipment diagnosis. The control shall
provide fault retry three times before locking out to limit nui-
sance trips.
Optional FX10 microprocessor control communication proto-
cols: N2, LonWorks, BACnet
Optional IntelliStart
TM
(compressor Soft Starter) shall be factory
installed for use in applications that require low starting amps,
reduced compressor start-up noise, off-grid, and improved
start-up behavior. IntelliStart shall reduce normal starting cur-
rent by 60% on 208/60/1 units.
Piping
Supply and return water connections (and optional hot water
generator connections) shall be 1 in. [25.4 mm] FPT brass fit-
tings fixed to the corner post, which eliminate the need for
backup pipe wrenches.
Engineering Guide Specications cont.