Product data

4
Factory-installed options
Electro-mechanical controls include an electro-
mechanical controller with a 24-v transformer. The con-
troller requires a 24-v thermostat which can be supplied
loose for onsite wall mounting. Thermostat options include
cooling only or cooling and one stage auxiliary heat. Only
single fan speed thermostats can be used with this option.
Units are wired for medium speed. Wiring may be field
modified if high or low fan speed is desired.
Microprocessor controls include a custom designed
microprocessor fitted to the cassette to enable room condi-
tions to be maintained at a user-defined set point. Commu-
nication to the controller is by a handheld infrared
transmitter or a wall-mounted 'pendant' transmitter. Each
type of transmitter includes a standard wall mounting
bracket.
The microprocessor allows five operating modes: fan
only, dry cooling, cooling only, heating only, and heating/
cooling with auto changeover for maximum versatility. A
temperature set point between 58 F and 90 F can also be
selected.
The microprocessor monitors indoor coil temperature
and return-air temperature. The receiver contains a self
diagnostic feature. When a low indoor coil temperature is
detected, the cooling action is stopped. If a sensor fails
then an alarm is displayed on the fascia-mounted receiver.
The microprocessor is controlled with either an infrared
transmitter or pendant transmitter, depending on the trans-
mitter type selected at the time of order. A chip is factory-
installed in the unit control board which operates exclu-
sively with the type of transmitter selected.
The infrared or pendant transmitter is used to switch the
unit on/off, change temperature settings, fan speed, oper-
ating mode, and to toggle the motorized air sweep (where
fitted).
The microprocessor also has an built-in clock which can
be activated to enable the unit to be programmed with up
to two separate operating periods for the days of the week
(Mon-Fri). The clock provides ON/OFF unit operation and
is not a night set back or occupied/unoccupied control
function. Mon-Fri will operate as a 'block' of days and
cannot be programmed independently of one another.
Saturdays and Sundays can each be programmed with up
to two separate operating periods and are programmed
independently of the weekdays and each other.
A fascia-mounted receiver displays on/off, cool or heat,
and timer/alarm status.
Electric heat (single stage) includes fitted heating ele-
ments manufactured for maximum surface area and lower
working temperature for improved reliability. Thermal cut-
out protection switches are fitted to the electric heat circuit
to protect against overheating. The optional electric heat-
ing elements are available with the 208/220/230-v model
units only.
Hot water heat includes hot water heating coil factory fit-
ted to the standard chilled water coil to provide heating.
The coil is manufactured from copper tubes with mechani-
cally bonded aluminum fins. The hot water heat option is
not available on unit size 12.
Hot water coil freeze protection sensor is mounted to
prevent freezing of the hot water coil assembly. When the
sensor detects a freeze up condition, it will force the flow
control valve open and prevent the unit fan(s) from
running.
Disconnect switch (non-fused) is factory installed on
the control panel exterior and sized for the full load amper-
age of the unit to enable the unit to be disconnected from
the power supply prior to any maintenance.
Field-installed accessories
Chilled water/hot water control valve includes a
three-way, three-port diverting type valve or a two-way,
two-port control valve for control of chilled water or hot
water flow. Valve is supplied loose. Actuation is via a
24-v signal from the unit's electrical panel.
On a four-pipe system where two-way valves are speci-
fied, the chilled water valve will be a normally closed type.
The hot water valve will be a normally open type. Where
three-way valves are specified, the same type valve will be
supplied for both coils and should be installed normally
closed to the coil in the case of the chilled water coil and
normally open to the coil in the case of the hot water coil.
On a two-pipe changeover system where a two-way
valve is specified, a normally closed valve is supplied.
Where a three-way valve is specified, this should be
installed normally closed to the coil. In both cases, a pipe
mounted changeover thermostat can also be supplied to
monitor water supply temperature and allow action of the
valve.
Fresh air intake can be achieved by removing any num-
ber of the two or three (size dependent) fresh air knockouts
on the cassette chassis. Each individual knock-out accom-
modates 20 cfm of fresh air. A duct collar is available for
fastening to the unit to allow connection of a 3 in. flexible
duct.
Duct collars are available to allow connection of a 5 in.
or 6 in. (depending on unit size) flexible duct to the cas-
sette. Branch ducting can be achieved by removing the
branch duct knockouts and connecting flexible ducting for
circulating a limited amount of conditioned air. For unit
sizes 08,12, a total of three knockouts are positioned on
three of the unit sides (one per side). For unit sizes 18-36,
ITEM
FACTORY-INSTAL L E D
OPTIONS
FIELD-INSTA L L ED
ACCESSORIES
Electro-Mechanical Controls X
Microprocessor Controls X
Electric Heat X
Hot Water Coil X
Hot Water Coil Freeze
Protection Sensor
X
Disconnect Switch X
Chilled Water/Hot Water
Control Valve
X
Fresh Air Intake Duct Collar X
Branch Duct Collars X
Spare Filters X
Shroud X
Wall-Mounted Pendant X
Thermostats X
Aquastat X
Options and accessories