PKG-SVX027C-EN
53
Water Flow Switch Option
A water flow switch is required to be installed in the
condenser water pipe within the unit; it can be supplied
from the factory as an option or it can be field-
provided. Whenever the flow switch detects a water
flow loss prior to or during mechanical cooling,
compressor operation locks out and a diagnostic code
displays. If water flow is restored, the compressor
operation automatically restores.
Waterside Economizer Option
The waterside economizer option takes advantage of
cooling tower water to either pre-cool the entering air
to aid the mechanical cooling process or, if the water
temperature is low enough, provide total system
cooling.
The waterside economizer includes a coil, modulating
valves, controls, and piping. The coil construction is
½-inch (13 mm) OD seamless copper tubes expanded
into aluminum fins. The evaporator and economizer
coils share a common sloped (IAQ) drain pan. Drain
pan options are either galvanized or stainless steel, and
insulated.
The tubes are arranged in a staggered pattern to
maximize heat transfer. The coil has round copper
supply and return headers with removable clean-out
and vent plugs.
Figure 38.
Basic water piping, constant water flow
Condenser 2
Condenser 3
Condenser 4
Condenser 3
Condenser 4
Condenser 2
WSE
Condenser 1
Condenser 1
Basic water piping, constant water flow
Basic water piping, constant water flow
with WSE
Heat Mode
The BAS Heat option consists of a fin and tube hot-
water coil, an electrically actuated ball valve, and
control software.
When the MSC Operating Mode is set to BAS HEAT,
the UC600 controller ends any Cooling Mode operation
(Mechanical and/or Water Side Economizer) and
transitions to control Discharge Air Temperature to the
BAS HEAT setpoint temperature. The UC600 does this
by opening and closing the Heating ball valve. The Fan
Array is controlled normally to maintain static pressure
to the Static Pressure Setpoint.
If the Discharge Air Temperature exceeds 104°F a
Manually Resettable High Discharge Air Temperature
Diagnostic is annunciated.
High Duct Temperature Thermostat
An optional factory-supplied temperature limit switch
with reset element detects the supply air duct
temperature. This sensor should be field-installed
downstream from the discharge in the supply air duct.
If the supply air duct temperature exceeds 240°F (115.6°
C), the unit shuts down and displays a diagnostic. A
manual reset is required at the unit. High duct
temperature can be adjusted at thermostat.
Dirty Air Filter Sensor Option
A factory installed differential pressure sensor senses
the pressure differential across the filters. When the
differential pressure exceeds a user selectable setting
will display a diagnostic. The unit will continue to run
until you replace the air filters.
Supply Air Static Pressure High Limit
During normal operation, the Supply Air Static is
monitored. If at any time the static pressure exceeds
the software high static limit (defaulted at 2.0 inches
from the factory) the unit will immediately shut down
and generate a diagnostic.
In order for the unit to resume operation, the Alarm
Reset must be toggled from the TD7. The software high
static limit can be user adjusted at the TD7.
