Electrical Service; Air Cooled Condensers - Model Darc; Fluid Coolers - Model Dafc; Fluid-Sensing Thermostats - Data Aire MINI CEILING SERIES Installation, Operation And Maintenance Manual

Noise factors should be also considered when locating an air cooled heat exchanger. Proximity to
windows, walls, and surrounding structures can cause objections by the occupants. An acoustical
expert should be consulted when noise is of a particular concern.
Air cooled heat exchangers should be placed at a level that is higher than the indoor evaporator.
Mounting the remote heat exchanger (condenser or condensing unit) more than 10 feet below the
evaporator is not recommended. Excessive liquid line pressure drop can cause poor evaporator
performance.
Piping must be supported within 18 inches of the inlet and outlet connections. The inlet connection
is located on the top header on all remote heat exchangers and the outlet connection is located on
the bottom header of all units.
4.4

Electrical Service

Refer to Sections 3.1 to 3.5 for information regarding line voltage and control voltage wiring
details.
4.5

Air Cooled Condensers - Model DARC

Standard outdoor air cooled condensers have a fan speed controller on the fi rst fan. On single-
fan condensers this is the only means of control. A variable speed controller modulates the motor
speed based on system head pressure. The fan speed controller will normally not require fi eld
adjustment.
Air cooled condensers should be placed at a level that is above the level of the indoor evaporator.
Mounting a condenser or condensing unit more than ten feet below the evaporator is not recommended.
Excessive liquid line pressure drop can cause poor evaporator performance.
4.6

Fluid Coolers - Model DAFC

4.6.1 Fluid-Sensing Thermostats

Fluid cooler fan motors are cycled on and off by individual water-sensing thermostats strapped to the
leaving water header. The fan motor will only have a thermostat if the unit has an energy saver coil.
Without the optional energy saver coil, the fi rst fan motor runs whenever there is a call for cooling
via an auxiliary signal sent by the indoor evaporator (see also Section 3.5).
The water-sensing thermostats have adjustable setpoints which are typically staggered to maintain
water temperature in the 85 to 105
systems.

4.6.2 Energy Saver Cooling

In colder climates, the evaporator will often be equipped with an additional free cooling coil to take
advantage of the colder ambient temperatures. When incoming fl uid falls below the setpoint of a
water-sensing thermostat in the evaporator (typically about 50
available.
Systems with an energy saver coil should have at least one fl uid-sensing thermostat on the fl uid
cooler set lower to take advantage of colder ambient temperatures. The desired fl uid temperature
for energy saver cooling is 45
It is desirable to use the energy saver mode as much as possible. However, fl uid temperature that
o
F range. This is generally the desired range for glycol cooled
o
F. Field adjustment of fl uid-sensing thermostats is not unusual.
18
o
F), energy saver cooling becomes