Airedale Condensing Units (CU) 3kW - 80kW - Manual (Page 4)

CU 1
– 4
Condensing Units
4
Condensing Units
Technical Manual : 904-020 v1.3.0 02_13
General Description
REFRIGERATION Cooling Only Heat Pump
Each unit features as standard: Each unit features as standard:

Liquid Line shut off valve

Liquid shut off valve

Suction Line shut off valve

Suction shut off valve

High & Low pressure switches

High & Low pressure switches

Filter drier (loose)

Filter drier biflow (loose)

Operating Charge

Reversing valve

Defrost function

Oil sump heater

Suction line accumulator

Check valve (TEV inbuilt)

Externally equalised bi-directional
thermostatic expansion valve
CONTROLS A custom designed microprocessor system has been developed and is fitted to the units as
standard so that an Airedale indoor unit can be matched to the Condensing unit, and
communication is available via a simple 2-wire link.
As standard the microprocessor is programmed with compressor anticycle protection, to
prevent short cycling and subsequent additional wear on the compressor, limiting the
compressor starts to 6 per hour.
As an additional feature, communication between indoor and outdoor microprocessor units is
carried by means of a low voltage 2 core screened cable.
A set of volt free contacts, to relay a unit trip, is provided as standard.
Alternatively, the condensing unit can be supplied with electro-mechanical controls – refer to
Optional Extras for details.
ELECTRICAL The unit control panel is fitted with the necessary contactors, sub-circuit protection and
terminals to allow efficient and continuous unit operation.
All wiring is colour coded and numbered for identification and all units are wired to current local
and European standards.
HEAD PRESSURE
CONTROL Head pressure is maintained by a factory fitted head pressure controller which varies the
speed of the fan(s) to provide optimum control under varying ambient conditions.
MAINS ELECTRIC
ISOLATOR To ensure complete unit isolation of the electrical panel during adjustment and maintenance.
The factory-fitted isolating device is a door interlocking type, preventing the panel from being
accessed when the unit is running.
OPTIONAL EXTRAS
Epoxy Coated Condenser
Coils In atmospheres where high corrosion is anticipated epoxy coated aluminium finned coils can be
fitted.
Wall Mounting Brackets To allow wall mounting a bracket and fixing kit can be supplied.
Defrost Drain Tray A stainless steel drain tray can be provided to collect condensate when units are used in heat
pump mode. Recommended for wall mounted installations.
Hot Gas Bypass To achieve capacity control during low load conditions or to maintain suction pressure when
used with fresh air systems, the hot gas bypass system will modulate the capacity down to
40% of full load. A stub is provided for site connection of the hot gas line to the local expansion
device. The hot gas option is supplied as a loose field fit kit.
Electro-Mechanical
Controls The condensing unit can be supplied with electro-mechanical controls to operate via a
cooling/heating signal from the indoor unit. This is suitable where the condensing unit is
matched to a non-Airedale indoor unit.
Phase Rotation
Protection A phase sequence relay is available for units containing 3 phase scroll compressors, to
prevent possible damage by running the compressor in the wrong direction.