Technical Manual Downflow - Airedale International Air Conditioning

GENERAL
8
-DF
General Description
STANDARD FEATURES
Head Pressure Control -
Intelligent Modulation
(X Models)
Head Pressure Control
(WX Models)
Precision Air Conditioning
Technical Manual : 6259014 v1.3.0 02_2013
Precision Air Conditioning
The system is fitted with a voltage regulating fan speed controller which allows set point
adjustment and system monitoring via the indoor unit
microprocessor controller.
A pressure transducer is fitted to the liquid line which in turn feeds back the head
pressure to the microprocessor. The condenser fan speed can then modulate via the
controller to provide optimum control under varying ambient conditions. The head
pressure can be monitored via the display keypad.
Units fitted with thermostatic expansion valves have the head pressure factory set to
17 barg (247 psig).
Units fitted with optional electronic expansion valves have the head pressure factory set
to 14 barg (203 psig).
A 3 way mechanical regulating valve senses the compressor head pressure and allows
cooling water to flow to the condenser, to by-pass the condenser, or to allow water flow to
both condenser and by-pass line in order to maintain correct refrigerant head pressure.
A pressure transducer is fitted to the liquid line which enables the head pressure to be
monitored via the display keypad.
Filters Pleated disposable panel filters in a rigid frame. Conform to BS EN 779-G4.
Access and removal from unit front.
As standard the microprocessor provides an alarm following a pre set run
time limit being exceeded, refer to Controls -Filter Change Alarm.
Electrical The control panel contains the necessary compressor starter contactors, transformer, sub
circuit protection, volt free contacts for a common alarm and mains and inter-connecting
terminals. The panel is situated within the cabinet and can be removed for essential
maintenance of other components within the unit. The electrical control panels are wired
to the latest European standards and codes of practice.
Sub Fusing The electrical mains supply for the system’s outdoor unit(s) is supplied via the indoor unit.
MCBs are fitted for protection.
Main Electric Isolator To ensure complete unit isolation of the electrical panel during adjustment and
maintenance a door interlocking isolator is provided as standard.
Controls Units are fitted with the microprocessor controller which offers powerful
analogue and digital control to meet a wide range of monitoring and control. Features a
communication port plus networking and BMS connections.
A 4 x 20 character backlit LCD display keypad assembly is used to view the unit status
and allow operator adjustment.
For full details, please refer to the Controls section.