Airedale OptiChill FreeCool 500kW - 1365kW - Manual (Page 37)

Chillers OptiChill Freecool
Chillers
37
Technical Manual : 7197700 v1.2.0 02_2013
General Description
Standard Features
Controls As standard, the microprocessor controller can provide 8 stages of
capacity control.
Optionally, the controller is designed to provide capabilities for;

Building Management Systems (BMS)

Sequencing (Master/Slave and Run/Standby)
to meet all your system requirements, please specify at order.
For further details, refer to Controls, on page 38.
Electrical
A weatherproof electrical power and controls panel is situated at the end of the unit
and contains:

Individual mains power compartments for each
refrigeration circuit
refer to Interconnecting
Wiring , on page 118

Separate door locking electrical isolation for each mains
compartment

Dedicated bus-bar chamber for connection of incoming 3-
phase and earth mains power supply,

Emergency Stop fitted to controls compartment door

Separate, fully accessible, controls compartment, allowing adjustment of control set
points whilst the unit is operational

Circuit breakers for protection of all major unit components

Phase rotation relay incorporating phase loss protection (compressor module)
The electrical power and control panel are wired to the latest European standards and
codes of practice.
Mains supply is 3 phase and a neutral is not required direct to unit busbar, refer to
Interconnecting Wiring , on page 118.
A separate 230V permanent supply is required for the controls and safety features.
Electrical terminals for external evaporator pipework trace heating (230V/500W)
are provided.
CAUTION A fused and isolated electrical supply of the appropriate phase, frequency and
voltage should be installed.
Electronic Expansion
Valves (EEV)
ES Electronic expansion valves differ to the normal thermostatic expansion valves in
their ability to maintain control of the suction superheat at reduced head
pressures. This can lead to significant energy savings particularly at reduced
loading and low ambient temperatures. Factory fitted, for full details refer to
Design Features & Information , on page 48.
Head Pressure Control -
Voltage Regulated
Electronic fan speed controllers are fitted which modulate the fan speed by means of
voltage regulation, maintaining an optimised condensing pressure, allowing the system to
operate in ambient temperatures as low as -20°C.
Head pressure can be set and monitored at the microprocessor display.