309 B/C – 03/03 A – page
5/28
General Specification
Compressor
McQuay Mini Chillers M4AC080C(R) to M4AC150C(R) are equipped with highly efficient, reliable and silence scroll
compressors.
Air-Cooler Condenser
The air-cooled condenser coil consists of staggered rows of 3/8’’ O.D. seamless copper tube, mechanically expanded
into die formed aluminum fins to ensure optimum heat exchange capability.
Condenser Fan Motor
To achieve the high air change requirement, the unit is equip with the high air flow propeller fan. The fan is direct driven
by weatherproof motor to ensure reliable continuos operation.
Evaporator
The heat exchanger is made of stainless steel plates closely arranged and brazed together to ensure high heat
exchange efficiency. The complete heat exchanger is insulated with thermal insulation closed cell rubber foam to give
optimum thermal insulation.
Refrigerant Circuit
The refrigerant circuit is factory brazed and evacuated before accurately charged with HFC 407C to ensure optimum
operating requirement. To ensure flawless continuous operation, each refrigerant circuit is equipped with a carefully
sized capillary tube.
Additional Safety Protection
The units are equipped with intelligently designed safety control to ensure continuous safe operation. High and low
pressure switch is provided to prevent the compressor damage resulting from both abnormally high discharge head
pressure or low pressure due to insufficient gas. The compressors are provided with crank case heater to prevent liquid
migration during the off cycle and also to ease the start up of the unit.
The standard electronic controller provides accurate water temperature control in the circuit by closely monitoring and
reacting to the input from the water entering temperature, water leaving temperature and ambient air temperature.
Flow switch is provided in the unit to protect against damage to the water pump.
During abnormal condition, the electronic controller will turn the unit off and the then display the faulty of operation. (See
Troubleshooting
sheet)