General Specifications - McQuay MDB075B Manual

General Specifications

Unit
The casing is constructed with electro-galvanised mild steel sheet which provides a rigid cabinet. The
internal components are easily accessible by removing the front panel. The finishing of the casing is a
long-lasting epoxy polyester powder coating.
Condenser Coil
Each coil consists of staggered rows of 3/8" OD seamless copper tubes, mechanically expanded into
die-formed corrugated aluminium fins. Each coil provided with integral sub-cooling circuit to maximize energy
efficiency and promote superior match-system operating performance when connected to suitably sized DX
Evaporator-blower unit. Coils are leak and pressure tested to 450 psig, evacuated and dehydrated.
Condenser Fan And Motor
The outdoor propeller fan is constructed from aluminium material and direct-driven by weatherproof three
phase induction motor. Fan motor has class F insulation (155°C). Fan is protected with steel guard.
Compressor
High efficiency, refrigerant-cooled, reciprocating/scroll hermetic compressor has internal suspension system
to eliminate noise, vibration and further resiliently isolated from unit base. Compressor has internal overload
protection. Units are provided with auto reset high-low pressure cut-outs and crankcase heater for off-cycle
operation to guard against compressor valve plate damage during start-up.
Safety Controls
Manual/Auto reset high pressure and low pressure cut-outs to guard against compressor damage due to
high discharge head pressure and system leakage respectively. Crankcase heater for each compressor to
prevent liquid migration, which can damage compressor valve plates, during off-cycle and eases start-up.
Sequential Controller Functions
(Standard for cooling and heatpump models and optional for cooling only units)
1. Sequential controller LCD display
A : Time display
B : Error indication
C : Compressor running display (up to 4
compressors)
D : Key lock display
E : Heater display (up to 2 heaters)
F : Energy saving mode display
G : Compressor defrost cycle display (up to
4 compressors)
H : Operation mode display
I : Temperature set display
3