Midea MCCDH30A-TA3SL, Technical & Service Manual

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Air-cooled modular chiller unit
1
through address code on the electric control board. The address code 0 # is provided as the main unit. The priority of being
the main unit is given to the unit with digital compressor, and other addresses are subordinate units. Only the unit is chosen
as the main unit, its electric control can activate such functions as direct communication with the wired controller, refrigerating
and heating capability adjustment, pump control, auxiliary electric heater control, total effluent temperature detection and
water flow switch detection.
27 PWM pressure relieve valve control(For digital compressor).
28 Outdoor fan A, controlled by T4.
29 Outdoor fan B, controlled by T4.
30 Input of transformer, 220-240V AC current. (Only valid for the main unit).
31
Input of three-phase four-wire power supply (Fault code E1).
Three phases A, B and C of power supply should exist simultaneously, and the difference of phase angle should be 120º
among them. If the conditions are not met, fault of phase sequence or phase lack may occur, and fault code will be displayed.
When the power supply returns to normal condition, fault is removed. Attention: phase lace and phase dislocation of power
supply are detected only in the early period after the power supply is connected, and they are not detected while the unit is in
operation.
32
S7 ON: Remote control OFF
：
Wired control
S8 ON: Low temp. Mode OFF
：
Normal
S9 ON: 30KW OFF
：
65/130/200/250KW
33 Output of transformer.
CAUTION
1. Faults
When the main unit suffers faults, the main unit stops operating, and all other units also stop running;
When the subordinate unit suffers faults, only the unit stops operating, and other units are not affected.
2. Protection
When the main unit is under protection, only the unit stops operating, and other units keep running;
When the subordinate unit is under protection, only the unit stops operating, and other units are not affected.