Demand Control Overview - Mitsubishi Electric PUHY-P200 Service Handbook

[2-5 Demand Control Overview ]

2-5

Demand Control Overview

(1) General outline of control
Demand control is performed by using the external signal input to the 1-2 and 1-3 pins of CN3D on the outdoor units (OC,
OS1, and OS2).
Between 2 and 12 steps of demand control is possible by setting DIP SW6-8 on the outdoor units (OC, OS1, and OS2).
No Demand control switch
(a) 2 steps(0-100%)
(b) 4 steps(0-50-75-100%)
(c)
(d)
(e) 8 steps(0-25-38-50-63-75-88-100%)
(f)
(g)
(h) 12 steps(0-17-25-34-42-50-59-67-75-
84-92-100%)
*1. Available demand functions
P200-P500YKB models (single-outdoor-unit system): 2 and 4 steps shown in the rows (a) and (b) in the table above only.
P400-P900YSKB models (two-outdoor-unit system OC+OS1): 2-8 steps shown in the rows (a), (b), (c), and (e) in the table
above only.
P950-P1350YSKB models (three-outdoor-unit system OC+OS1+OS2): 2-12 steps shown in the rows (a)-(h) in the table
above.
*2. External signal is input to CN3D on the outdoor unit whose SW6-8 is set to ON. When SW6-8 is set to OFF on all outdoor
units, the signal is input to the CN3D on the OC.
Outdoor units whose SW6-8 is set to ON are selectable in a single refrigerant system.
*3. If wrong sequence of steps are taken, the units may go into the Thermo-OFF (compressor stop) mode.
Ex) When switching from 100% to 50%
(Incorrect) 100% to 0% to 50% : The units may go into the Thermo-OFF mode.
(Correct) 100% to 75% to 50%
*4. The percentage of the demand listed in the table above is an approximate value based on the compressor volume and
does not necessarily correspond with the actual capacity.
*5. Notes on using demand control in combination with the low-noise mode
To enable the low-noise mode, it is necessary to short-circuit 1-2 pin of CN3D on the outdoor unit whose SW6-8 is set to
OFF.
When SW6-8 is set to ON on all outdoor units, the following operations cannot be performed.
Performing 4-step demand in combination with the low-noise operation in a single-outdoor-unit system.
Performing 8-step demand in combination with the low-noise operation in a two-outdoor-unit system.
Performing 12-step demand in combination with the low-noise operation in a three-outdoor-unit system.
(2) Contact input and control content
1) SW6-8: OFF (Compressor ON/OFF, Low-noise mode)
CN3D 1-3P
Open
Close
CN3D 1-2P
Open
Close
*1. When SW6-8 on the outdoor unit in one refrigerant circuit system is set to ON , this function cannot be used.
*2. This function and the 4 levels or 8 levels on-DEMAND function can be used together. Input the order to CN3D 1-2P on
the outdoor unit whose SW6-8 is set to OFF.
HWE14040
DipSW6-8
OC
OFF
ON
OFF
OFF
ON
ON
OFF
ON
*1
Compressor ON/OFF
Compressor ON
Compressor OFF
*2
Low-noise mode
OFF
ON
Input to CN3D *2
OS1 OS2
OFF OFF OC
OFF OFF OC
ON OFF OS1
OFF ON OS2
ON OFF OC and OS1
OFF ON OC and OS2
ON ON OS1 and OS2
ON ON OC, OS1, and OS2
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