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[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
HP72-HP120T/YNU models (single-outdoor-unit system): 2 and 4 steps shown in the rows (a) and (b) in the table above
only.
HP144-HP240T/YSNU models (two-outdoor-unit system OC+OS1): 2-8 steps shown in the rows (a), (b), (c), and (e) in the
table above only.
*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.
HWE18240_GB
DipSW6-8
OC
OS1
OFF
OFF
ON
OFF
OFF
ON
OFF
OFF
ON
ON
ON
OFF
OFF
ON
ON
ON
*1
Compressor ON/OFF
Compressor ON
Compressor OFF
*2
Low-noise mode
OFF
ON
Input to CN3D *2
OS2
OFF
OC
OFF
OC
OFF
OS1
ON
OS2
OFF
OC and OS1
ON
OC and OS2
ON
OS1 and OS2
ON
OC, OS1, and OS2
9
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