Daikin DCM601A51, Технические данные инструкция

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44 1.3 Explanations of Power Proportional Distribution
Power Proportional Distribution (PPD) ED721208
1.3.2 Count Accuracy
(1) Cause of error
(System example)
<Case of arising error>
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W1 + W2 Count conclusive total for indoor unit #1~#8 Refer to the “REASON”
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W1
≠
Count conclusive total for indoor unit #1~#5
W2
≠
Count conclusive total for indoor unit #6~#8 Refer to the next page
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W1 + W2 Count conclusive total for indoor unit #1~#8* : The reason to get and the error size
„
REASON
iTM counts every one hour’s power consumption.
Though fraction in case of computation occurs at this time, it is computed after leaving off a 1-W figure to avoid the risk
for the owners. As a result, the error by the leaving-off occurs by 0.5W/ hour in average value as per each indoor unit.
(Calculation example)
(1) Count for errors in 8-day
Tenant A + B : 0.5 (Wh) × 24 hr × 8 days × 5 units = + 0.48 kWh
Tenant C : 0.5 (Wh) × 24 hr × 8 days × 3 units = + 0.288 kWh
total = + 0.768 kWh
(2) Assuming that the reads on watthour meters are as follows:
W1: read on watthour meter = 490 kWh
W2: read on watthour meter = 200 kWh
total = 690 kWh
(3) Finally it is concluded as total error = 0.768 / 690 × 100 = 0.11%
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W1
≠
Count conclusive total for indoor unit #1~#5 :
W2
≠
Count conclusive total for indoor unit #6~#8 :
iTM counts the power consumption as the following conditions (1)~(6) for the standards. So, the gap to be raised from
these conditions may cause the error. Since these errors vary depending on the surrounded situations, the worst error
value cannot be drawn out from the computing.
(1) Combination rate of indoor units connected to an outdoor unit (100%)
(2) Outdoor air temperature ( 35°C)
(3) Indoor unit’s suction air temperature ( 19°C)
(4) Piping length ( 5m)
(5) Level difference ( 0m)
(6) Pipe diameter (
φ
22.2)
Watthour meter
(with output)
Power supply
3 phase
#1 #2 #3 #4 #5 #6
#: Indoor unit's address
#7 #8
W2
W1
Outdoor unit
Tenant A Tenant B Tenant C
Legend
: Read on wattmeter
iTM