Count Accuracy - Daikin VRV III-S Technical Data Manual

10 Explanations of Power Proportional Distribution

10 - 2 Count Accuracy

10 - 2 - 1Cause of error
System example
Power supply
3 phase
Power supply
single phase
HUB
PC
To other iPU
<Case of arising error>
≠
+
W1 W2
≠
W1 Count conclusive total for indoor unit #1~#5
≠
W2 Count conclusive total for indoor unit #6~#8
≠
W1 W2
• REASON 1
iPU 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 of all indoor units.
Calculation example
(1) Count for errors in 8-day
Tenant A + B : 0.5 (Wh) × 24 hours × 8 days × 5 units = + 0.480 kWh
: 0.5 (Wh) × 24 hours × 8 days × 3 units = + 0.288 kWh
Tenant C
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%
40
•
W2
Watthour meter
(with oscillator)
W1
iPU
Count conclusive total for indoor unit #1~#8
≠
Count conclusive total for indoor unit #1~#8*: The reason to get and the error size.
• VRV Systems • Network Solution
Outdoor unit
#1 #2 #3
Tenant A Tenant B
→ Refer to the next page
→ Refer to the next page
#4 #5 #6 #7
Tenant C
Legend : Read on wattmeter
#: Indoor unit's address
#8