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11
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(b) Pulse unit selection
1
Find the total capacity of all connected air conditioners
2
Assume that the correct electricity meter is being used
3
Air conditioners operating at full load: assume summer overload power consumption
⳯
1.2
For example, Set the total electricity consumption = 100kW, power rate = 90%
Operating at full load = 100
⳯
1.2 = 120kW
With 3 in conjunction, 1 = 120
⳯
1000/ (1.732
⳯
200
⳯
0.9) = 385A
→
Electricity meter must be 400A
If you use 400A Mitsubishi transmission equipment, then
• K11 type, pulse unit at 100kWh/P
select while at 10kWh/P
• K11 type, pulse unit at 100kWh/P
10kWh/P
select while at 1kWh/P
• There are other products with smaller pulses, ask an electric meter manufacturer for details.
4
Inspection while electricity consumption is at 120kWh
●
When pulse input is highest
Use 0.1kWh/P, then 1200P/h = 20P/min exactly 1 minute 20 pulse (300pulses or fewer)
10 minutes 200 pulses OK
Use 1kWh/P, then 120P/h = 2P/min exactly 1 minute 2 pulses
10 minutes 20 pulses OK
Use 10kWh/P, then 12P/h = 0.2P/min , so 1 minute no pulses
10 minutes 2 pulses OK
●
Lower usage rate, for example 1/10 time (12kWh),
Use 0.1kWh/P, then 120P/h = 2P/min so 1 minute 2 pulses
10 minutes 20 pulses OK
Use 1k h/P, then 12P/h = 0.2P/min , so no pulses in 1 minute
10 minutes 2 pulses OK
Use 10k h/P, then 12P/h = 0.2P/min , so 1 minute no pulses
10 minutes no pulse NG
5
Pulse units should reach 0.1kWh/P.
• 10kWh/P is NG.
• 1kWh/P usage rate is the lowest, there might not be any pulses in 10 minutes, causing a calculation error.
