Appendices
Appendix J - Core Measurement Parameters: Power Factor
110
Building Technologies
125-202
06/06/2017
Appendix K - Core Measurement Parameters - Power
Measurement Parameters: Power
BACnet
Object
Identifier
Modbus
Register
Modbus
Offset
(Offset to a
Base of 40001)
kW – Real Power defined as KiloWatts
is RMS volts times the RMS current divided by 1000, where the voltage wave and the current wave are in phase (zero degrees phase shift). It
is the measure of unidirectional rate of energy transfer from source to load (if positive).
System Maximum Peak Demand (kW Demand System Max)
returns maximum demand value read since startup or reset of demand register
= kW Dmd max, signed, absolute, peak demand, in kW, BACnet
= kW Dmd max value, unsigned, absolute, peak demand, in kW
= positive kW Dmd max, unsigned, positive value, peak demand, in kW
= negative kW Dmd max, unsigned, negative value, peak demand, in kW
NOTES:
If Dmd value>0, Dmd positive = Dmd value, Dmd negative = 0
If Dmd value<0, Dmd negative = Dmd value, Dmd positive = 0
1000
‒
‒
‒
‒
44004
46004
47004
‒
4003
6003
7003
System Average Power Demand (kW Demand System Now)
returns new value every minute, will compare and post to min/max registers
= kW Dmd now, unsigned, avg power, most recent dmd window, in kW, BACnet
= kW Dmd now value, unsigned, avg power, most recent dmd window, kW
= positive kW Dmd now, unsigned, avg power, most recent dmd window, kW
= negative kW Dmd now, unsigned, avg power, most recent dmd window, kW
NOTES:
If Dmd value>0, Dmd positive = Dmd value, Dmd negative = 0
If Dmd value<0, Dmd negative = Dmd value, Dmd positive = 0
1010
‒
‒
‒
‒
44005
46005
47005
‒
4004
6004
7004
System Minimum Power Demand (kW Demand System Min)
returns minimum demand value read since startup or reset of demand register
= kW Dmd min, unsigned, avg power, most recent dmd window, in kW, BACnet
= kW Dmd min value, unsigned, avg power, most recent dmd window, kW
= positive kW Dmd min, unsigned, avg power, most recent dmd window, kW
= negative kW Dmd min, unsigned, avg power, most recent dmd window, kW
NOTES:
If Dmd value>0, Dmd positive = Dmd value, Dmd negative = 0
If Dmd value<0, Dmd negative = Dmd value, Dmd positive = 0
1020
‒
‒
‒
‒
44081
46081
47081
‒
4080
6080
7080
System Total True Power (kW System)
equals ABS(kW L1) + ABS(kW L2) + ABS(kW L3), in kW
= kW Sys, signed, absolute, in kW, BACnet
= kW Sys value, unsigned, total instantaneous true power, in kW
= positive kW Sys, unsigned, positive instantaneous true power, in kW
= negative kW Sys, unsigned, negative instantaneous true power, in kW
NOTES:
If kW sys value>0, kW sys positive = kW sys, kW sys negative = 0
If kW sys value<0, kW sys negative = kW sys, kW sys positive = 0
1030
‒
‒
‒
‒
44003
46003
47003
‒
4002
6002
7002
System Net Power (kW System Net)
= signed, net value of (kW L1 + kW L2 + kW L3) in kW, BACnet
1031
‒
‒
System Average Power Draw (kW System Avg)
kWh System/(Time since Reset/3600 sec/hour, in kW (resettable)
= avg kW, total net, signed, BACnet
= positive avg kW value, signed net, BACnet
= negative avg kW value, signed net, BACnet
= avg kW value, unsigned
= positive avg kW value, unsigned
= negative avg kW value, unsigned
1060
1080
1090
‒
‒
‒
‒
‒
‒
44080
46080
47080
‒
‒
‒
4079
6079
7079